/brz/remove-bazaar

To get this branch, use:
bzr branch http://gegoxaren.bato24.eu/bzr/brz/remove-bazaar
2466.6.1 by Ian Clatworthy
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======================
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Bazaar Developer Guide
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======================
974.1.26 by aaron.bentley at utoronto
merged mbp@sourcefrog.net-20050817233101-0939da1cf91f2472
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3314.1.1 by Martin Pool
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This document describes the Bazaar internals and the development process.  
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It's meant for people interested in developing Bazaar, and some parts will
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also be useful to people developing Bazaar plugins.
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If you have any questions or something seems to be incorrect, unclear or
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missing, please talk to us in ``irc://irc.freenode.net/#bzr``, or write to
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the Bazaar mailing list.  To propose a correction or addition to this
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document, send a merge request or new text to the mailing list.
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The current version of this document is available in the file 
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``doc/developers/HACKING.txt`` in the source tree, or at
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http://doc.bazaar-vcs.org/bzr.dev/en/developer-guide/HACKING.html
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1393.1.53 by Martin Pool
- notes from coding-convention discussion
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.. contents::
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2466.6.1 by Ian Clatworthy
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Getting Started
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###############
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Exploring the Bazaar Platform
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=============================
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Before making changes, it's a good idea to explore the work already
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done by others. Perhaps the new feature or improvement you're looking
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for is available in another plug-in already? If you find a bug,
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perhaps someone else has already fixed it?
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To answer these questions and more, take a moment to explore the
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overall Bazaar Platform. Here are some links to browse:
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* The Plugins page on the Wiki - http://bazaar-vcs.org/BzrPlugins
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* The Bazaar product family on Launchpad - https://launchpad.net/bazaar
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* Bug Tracker for the core product - https://bugs.launchpad.net/bzr/
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* Blueprint Tracker for the core product - https://blueprints.launchpad.net/bzr/
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If nothing else, perhaps you'll find inspiration in how other developers
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have solved their challenges.
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Planning and Discussing Changes
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===============================
49
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There is a very active community around Bazaar. Mostly we meet on IRC
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(#bzr on irc.freenode.net) and on the mailing list. To join the Bazaar
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community, see http://bazaar-vcs.org/BzrSupport.
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If you are planning to make a change, it's a very good idea to mention it
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on the IRC channel and/or on the mailing list. There are many advantages
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to involving the community before you spend much time on a change.
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These include:
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* you get to build on the wisdom on others, saving time
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* if others can direct you to similar code, it minimises the work to be done 
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* it assists everyone in coordinating direction, priorities and effort.
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In summary, maximising the input from others typically minimises the
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total effort required to get your changes merged. The community is
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friendly, helpful and always keen to welcome newcomers.
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Bazaar Development in a Nutshell
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================================
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Looking for a 10 minute introduction to submitting a change?
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See http://bazaar-vcs.org/BzrGivingBack.
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TODO: Merge that Wiki page into this document.
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Understanding the Development Process
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=====================================
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The development team follows many best-practices including:
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* a public roadmap and planning process in which anyone can participate
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* time based milestones everyone can work towards and plan around
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* extensive code review and feedback to contributors
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* complete and rigorous test coverage on any code contributed
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* automated validation that all tests still pass before code is merged
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  into the main code branch.
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The key tools we use to enable these practices are:
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* Launchpad - https://launchpad.net/
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* Bazaar - http://bazaar-vcs.org/
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* Bundle Buggy - http://bundlebuggy.aaronbentley.com/
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* Patch Queue Manager - https://launchpad.net/pqm/
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For further information, see http://bazaar-vcs.org/BzrDevelopment.
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A Closer Look at the Merge & Review Process
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===========================================
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If you'd like to propose a change, please post to the
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bazaar@lists.canonical.com list with a bundle, patch, or link to a
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branch. Put '[PATCH]' or '[MERGE]' in the subject so Bundle Buggy
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can pick it out, and explain the change in the email message text.
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Remember to update the NEWS file as part of your change if it makes any
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changes visible to users or plugin developers. Please include a diff
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against mainline if you're giving a link to a branch.
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You can generate a bundle like this::
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  bzr bundle > mybundle.patch
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A .patch extension is recommended instead of .bundle as many mail clients
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will send the latter as a binary file. If a bundle would be too long or your
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mailer mangles whitespace (e.g. implicitly converts Unix newlines to DOS
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newlines), use the merge-directive command instead like this::
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  bzr merge-directive http://bazaar-vcs.org http://example.org/my_branch > my_directive.patch
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See the help for details on the arguments to merge-directive.
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Please do **NOT** put [PATCH] or [MERGE] in the subject line if you don't
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want it to be merged. If you want comments from developers rather than
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to be merged, you can put '[RFC]' in the subject line.
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Anyone is welcome to review code.  There are broadly three gates for
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code to get in:
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 * Doesn't reduce test coverage: if it adds new methods or commands,
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   there should be tests for them.  There is a good test framework
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   and plenty of examples to crib from, but if you are having trouble
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   working out how to test something feel free to post a draft patch
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   and ask for help.
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 * Doesn't reduce design clarity, such as by entangling objects
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   we're trying to separate.  This is mostly something the more
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   experienced reviewers need to help check.
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 * Improves bugs, features, speed, or code simplicity.
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Code that goes in should pass all three. The core developers take care
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to keep the code quality high and understandable while recognising that
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perfect is sometimes the enemy of good. (It is easy for reviews to make
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people notice other things which should be fixed but those things should
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not hold up the original fix being accepted. New things can easily be
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recorded in the Bug Tracker instead.)
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Anyone can "vote" on the mailing list. Core developers can also vote using
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Bundle Buggy. Here are the voting codes and their explanations.
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:approve:  Reviewer wants this submission merged.
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:tweak:    Reviewer wants this submission merged with small changes. (No
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  re-review required.)
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:abstain:  Reviewer does not intend to vote on this patch.
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:resubmit: Please make changes and resubmit for review.
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:reject:   Reviewer doesn't want this kind of change merged.
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:comment:  Not really a vote. Reviewer just wants to comment, for now.
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If a change gets two approvals from core reviewers, and no rejections,
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then it's OK to come in.  Any of the core developers can bring it into the
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bzr.dev trunk and backport it to maintenance branches if required.  The
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Release Manager will merge the change into the branch for a pending
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release, if any. As a guideline, core developers usually merge their own
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changes and volunteer to merge other contributions if they were the second
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reviewer to agree to a change.
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To track the progress of proposed changes, use Bundle Buggy. See
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http://bundlebuggy.aaronbentley.com/help for a link to all the
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outstanding merge requests together with an explanation of the columns.
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Bundle Buggy will also mail you a link to track just your change.
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Preparing a Sandbox for Making Changes to Bazaar
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================================================
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Bazaar supports many ways of organising your work. See
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http://bazaar-vcs.org/SharedRepositoryLayouts for a summary of the
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popular alternatives.
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Of course, the best choice for you will depend on numerous factors:
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the number of changes you may be making, the complexity of the changes, etc.
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As a starting suggestion though:
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* create a local copy of the main development branch (bzr.dev) by using
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  this command::
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    bzr branch http://bazaar-vcs.org/bzr/bzr.dev/ bzr.dev
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* keep your copy of bzr.dev prestine (by not developing in it) and keep
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  it up to date (by using bzr pull)
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* create a new branch off your local bzr.dev copy for each issue
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  (bug or feature) you are working on.
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This approach makes it easy to go back and make any required changes
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after a code review. Resubmitting the change is then simple with no
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risk of accidentially including edits related to other issues you may
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be working on. After the changes for an issue are accepted and merged,
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the associated branch can be deleted or archived as you wish.
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Navigating the Code Base
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========================
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TODO: List and describe in one line the purpose of each directory
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inside an installation of bzr.
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TODO: Refer to a central location holding an up to date copy of the API
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documentation generated by epydoc, e.g. something like
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http://starship.python.net/crew/mwh/bzrlibapi/bzrlib.html.
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Testing Bazaar
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##############
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2466.6.3 by Ian Clatworthy
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The Importance of Testing
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=========================
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Reliability is a critical success factor for any Version Control System.
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We want Bazaar to be highly reliable across multiple platforms while
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evolving over time to meet the needs of its community. 
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In a nutshell, this is want we expect and encourage:
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* New functionality should have test cases.  Preferably write the
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  test before writing the code.
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  In general, you can test at either the command-line level or the
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  internal API level.  See Writing tests below for more detail.
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* Try to practice Test-Driven Development: before fixing a bug, write a
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  test case so that it does not regress.  Similarly for adding a new
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  feature: write a test case for a small version of the new feature before
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  starting on the code itself.  Check the test fails on the old code, then
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  add the feature or fix and check it passes.
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By doing these things, the Bazaar team gets increased confidence that
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changes do what they claim to do, whether provided by the core team or
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by community members. Equally importantly, we can be surer that changes
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down the track do not break new features or bug fixes that you are
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contributing today.
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As of May 2007, Bazaar ships with a test suite containing over 6000 tests
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and growing. We are proud of it and want to remain so. As community
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members, we all benefit from it. Would you trust version control on
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your project to a product *without* a test suite like Bazaar has?
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Running the Test Suite
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======================
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Currently, bzr selftest is used to invoke tests.
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You can provide a pattern argument to run a subset. For example, 
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to run just the blackbox tests, run::
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  ./bzr selftest -v blackbox
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To skip a particular test (or set of tests), use the --exclude option
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(shorthand -x) like so::
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  ./bzr selftest -v -x blackbox  
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To ensure that all tests are being run and succeeding, you can use the
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--strict option which will fail if there are any missing features or known
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failures, like so::
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  ./bzr selftest --strict
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To list tests without running them, use the --list-only option like so::
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  ./bzr selftest --list-only
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This option can be combined with other selftest options (like -x) and
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filter patterns to understand their effect.
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Writing Tests
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=============
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In general tests should be placed in a file named test_FOO.py where 
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FOO is the logical thing under test. That file should be placed in the
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tests subdirectory under the package being tested.
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For example, tests for merge3 in bzrlib belong in bzrlib/tests/test_merge3.py.
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See bzrlib/tests/test_sampler.py for a template test script.
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Tests can be written for the UI or for individual areas of the library.
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Choose whichever is appropriate: if adding a new command, or a new command 
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option, then you should be writing a UI test.  If you are both adding UI
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functionality and library functionality, you will want to write tests for 
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both the UI and the core behaviours.  We call UI tests 'blackbox' tests
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and they are found in ``bzrlib/tests/blackbox/*.py``. 
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When writing blackbox tests please honour the following conventions:
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 1. Place the tests for the command 'name' in
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    bzrlib/tests/blackbox/test_name.py. This makes it easy for developers
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    to locate the test script for a faulty command.
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 2. Use the 'self.run_bzr("name")' utility function to invoke the command
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    rather than running bzr in a subprocess or invoking the
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    cmd_object.run() method directly. This is a lot faster than
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    subprocesses and generates the same logging output as running it in a
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    subprocess (which invoking the method directly does not).
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 3. Only test the one command in a single test script. Use the bzrlib 
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    library when setting up tests and when evaluating the side-effects of
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    the command. We do this so that the library api has continual pressure
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    on it to be as functional as the command line in a simple manner, and
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    to isolate knock-on effects throughout the blackbox test suite when a
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    command changes its name or signature. Ideally only the tests for a
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    given command are affected when a given command is changed.
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 4. If you have a test which does actually require running bzr in a
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    subprocess you can use ``run_bzr_subprocess``. By default the spawned
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    process will not load plugins unless ``--allow-plugins`` is supplied.
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Doctests
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--------
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We make selective use of doctests__.  In general they should provide 
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*examples* within the API documentation which can incidentally be tested.  We 
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don't try to test every important case using doctests -- regular Python
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tests are generally a better solution.
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Most of these are in ``bzrlib/doc/api``.  More additions are welcome.
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  __ http://docs.python.org/lib/module-doctest.html
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Skipping tests and test requirements
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------------------------------------
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In our enhancements to unittest we allow for some addition results beyond
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just success or failure.
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If a test can't be run, it can say that it's skipped.  This is typically
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used in parameterized tests - for example if a transport doesn't support
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setting permissions, we'll skip the tests that relating to that.  ::
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    try:
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        return self.branch_format.initialize(repo.bzrdir)
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    except errors.UninitializableFormat:
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        raise tests.TestSkipped('Uninitializable branch format')
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Raising TestSkipped is a good idea when you want to make it clear that the
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test was not run, rather than just returning which makes it look as if it
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was run and passed.
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Several different cases are distinguished:
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TestSkipped
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        Generic skip; the only type that was present up to bzr 0.18.
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TestNotApplicable
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        The test doesn't apply to the parameters with which it was run.
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        This is typically used when the test is being applied to all
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        implementations of an interface, but some aspects of the interface
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        are optional and not present in particular concrete
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        implementations.  (Some tests that should raise this currently
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        either silently return or raise TestSkipped.)  Another option is
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        to use more precise parameterization to avoid generating the test
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        at all.
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TestPlatformLimit
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        **(Not implemented yet)**
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        The test can't be run because of an inherent limitation of the
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        environment, such as not having symlinks or not supporting
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        unicode.
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UnavailableFeature
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        The test can't be run because a dependency (typically a Python
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        library) is not available in the test environment.  These
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        are in general things that the person running the test could fix 
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        by installing the library.  It's OK if some of these occur when 
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        an end user runs the tests or if we're specifically testing in a
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        limited environment, but a full test should never see them.
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KnownFailure
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        The test exists but is known to fail, for example because the 
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        code to fix it hasn't been run yet.  Raising this allows 
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        you to distinguish these failures from the ones that are not 
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        expected to fail.  This could be conditionally raised if something
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        is broken on some platforms but not on others.
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We plan to support three modes for running the test suite to control the
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interpretation of these results.  Strict mode is for use in situations
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like merges to the mainline and releases where we want to make sure that
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everything that can be tested has been tested.  Lax mode is for use by
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developers who want to temporarily tolerate some known failures.  The
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default behaviour is obtained by ``bzr selftest`` with no options, and
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also (if possible) by running under another unittest harness.
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======================= ======= ======= ========
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result                  strict  default lax
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======================= ======= ======= ========
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TestSkipped             pass    pass    pass
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TestNotApplicable       pass    pass    pass
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TestPlatformLimit       pass    pass    pass
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TestDependencyMissing   fail    pass    pass
2729.1.6 by Martin Pool
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KnownFailure            fail    pass    pass
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======================= ======= ======= ========
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Test feature dependencies
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-------------------------
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Rather than manually checking the environment in each test, a test class
420
can declare its dependence on some test features.  The feature objects are
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checked only once for each run of the whole test suite.
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For historical reasons, as of May 2007 many cases that should depend on
424
features currently raise TestSkipped.)
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::
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    class TestStrace(TestCaseWithTransport):
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        _test_needs_features = [StraceFeature]
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This means all tests in this class need the feature.  The feature itself
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should provide a ``_probe`` method which is called once to determine if
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it's available.
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These should generally be equivalent to either TestDependencyMissing or
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sometimes TestPlatformLimit.
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2475.2.3 by Martin Pool
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Known failures
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--------------
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Known failures are when a test exists but we know it currently doesn't
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work, allowing the test suite to still pass.  These should be used with
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care, we don't want a proliferation of quietly broken tests.  It might be
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appropriate to use them if you've committed a test for a bug but not the
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fix for it, or if something works on Unix but not on Windows.
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2513.1.9 by Martin Pool
Exception testing review comments
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Testing exceptions and errors
451
-----------------------------
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Doc testing of exceptions
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It's important to test handling of errors and exceptions.  Because this
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code is often not hit in ad-hoc testing it can often have hidden bugs --
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it's particularly common to get NameError because the exception code
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references a variable that has since been renamed.
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.. TODO: Something about how to provoke errors in the right way?
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In general we want to test errors at two levels:
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1. A test in ``test_errors.py`` checking that when the exception object is
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   constructed with known parameters it produces an expected string form.
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   This guards against mistakes in writing the format string, or in the
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   ``str`` representations of its parameters.  There should be one for
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   each exception class.
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2. Tests that when an api is called in a particular situation, it raises
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   an error of the expected class.  You should typically use
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   ``assertRaises``, which in the Bazaar test suite returns the exception
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   object to allow you to examine its parameters.  
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In some cases blackbox tests will also want to check error reporting.  But
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it can be difficult to provoke every error through the commandline
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interface, so those tests are only done as needed -- eg in response to a
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Exception testing review comments
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particular bug or if the error is reported in an unusual way(?)  Blackbox
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tests should mostly be testing how the command-line interface works, so
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should only test errors if there is something particular to the cli in how
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they're displayed or handled.
2513.1.8 by Martin Pool
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2475.2.3 by Martin Pool
Merge ian's HACKING updates
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2592.3.242 by Martin Pool
New method TestCase.call_catch_warnings
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Testing warnings
483
----------------
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The Python ``warnings`` module is used to indicate a non-fatal code
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problem.  Code that's expected to raise a warning can be tested through
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callCatchWarnings.
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The test suite can be run with ``-Werror`` to check no unexpected errors
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occur.
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However, warnings should be used with discretion.  It's not an appropriate
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way to give messages to the user, because the warning is normally shown
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only once per source line that causes the problem.  You should also think
495
about whether the warning is serious enought that it should be visible to
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users who may not be able to fix it.
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Interface implementation testing and test scenarios
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---------------------------------------------------
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There are several cases in Bazaar of multiple implementations of a common 
503
conceptual interface.  ("Conceptual" because 
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it's not necessary for all the implementations to share a base class,
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though they often do.)  Examples include transports and the working tree,
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branch and repository classes. 
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In these cases we want to make sure that every implementation correctly
509
fulfils the interface requirements.  For example, every Transport should
510
support the ``has()`` and ``get()`` and ``clone()`` methods.  We have a
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sub-suite of tests in ``test_transport_implementations``.  (Most
512
per-implementation tests are in submodules of ``bzrlib.tests``, but not
513
the transport tests at the moment.)  
514
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These tests are repeated for each registered Transport, by generating a
516
new TestCase instance for the cross product of test methods and transport
517
implementations.  As each test runs, it has ``transport_class`` and
518
``transport_server`` set to the class it should test.  Most tests don't
519
access these directly, but rather use ``self.get_transport`` which returns
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a transport of the appropriate type.
521
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The goal is to run per-implementation only tests that relate to that
523
particular interface.  Sometimes we discover a bug elsewhere that happens
524
with only one particular transport.  Once it's isolated, we can consider 
525
whether a test should be added for that particular implementation,
526
or for all implementations of the interface.
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The multiplication of tests for different implementations is normally 
529
accomplished by overriding the ``test_suite`` function used to load 
530
tests from a module.  This function typically loads all the tests,
531
then applies a TestProviderAdapter to them, which generates a longer 
532
suite containing all the test variations.
533
534
2729.1.2 by Martin Pool
Add new multiply_tests_from_modules to give a simpler interface to test scenarios
535
Test scenarios
536
--------------
537
538
Some utilities are provided for generating variations of tests.  This can
539
be used for per-implementation tests, or other cases where the same test
540
code needs to run several times on different scenarios.
541
542
The general approach is to define a class that provides test methods,
543
which depend on attributes of the test object being pre-set with the
544
values to which the test should be applied.  The test suite should then
545
also provide a list of scenarios in which to run the tests.
546
547
Typically ``multiply_tests_from_modules`` should be called from the test
548
module's ``test_suite`` function.
549
550
2466.6.2 by Ian Clatworthy
Incorporate feedback from LarstiQ
551
Essential Domain Classes
552
########################
553
554
Introducing the Object Model
555
============================
556
557
The core domain objects within the bazaar model are:
558
559
* Transport
560
561
* Branch
562
563
* Repository
564
565
* WorkingTree
566
567
Transports are explained below. See http://bazaar-vcs.org/Classes/
568
for an introduction to the other key classes.
569
570
Using Transports
571
================
572
573
The ``Transport`` layer handles access to local or remote directories.
574
Each Transport object acts like a logical connection to a particular
575
directory, and it allows various operations on files within it.  You can
576
*clone* a transport to get a new Transport connected to a subdirectory or
577
parent directory.
578
579
Transports are not used for access to the working tree.  At present
580
working trees are always local and they are accessed through the regular
581
Python file io mechanisms.
582
583
Filenames vs URLs
584
-----------------
585
586
Transports work in URLs.  Take note that URLs are by definition only
587
ASCII - the decision of how to encode a Unicode string into a URL must be
588
taken at a higher level, typically in the Store.  (Note that Stores also
589
escape filenames which cannot be safely stored on all filesystems, but
590
this is a different level.)
591
592
The main reason for this is that it's not possible to safely roundtrip a
593
URL into Unicode and then back into the same URL.  The URL standard
594
gives a way to represent non-ASCII bytes in ASCII (as %-escapes), but
595
doesn't say how those bytes represent non-ASCII characters.  (They're not
596
guaranteed to be UTF-8 -- that is common but doesn't happen everywhere.)
597
598
For example if the user enters the url ``http://example/%e0`` there's no
599
way to tell whether that character represents "latin small letter a with
600
grave" in iso-8859-1, or "latin small letter r with acute" in iso-8859-2
601
or malformed UTF-8.  So we can't convert their URL to Unicode reliably.
602
603
Equally problematic if we're given a url-like string containing non-ascii
604
characters (such as the accented a) we can't be sure how to convert that
605
to the correct URL, because we don't know what encoding the server expects
606
for those characters.  (Although this is not totally reliable we might still
607
accept these and assume they should be put into UTF-8.)
608
609
A similar edge case is that the url ``http://foo/sweet%2Fsour`` contains
610
one directory component whose name is "sweet/sour".  The escaped slash is
611
not a directory separator.  If we try to convert URLs to regular Unicode
612
paths this information will be lost.
613
614
This implies that Transports must natively deal with URLs; for simplicity
615
they *only* deal with URLs and conversion of other strings to URLs is done
616
elsewhere.  Information they return, such as from ``list_dir``, is also in
617
the form of URL components.
618
619
620
Core Topics
621
###########
622
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
623
Evolving Interfaces
624
===================
1393.1.54 by Martin Pool
- more hacking notes on evolving interfaces
625
1534.2.4 by Robert Collins
Update NEWS and HACKING for the symbol_versioning module.
626
We have a commitment to 6 months API stability - any supported symbol in a
627
release of bzr MUST NOT be altered in any way that would result in
628
breaking existing code that uses it. That means that method names,
629
parameter ordering, parameter names, variable and attribute names etc must
630
not be changed without leaving a 'deprecated forwarder' behind. This even
631
applies to modules and classes.
632
633
If you wish to change the behaviour of a supported API in an incompatible
2063.3.1 by wang
fix typos
634
way, you need to change its name as well. For instance, if I add an optional keyword
1534.2.4 by Robert Collins
Update NEWS and HACKING for the symbol_versioning module.
635
parameter to branch.commit - that's fine. On the other hand, if I add a
636
keyword parameter to branch.commit which is a *required* transaction
637
object, I should rename the API - i.e. to 'branch.commit_transaction'. 
638
639
When renaming such supported API's, be sure to leave a deprecated_method (or
640
_function or ...) behind which forwards to the new API. See the
641
bzrlib.symbol_versioning module for decorators that take care of the
642
details for you - such as updating the docstring, and issuing a warning
643
when the old api is used.
644
2063.3.1 by wang
fix typos
645
For unsupported API's, it does not hurt to follow this discipline, but it's
1534.2.4 by Robert Collins
Update NEWS and HACKING for the symbol_versioning module.
646
not required. Minimally though, please try to rename things so that
647
callers will at least get an AttributeError rather than weird results.
648
1393.1.54 by Martin Pool
- more hacking notes on evolving interfaces
649
2825.3.1 by Martin Pool
Developer docs about deprecation
650
Deprecation decorators
651
----------------------
652
653
``bzrlib.symbol_versioning`` provides decorators that can be attached to
654
methods, functions, and other interfaces to indicate that they should no
655
longer be used.
656
2825.3.4 by Martin Pool
Better explanation of deprecation
657
To deprecate a static method you must call ``deprecated_function``
658
(**not** method), after the staticmethod call::
2825.3.1 by Martin Pool
Developer docs about deprecation
659
660
    @staticmethod
661
    @deprecated_function(zero_ninetyone)
662
    def create_repository(base, shared=False, format=None):
663
664
When you deprecate an API, you should not just delete its tests, because
665
then we might introduce bugs in them.  If the API is still present at all,
666
it should still work.  The basic approach is to use
667
``TestCase.applyDeprecated`` which in one step checks that the API gives
668
the expected deprecation message, and also returns the real result from
669
the method, so that tests can keep running.
670
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
671
Coding Style Guidelines
672
=======================
1393.1.53 by Martin Pool
- notes from coding-convention discussion
673
3376.2.2 by Martin Pool
Add documentation of assert statement ban
674
hasattr and getattr
675
-------------------
2974.1.1 by Martin Pool
HACKING: say not to use hasattr()
676
677
``hasattr`` should not be used because it swallows exceptions including
678
``KeyboardInterrupt``.  Instead, say something like ::
679
680
  if getattr(thing, 'name', None) is None
681
682
2795.1.1 by Martin Pool
Document code layout stuff
683
Code layout
684
-----------
685
1393.1.53 by Martin Pool
- notes from coding-convention discussion
686
Please write PEP-8__ compliant code.  
687
2795.1.1 by Martin Pool
Document code layout stuff
688
__ http://www.python.org/peps/pep-0008.html
689
1393.1.53 by Martin Pool
- notes from coding-convention discussion
690
One often-missed requirement is that the first line of docstrings
691
should be a self-contained one-sentence summary.
692
2795.1.1 by Martin Pool
Document code layout stuff
693
We use 4 space indents for blocks, and never use tab characters.  (In vim,
694
``set expandtab``.)
695
696
Lines should be no more than 79 characters if at all possible.
697
Lines that continue a long statement may be indented in either of 
698
two ways:
699
700
within the parenthesis or other character that opens the block, e.g.::
701
702
    my_long_method(arg1,
703
                   arg2,
704
                   arg3)
705
706
or indented by four spaces::
707
708
    my_long_method(arg1,
709
        arg2,
710
        arg3)
711
712
The first is considered clearer by some people; however it can be a bit
713
harder to maintain (e.g. when the method name changes), and it does not
714
work well if the relevant parenthesis is already far to the right.  Avoid
715
this::
716
717
     self.legbone.kneebone.shinbone.toebone.shake_it(one,
718
                                                     two,
719
                                                     three)
720
721
but rather ::
722
723
     self.legbone.kneebone.shinbone.toebone.shake_it(one,
724
         two,
725
         three)
726
727
or ::
728
729
     self.legbone.kneebone.shinbone.toebone.shake_it(
730
         one, two, three)
731
732
For long lists, we like to add a trailing comma and put the closing
733
character on the following line.  This makes it easier to add new items in
734
future::
735
736
    from bzrlib.goo import (
737
        jam,
738
        jelly,
739
        marmalade,
740
        )
1393.1.53 by Martin Pool
- notes from coding-convention discussion
741
2795.1.3 by Martin Pool
clarify spacing for function parameters
742
There should be spaces between function paramaters, but not between the
743
keyword name and the value::
744
745
    call(1, 3, cheese=quark)
1393.1.53 by Martin Pool
- notes from coding-convention discussion
746
2795.1.2 by Martin Pool
emacs indent additions from vila
747
In emacs::
748
749
    ;(defface my-invalid-face
750
    ;  '((t (:background "Red" :underline t)))
751
    ;  "Face used to highlight invalid constructs or other uglyties"
752
    ;  )
753
754
    (defun my-python-mode-hook ()
755
     ;; setup preferred indentation style.
756
     (setq fill-column 79)
757
     (setq indent-tabs-mode nil) ; no tabs, never, I will not repeat
758
    ;  (font-lock-add-keywords 'python-mode
759
    ;                         '(("^\\s *\t" . 'my-invalid-face) ; Leading tabs
760
    ;                            ("[ \t]+$" . 'my-invalid-face)  ; Trailing spaces
761
    ;                            ("^[ \t]+$" . 'my-invalid-face)); Spaces only
762
    ;                          )
763
     )
764
765
    (add-hook 'python-mode-hook 'my-python-mode-hook)
766
767
The lines beginning with ';' are comments. They can be activated
768
if one want to have a strong notice of some tab/space usage
769
violations.
770
771
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
772
Module Imports
773
--------------
774
775
* Imports should be done at the top-level of the file, unless there is
776
  a strong reason to have them lazily loaded when a particular
777
  function runs.  Import statements have a cost, so try to make sure
778
  they don't run inside hot functions.
779
780
* Module names should always be given fully-qualified,
781
  i.e. ``bzrlib.hashcache`` not just ``hashcache``.
782
1393.1.53 by Martin Pool
- notes from coding-convention discussion
783
784
Naming
785
------
786
2625.3.1 by Ian Clatworthy
Clarify the use of underscore in the naming convention
787
Functions, methods or members that are "private" to bzrlib are given
788
a leading underscore prefix.  Names without a leading underscore are
789
public not just across modules but to programmers using bzrlib as an
790
API. As a consequence, a leading underscore is appropriate for names
791
exposed across modules but that are not to be exposed to bzrlib API
792
programmers.
1393.1.53 by Martin Pool
- notes from coding-convention discussion
793
794
We prefer class names to be concatenated capital words (``TestCase``)
795
and variables, methods and functions to be lowercase words joined by
796
underscores (``revision_id``, ``get_revision``).
797
798
For the purposes of naming some names are treated as single compound
799
words: "filename", "revno".
800
801
Consider naming classes as nouns and functions/methods as verbs.
802
2221.4.7 by Aaron Bentley
Add suggestion to HACKING
803
Try to avoid using abbreviations in names, because there can be
804
inconsistency if other people use the full name.
805
1393.1.53 by Martin Pool
- notes from coding-convention discussion
806
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
807
Standard Names
1393.1.53 by Martin Pool
- notes from coding-convention discussion
808
--------------
809
810
``revision_id`` not ``rev_id`` or ``revid``
811
812
Functions that transform one thing to another should be named ``x_to_y``
813
(not ``x2y`` as occurs in some old code.)
814
1098 by Martin Pool
- notes on how output is written
815
1185.16.85 by mbp at sourcefrog
- rules for using destructors
816
Destructors
817
-----------
818
1185.16.150 by Martin Pool
Improved description of python exception policies
819
Python destructors (``__del__``) work differently to those of other
820
languages.  In particular, bear in mind that destructors may be called
821
immediately when the object apparently becomes unreferenced, or at some
822
later time, or possibly never at all.  Therefore we have restrictions on
823
what can be done inside them.
1185.16.85 by mbp at sourcefrog
- rules for using destructors
824
825
 0. Never use a __del__ method without asking Martin/Robert first.
826
827
 1. Never rely on a ``__del__`` method running.  If there is code that
828
    must run, do it from a ``finally`` block instead.
829
830
 2. Never ``import`` from inside a ``__del__`` method, or you may crash the
831
    interpreter!!
832
833
 3. In some places we raise a warning from the destructor if the object
834
    has not been cleaned up or closed.  This is considered OK: the warning
835
    may not catch every case but it's still useful sometimes.
836
837
1740.2.5 by Aaron Bentley
Merge from bzr.dev
838
Factories
839
---------
840
841
In some places we have variables which point to callables that construct
842
new instances.  That is to say, they can be used a lot like class objects,
843
but they shouldn't be *named* like classes:
844
845
> I think that things named FooBar should create instances of FooBar when
846
> called. Its plain confusing for them to do otherwise. When we have
847
> something that is going to be used as a class - that is, checked for via
848
> isinstance or other such idioms, them I would call it foo_class, so that
849
> it is clear that a callable is not sufficient. If it is only used as a
850
> factory, then yes, foo_factory is what I would use.
851
852
1911.4.15 by John Arbash Meinel
Updated HACKING and docstrings per Martin's suggestions
853
Registries
854
----------
855
856
Several places in Bazaar use (or will use) a registry, which is a 
857
mapping from names to objects or classes.  The registry allows for 
858
loading in registered code only when it's needed, and keeping
859
associated information such as a help string or description.
860
861
1996.1.20 by John Arbash Meinel
HACKING and NEWS
862
Lazy Imports
863
------------
864
865
To make startup time faster, we use the ``bzrlib.lazy_import`` module to
866
delay importing modules until they are actually used. ``lazy_import`` uses
867
the same syntax as regular python imports. So to import a few modules in a
868
lazy fashion do::
869
870
  from bzrlib.lazy_import import lazy_import
871
  lazy_import(globals(), """
872
  import os
873
  import subprocess
874
  import sys
875
  import time
876
877
  from bzrlib import (
878
     errors,
879
     transport,
1996.3.37 by John Arbash Meinel
Update HACKING and TODO
880
     revision as _mod_revision,
1996.1.20 by John Arbash Meinel
HACKING and NEWS
881
     )
882
  import bzrlib.transport
883
  import bzrlib.xml5
884
  """)
885
886
At this point, all of these exist as a ``ImportReplacer`` object, ready to
1996.3.37 by John Arbash Meinel
Update HACKING and TODO
887
be imported once a member is accessed. Also, when importing a module into
888
the local namespace, which is likely to clash with variable names, it is
2370.1.1 by Ian Clatworthy
Minor corrections to HACKING
889
recommended to prefix it as ``_mod_<module>``. This makes it clearer that
1996.3.37 by John Arbash Meinel
Update HACKING and TODO
890
the variable is a module, and these object should be hidden anyway, since
891
they shouldn't be imported into other namespaces.
1996.1.20 by John Arbash Meinel
HACKING and NEWS
892
893
894
Modules versus Members
895
~~~~~~~~~~~~~~~~~~~~~~
896
897
While it is possible for ``lazy_import()`` to import members of a module
2063.3.1 by wang
fix typos
898
when using the ``from module import member`` syntax, it is recommended to
1996.1.20 by John Arbash Meinel
HACKING and NEWS
899
only use that syntax to load sub modules ``from module import submodule``.
900
This is because variables and classes can frequently be used without
901
needing a sub-member for example::
902
903
  lazy_import(globals(), """
904
  from module import MyClass
905
  """)
906
907
  def test(x):
908
      return isinstance(x, MyClass)
909
910
This will incorrectly fail, because ``MyClass`` is a ``ImportReplacer``
911
object, rather than the real class.
912
913
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
914
Passing to Other Variables
1996.1.20 by John Arbash Meinel
HACKING and NEWS
915
~~~~~~~~~~~~~~~~~~~~~~~~~~
916
1996.1.26 by John Arbash Meinel
Update HACKING and docstrings
917
It also is incorrect to assign ``ImportReplacer`` objects to other variables.
1996.1.20 by John Arbash Meinel
HACKING and NEWS
918
Because the replacer only knows about the original name, it is unable to
919
replace other variables. The ``ImportReplacer`` class will raise an
1996.1.26 by John Arbash Meinel
Update HACKING and docstrings
920
``IllegalUseOfScopeReplacer`` exception if it can figure out that this
921
happened. But it requires accessing a member more than once from the new
922
variable, so some bugs are not detected right away.
1996.1.20 by John Arbash Meinel
HACKING and NEWS
923
924
2598.5.9 by Aaron Bentley
Update NEWS and HACKING
925
The Null revision
926
-----------------
927
928
The null revision is the ancestor of all revisions.  Its revno is 0, its
929
revision-id is ``null:``, and its tree is the empty tree.  When referring
930
to the null revision, please use ``bzrlib.revision.NULL_REVISION``.  Old
931
code sometimes uses ``None`` for the null revision, but this practice is
932
being phased out.
933
934
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
935
Getting Input
936
=============
937
938
Processing Command Lines
939
------------------------
940
941
bzrlib has a standard framework for parsing command lines and calling
942
processing routines associated with various commands. See builtins.py
2466.6.2 by Ian Clatworthy
Incorporate feedback from LarstiQ
943
for numerous examples.
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
944
945
946
Standard Parameter Types
947
------------------------
948
949
There are some common requirements in the library: some parameters need to be
950
unicode safe, some need byte strings, and so on. At the moment we have
951
only codified one specific pattern: Parameters that need to be unicode
952
should be checked via ``bzrlib.osutils.safe_unicode``. This will coerce the
953
input into unicode in a consistent fashion, allowing trivial strings to be
954
used for programmer convenience, but not performing unpredictably in the
955
presence of different locales.
956
957
958
Writing Output
1098 by Martin Pool
- notes on how output is written
959
==============
960
961
(The strategy described here is what we want to get to, but it's not
962
consistently followed in the code at the moment.)
963
964
bzrlib is intended to be a generically reusable library.  It shouldn't
965
write messages to stdout or stderr, because some programs that use it
966
might want to display that information through a GUI or some other
967
mechanism.
968
969
We can distinguish two types of output from the library:
970
971
 1. Structured data representing the progress or result of an
972
    operation.  For example, for a commit command this will be a list
973
    of the modified files and the finally committed revision number
974
    and id.
975
976
    These should be exposed either through the return code or by calls
977
    to a callback parameter.
978
979
    A special case of this is progress indicators for long-lived
980
    operations, where the caller should pass a ProgressBar object.
981
982
 2. Unstructured log/debug messages, mostly for the benefit of the
983
    developers or users trying to debug problems.  This should always
984
    be sent through ``bzrlib.trace`` and Python ``logging``, so that
985
    it can be redirected by the client.
986
987
The distinction between the two is a bit subjective, but in general if
988
there is any chance that a library would want to see something as
989
structured data, we should make it so.
990
991
The policy about how output is presented in the text-mode client
992
should be only in the command-line tool.
1092.1.22 by Robert Collins
update hacking with some test foo
993
1418 by Robert Collins
merge martins latest
994
2598.1.1 by Martin Pool
Add test for and documentation of option style, fix up existing options to comply
995
996
Displaying help
997
===============
998
999
Bazaar has online help for various topics through ``bzr help COMMAND`` or
1000
equivalently ``bzr command -h``.  We also have help on command options,
1001
and on other help topics.  (See ``help_topics.py``.)
1002
1003
As for python docstrings, the first paragraph should be a single-sentence
1004
synopsis of the command.
1005
1006
The help for options should be one or more proper sentences, starting with
1007
a capital letter and finishing with a full stop (period).
1008
1009
All help messages and documentation should have two spaces between
1010
sentences.
1011
1012
1092.1.22 by Robert Collins
update hacking with some test foo
1013
Writing tests
1014
=============
2067.2.2 by John Arbash Meinel
Review comments from Robert
1015
1638.1.1 by Robert Collins
Update HACKING to reflect current test writing policy.
1016
In general tests should be placed in a file named test_FOO.py where 
1092.1.22 by Robert Collins
update hacking with some test foo
1017
FOO is the logical thing under test. That file should be placed in the
1018
tests subdirectory under the package being tested.
1019
1638.1.1 by Robert Collins
Update HACKING to reflect current test writing policy.
1020
For example, tests for merge3 in bzrlib belong in bzrlib/tests/test_merge3.py.
2370.1.1 by Ian Clatworthy
Minor corrections to HACKING
1021
See bzrlib/tests/test_sampler.py for a template test script.
1638.1.1 by Robert Collins
Update HACKING to reflect current test writing policy.
1022
1023
Tests can be written for the UI or for individual areas of the library.
1024
Choose whichever is appropriate: if adding a new command, or a new command 
1025
option, then you should be writing a UI test.  If you are both adding UI
1026
functionality and library functionality, you will want to write tests for 
1027
both the UI and the core behaviours.  We call UI tests 'blackbox' tests
1711.2.94 by John Arbash Meinel
Update HACKING to be rst compliant
1028
and they are found in ``bzrlib/tests/blackbox/*.py``. 
1638.1.1 by Robert Collins
Update HACKING to reflect current test writing policy.
1029
1030
When writing blackbox tests please honour the following conventions:
1031
1032
 1. Place the tests for the command 'name' in
1033
    bzrlib/tests/blackbox/test_name.py. This makes it easy for developers
1034
    to locate the test script for a faulty command.
1035
1036
 2. Use the 'self.run_bzr("name")' utility function to invoke the command
1037
    rather than running bzr in a subprocess or invoking the
1038
    cmd_object.run() method directly. This is a lot faster than
1039
    subprocesses and generates the same logging output as running it in a
1040
    subprocess (which invoking the method directly does not).
1041
 
1042
 3. Only test the one command in a single test script. Use the bzrlib 
1043
    library when setting up tests and when evaluating the side-effects of
1044
    the command. We do this so that the library api has continual pressure
1045
    on it to be as functional as the command line in a simple manner, and
1046
    to isolate knock-on effects throughout the blackbox test suite when a
2063.3.1 by wang
fix typos
1047
    command changes its name or signature. Ideally only the tests for a
1638.1.1 by Robert Collins
Update HACKING to reflect current test writing policy.
1048
    given command are affected when a given command is changed.
1393.1.61 by Martin Pool
doc
1049
2067.2.2 by John Arbash Meinel
Review comments from Robert
1050
 4. If you have a test which does actually require running bzr in a
1051
    subprocess you can use ``run_bzr_subprocess``. By default the spawned
1052
    process will not load plugins unless ``--allow-plugins`` is supplied.
1053
1054
2466.7.2 by Robert Collins
Document the user of TreeBuilder somewhat.
1055
Test support
1056
------------
1057
1058
We have a rich collection of tools to support writing tests. Please use
1059
them in preference to ad-hoc solutions as they provide portability and
1060
performance benefits.
1061
1062
TreeBuilder
1063
~~~~~~~~~~~
1064
1065
The ``TreeBuilder`` interface allows the construction of arbitrary trees
1066
with a declarative interface. A sample session might look like::
1067
1068
  tree = self.make_branch_and_tree('path')
1069
  builder = TreeBuilder()
1070
  builder.start_tree(tree)
1071
  builder.build(['foo', "bar/", "bar/file"])
1072
  tree.commit('commit the tree')
1073
  builder.finish_tree()
1074
1075
Please see bzrlib.treebuilder for more details.
1076
2466.7.7 by Robert Collins
Document basic usage.
1077
BranchBuilder
1078
~~~~~~~~~~~~~
1079
1080
The ``BranchBuilder`` interface allows the creation of test branches in a
1081
quick and easy manner. A sample session::
1082
1083
  builder = BranchBuilder(self.get_transport().clone('relpath'))
1084
  builder.build_commit()
1085
  builder.build_commit()
1086
  builder.build_commit()
1087
  branch = builder.get_branch()
1088
1089
Please see bzrlib.branchbuilder for more details.
2466.7.2 by Robert Collins
Document the user of TreeBuilder somewhat.
1090
1740.6.1 by Martin Pool
Remove Scratch objects used by doctests
1091
Doctests
1092
--------
1093
1094
We make selective use of doctests__.  In general they should provide 
1095
*examples* within the API documentation which can incidentally be tested.  We 
1096
don't try to test every important case using doctests -- regular Python
1097
tests are generally a better solution.
1098
1099
Most of these are in ``bzrlib/doc/api``.  More additions are welcome.
1100
1101
  __ http://docs.python.org/lib/module-doctest.html
1102
1103
1092.1.22 by Robert Collins
update hacking with some test foo
1104
Running tests
1105
=============
1106
Currently, bzr selftest is used to invoke tests.
1107
You can provide a pattern argument to run a subset. For example, 
1638.1.1 by Robert Collins
Update HACKING to reflect current test writing policy.
1108
to run just the blackbox tests, run::
1393.1.61 by Martin Pool
doc
1109
1638.1.1 by Robert Collins
Update HACKING to reflect current test writing policy.
1110
  ./bzr selftest -v blackbox
1393.1.61 by Martin Pool
doc
1111
2394.2.6 by Ian Clatworthy
completed blackbox tests
1112
To skip a particular test (or set of tests), use the --exclude option
1113
(shorthand -x) like so::
1114
1115
  ./bzr selftest -v -x blackbox  
1116
1117
To list tests without running them, use the --list-only option like so::
1118
1119
  ./bzr selftest --list-only
1120
1121
This option can be combined with other selftest options (like -x) and
1122
filter patterns to understand their effect.
1551.6.41 by Aaron Bentley
Add advice on skipping tests to HACKING
1123
1393.1.61 by Martin Pool
doc
1124
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
1125
Handling Errors and Exceptions
1126
==============================
1127
1128
Commands should return non-zero when they encounter circumstances that
1129
the user should really pay attention to - which includes trivial shell
1130
pipelines.
1131
1132
Recommended values are:
1133
1134
    0. OK.
1135
    1. Conflicts in merge-like operations, or changes are present in
2475.2.4 by Martin Pool
HACKING rest fixes from jam
1136
       diff-like operations. 
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
1137
    2. Unrepresentable diff changes (i.e. binary files that we cannot show 
2475.2.4 by Martin Pool
HACKING rest fixes from jam
1138
       a diff of).
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
1139
    3. An error or exception has occurred.
2713.2.2 by Martin Pool
Add mention of exitcode 4 for internal errors
1140
    4. An internal error occurred (one that shows a traceback.)
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
1141
1142
Errors are handled through Python exceptions. Exceptions should be defined
1143
inside bzrlib.errors, so that we can see the whole tree at a glance.
1144
1145
We broadly classify errors as either being either internal or not,
2475.2.4 by Martin Pool
HACKING rest fixes from jam
1146
depending on whether ``internal_error`` is set or not.  If we think it's our
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
1147
fault, we show a backtrace, an invitation to report the bug, and possibly
1148
other details.  This is the default for errors that aren't specifically
1149
recognized as being caused by a user error.  Otherwise we show a briefer
1150
message, unless -Derror was given.
1151
1152
Many errors originate as "environmental errors" which are raised by Python
1153
or builtin libraries -- for example IOError.  These are treated as being
1154
our fault, unless they're caught in a particular tight scope where we know
1155
that they indicate a user errors.  For example if the repository format
1156
is not found, the user probably gave the wrong path or URL.  But if one of
1157
the files inside the repository is not found, then it's our fault --
1158
either there's a bug in bzr, or something complicated has gone wrong in
1159
the environment that means one internal file was deleted.
1160
1161
Many errors are defined in ``bzrlib/errors.py`` but it's OK for new errors
1162
to be added near the place where they are used.
1163
1164
Exceptions are formatted for the user by conversion to a string
1165
(eventually calling their ``__str__`` method.)  As a convenience the
1166
``._fmt`` member can be used as a template which will be mapped to the
1167
error's instance dict.
1168
1169
New exception classes should be defined when callers might want to catch
1170
that exception specifically, or when it needs a substantially different
1171
format string.
1172
1173
Exception strings should start with a capital letter and should not have a
1174
final fullstop.  If long, they may contain newlines to break the text.
1175
1176
3376.2.3 by Martin Pool
Updated info about assertions
1177
Assertions
1178
----------
1179
1180
Do not use the Python ``assert`` statement, either in tests or elsewhere.
1181
A source test checks that it is not used.  It is ok to explicitly raise
1182
AssertionError.
1183
1184
Rationale:
1185
1186
 * It makes the behaviour vary depending on whether bzr is run with -O
1187
   or not, therefore giving a chance for bugs that occur in one case or
1188
   the other, several of which have already occurred: assertions with
1189
   side effects, code which can't continue unless the assertion passes,
1190
   cases where we should give the user a proper message rather than an
1191
   assertion failure.
1192
 * It's not that much shorter than an explicit if/raise.
1193
 * It tends to lead to fuzzy thinking about whether the check is
1194
   actually needed or not, and whether it's an internal error or not
1195
 * It tends to cause look-before-you-leap patterns.
1196
 * It's unsafe if the check is needed to protect the integrity of the
1197
   user's data.
1198
 * It tends to give poor messages since the developer can get by with
1199
   no explanatory text at all.
1200
 * We can't rely on people always running with -O in normal use, so we
1201
   can't use it for tests that are actually expensive.
1202
 * Expensive checks that help developers are better turned on from the
1203
   test suite or a -D flag.
1204
 * If used instead of ``self.assert*()`` in tests it makes them falsely pass with -O.
1205
1206
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
1207
Documenting Changes
1208
===================
1209
1210
When you change bzrlib, please update the relevant documentation for the
1211
change you made: Changes to commands should update their help, and
1212
possibly end user tutorials; changes to the core library should be
1213
reflected in API documentation.
1214
1215
NEWS File
1216
---------
1217
1218
If you make a user-visible change, please add a note to the NEWS file.
1219
The description should be written to make sense to someone who's just
1220
a user of bzr, not a developer: new functions or classes shouldn't be
1221
mentioned, but new commands, changes in behaviour or fixed nontrivial
1222
bugs should be listed.  See the existing entries for an idea of what
1223
should be done.
1224
1225
Within each release, entries in the news file should have the most
1226
user-visible changes first.  So the order should be approximately:
1227
1228
 * changes to existing behaviour - the highest priority because the 
1229
   user's existing knowledge is incorrect
1230
 * new features - should be brought to their attention
1231
 * bug fixes - may be of interest if the bug was affecting them, and
1232
   should include the bug number if any
1233
 * major documentation changes
1234
 * changes to internal interfaces
1235
1236
People who made significant contributions to each change are listed in
1237
parenthesis.  This can include reporting bugs (particularly with good
1238
details or reproduction recipes), submitting patches, etc.
1239
1240
Commands
1241
--------
1242
1243
The docstring of a command is used by ``bzr help`` to generate help output
1244
for the command. The list 'takes_options' attribute on a command is used by
1245
``bzr help`` to document the options for the command - the command
1246
docstring does not need to document them. Finally, the '_see_also'
1247
attribute on a command can be used to reference other related help topics.
1248
1249
API Documentation
1250
-----------------
1251
1252
Functions, methods, classes and modules should have docstrings
1253
describing how they are used. 
1254
1255
The first line of the docstring should be a self-contained sentence.
1256
1257
For the special case of Command classes, this acts as the user-visible
1258
documentation shown by the help command.
1259
1260
The docstrings should be formatted as reStructuredText_ (like this
1261
document), suitable for processing using the epydoc_ tool into HTML
1262
documentation.
1263
1264
.. _reStructuredText: http://docutils.sourceforge.net/rst.html
1265
.. _epydoc: http://epydoc.sourceforge.net/
1266
1267
1268
General Guidelines
1269
==================
1270
1271
Copyright
1272
---------
1273
1274
The copyright policy for bzr was recently made clear in this email (edited
1275
for grammatical correctness)::
1276
1277
    The attached patch cleans up the copyright and license statements in
1278
    the bzr source. It also adds tests to help us remember to add them
1279
    with the correct text.
1280
1281
    We had the problem that lots of our files were "Copyright Canonical
1282
    Development Ltd" which is not a real company, and some other variations
1283
    on this theme. Also, some files were missing the GPL statements.
1284
    
1285
    I want to be clear about the intent of this patch, since copyright can
1286
    be a little controversial.
1287
    
1288
    1) The big motivation for this is not to shut out the community, but
1289
    just to clean up all of the invalid copyright statements.
1290
    
1291
    2) It has been the general policy for bzr that we want a single
1292
    copyright holder for all of the core code. This is following the model
1293
    set by the FSF, which makes it easier to update the code to a new
1294
    license in case problems are encountered. (For example, if we want to
1295
    upgrade the project universally to GPL v3 it is much simpler if there is
1296
    a single copyright holder). It also makes it clearer if copyright is
1297
    ever debated, there is a single holder, which makes it easier to defend
1298
    in court, etc. (I think the FSF position is that if you assign them
1299
    copyright, they can defend it in court rather than you needing to, and
1300
    I'm sure Canonical would do the same).
1301
    As such, Canonical has requested copyright assignments from all of the
1302
    major contributers.
1303
    
1304
    3) If someone wants to add code and not attribute it to Canonical, there
1305
    is a specific list of files that are excluded from this check. And the
1306
    test failure indicates where that is, and how to update it.
1307
    
1308
    4) If anyone feels that I changed a copyright statement incorrectly, just
1309
    let me know, and I'll be happy to correct it. Whenever you have large
1310
    mechanical changes like this, it is possible to make some mistakes.
1311
    
1312
    Just to reiterate, this is a community project, and it is meant to stay
1313
    that way. Core bzr code is copyright Canonical for legal reasons, and
1314
    the tests are just there to help us maintain that.
1315
1316
1317
Miscellaneous Topics
1318
####################
1319
1320
Debugging
1321
=========
1322
1323
Bazaar has a few facilities to help debug problems by going into pdb_, the
1324
Python debugger.
1325
1326
.. _pdb: http://docs.python.org/lib/debugger-commands.html
1327
1328
If the ``BZR_PDB`` environment variable is set 
1329
then bzr will go into pdb post-mortem mode when an unhandled exception
1330
occurs.
1331
2466.6.3 by Ian Clatworthy
Incorporate feedback from Aaron B. & Alex B.
1332
If you send a SIGQUIT signal to bzr, which can be done by pressing
1333
Ctrl-\\ on Unix, bzr will go into the debugger immediately.  You can
1334
continue execution by typing ``c``.  This can be disabled if necessary
1335
by setting the environment variable ``BZR_SIGQUIT_PDB=0``.
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
1336
1337
1338
Jargon
1339
======
1340
1341
revno
1342
    Integer identifier for a revision on the main line of a branch.
1343
    Revision 0 is always the null revision; others are 1-based
1344
    indexes into the branch's revision history.
1345
1346
1711.2.95 by John Arbash Meinel
Add HACKING note for the self.outf parameter.
1347
Unicode and Encoding Support
1348
============================
1349
1350
This section discusses various techniques that Bazaar uses to handle
1351
characters that are outside the ASCII set.
1352
1353
``Command.outf``
1354
----------------
1355
1356
When a ``Command`` object is created, it is given a member variable
1357
accessible by ``self.outf``.  This is a file-like object, which is bound to
1358
``sys.stdout``, and should be used to write information to the screen,
1359
rather than directly writing to ``sys.stdout`` or calling ``print``.
1360
This file has the ability to translate Unicode objects into the correct
1711.2.96 by John Arbash Meinel
cleanup from suggestions by Robert and Martin
1361
representation, based on the console encoding.  Also, the class attribute
1362
``encoding_type`` will effect how unprintable characters will be
1711.2.95 by John Arbash Meinel
Add HACKING note for the self.outf parameter.
1363
handled.  This parameter can take one of 3 values:
1364
1365
  replace
1711.2.96 by John Arbash Meinel
cleanup from suggestions by Robert and Martin
1366
    Unprintable characters will be represented with a suitable replacement
1367
    marker (typically '?'), and no exception will be raised. This is for
1368
    any command which generates text for the user to review, rather than
1369
    for automated processing.
1711.2.95 by John Arbash Meinel
Add HACKING note for the self.outf parameter.
1370
    For example: ``bzr log`` should not fail if one of the entries has text
1371
    that cannot be displayed.
1372
  
1373
  strict
2063.3.1 by wang
fix typos
1374
    Attempting to print an unprintable character will cause a UnicodeError.
1711.2.95 by John Arbash Meinel
Add HACKING note for the self.outf parameter.
1375
    This is for commands that are intended more as scripting support, rather
1376
    than plain user review.
1377
    For exampl: ``bzr ls`` is designed to be used with shell scripting. One
1378
    use would be ``bzr ls --null --unknows | xargs -0 rm``.  If ``bzr``
1379
    printed a filename with a '?', the wrong file could be deleted. (At the
1380
    very least, the correct file would not be deleted). An error is used to
1381
    indicate that the requested action could not be performed.
1382
  
1383
  exact
1384
    Do not attempt to automatically convert Unicode strings. This is used
1385
    for commands that must handle conversion themselves.
1386
    For example: ``bzr diff`` needs to translate Unicode paths, but should
1387
    not change the exact text of the contents of the files.
1388
1389
1390
``bzrlib.urlutils.unescape_for_display``
1391
----------------------------------------
1392
1393
Because Transports work in URLs (as defined earlier), printing the raw URL
1394
to the user is usually less than optimal. Characters outside the standard
1395
set are printed as escapes, rather than the real character, and local
1396
paths would be printed as ``file://`` urls. The function
1397
``unescape_for_display`` attempts to unescape a URL, such that anything
1398
that cannot be printed in the current encoding stays an escaped URL, but
1399
valid characters are generated where possible.
1400
1401
2405.2.2 by Andrew Bennetts
Add a brief section on portability to HACKING.
1402
Portability Tips
1403
================
1404
1405
The ``bzrlib.osutils`` module has many useful helper functions, including
1406
some more portable variants of functions in the standard library.
1407
1408
In particular, don't use ``shutil.rmtree`` unless it's acceptable for it
1409
to fail on Windows if some files are readonly or still open elsewhere.
1410
Use ``bzrlib.osutils.rmtree`` instead.
1411
1412
1739.1.2 by Robert Collins
More pyrex finesse, documentation.
1413
C Extension Modules
1414
===================
1415
1416
We write some extensions in C using pyrex. We design these to work in
1417
three scenarios:
2449.1.1 by Alexander Belchenko
fix RSTX wrong formatting in HACKING
1418
1739.1.2 by Robert Collins
More pyrex finesse, documentation.
1419
 * User with no C compiler
1420
 * User with C compiler
1421
 * Developers
1422
1423
The recommended way to install bzr is to have a C compiler so that the
1424
extensions can be built, but if no C compiler is present, the pure python
1425
versions we supply will work, though more slowly.
1426
1427
For developers we recommend that pyrex be installed, so that the C
1428
extensions can be changed if needed.
1429
1430
For the C extensions, the extension module should always match the
1431
original python one in all respects (modulo speed). This should be
1432
maintained over time.
1433
1434
To create an extension, add rules to setup.py for building it with pyrex,
1435
and with distutils. Now start with an empty .pyx file. At the top add
1436
"include 'yourmodule.py'". This will import the contents of foo.py into this 
1437
file at build time - remember that only one module will be loaded at
1438
runtime. Now you can subclass classes, or replace functions, and only your
1439
changes need to be present in the .pyx file.
1440
1441
Note that pyrex does not support all 2.4 programming idioms, so some
1442
syntax changes may be required. I.e. 
2449.1.1 by Alexander Belchenko
fix RSTX wrong formatting in HACKING
1443
1739.1.2 by Robert Collins
More pyrex finesse, documentation.
1444
 - 'from foo import (bar, gam)' needs to change to not use the brackets. 
1445
 - 'import foo.bar as bar' needs to be 'import foo.bar; bar = foo.bar' 
2449.1.1 by Alexander Belchenko
fix RSTX wrong formatting in HACKING
1446
1739.1.2 by Robert Collins
More pyrex finesse, documentation.
1447
If the changes are too dramatic, consider
1448
maintaining the python code twice - once in the .pyx, and once in the .py,
1449
and no longer including the .py file.
1450
2466.6.1 by Ian Clatworthy
Expand HACKING into Bazaar Developer Guide
1451
1452
Making Installers for OS Windows
1861.2.19 by Alexander Belchenko
HACKING: mention where to get instructions for building windows installers
1453
================================
1861.2.20 by Alexander Belchenko
English
1454
To build a win32 installer, see the instructions on the wiki page:
1861.2.19 by Alexander Belchenko
HACKING: mention where to get instructions for building windows installers
1455
http://bazaar-vcs.org/BzrWin32Installer
1456
1457
2797.1.1 by Ian Clatworthy
Merge Core Developer Hanbook into HACKING
1458
Core Developer Tasks
1459
####################
1460
1461
Overview
1462
========
1463
1464
What is a Core Developer?
1465
-------------------------
1466
1467
While everyone in the Bazaar community is welcome and encouraged to
1468
propose and submit changes, a smaller team is reponsible for pulling those
1469
changes together into a cohesive whole. In addition to the general developer
1470
stuff covered above, "core" developers have responsibility for:
1471
1472
* reviewing changes
1473
* reviewing blueprints
1474
* planning releases
1475
* managing releases.
1476
1477
.. note::
1478
  Removing barriers to community participation is a key reason for adopting
1479
  distributed VCS technology. While DVCS removes many technical barriers,
1480
  a small number of social barriers are often necessary instead.
1481
  By documenting how the above things are done, we hope to
1482
  encourage more people to participate in these activities, keeping the
1483
  differences between core and non-core contributors to a minimum.
1484
1485
1486
The Development Lifecycle
1487
-------------------------
1488
1489
As a rule, Bazaar development follows a 4 week cycle:
1490
1491
* 2 weeks - general changes
1492
* 1 week - feature freeze
1493
* 1 week+ - Release Candidate stabilization
1494
1495
During the FeatureFreeze week, the trunk (bzr.dev) is open in a limited
1496
way: only low risk changes, critical and high priority fixes are accepted
1497
during this time. At the end of FeatureFreeze, a branch is created for the
1498
first Release Candidate and the trunk is reopened for general development
1499
on the *next* release. A week or so later, the final release is packaged
1500
assuming no serious problems were encountered with the one or more Release
1501
Candidates.
1502
1503
.. note::
1504
  There is a one week overlap between the start of one release and
1505
  the end of the previous one.
1506
1507
1508
Communicating and Coordinating
1509
------------------------------
1510
1511
While it has many advantages, one of the challenges of distributed
1512
development is keeping everyone else aware of what you're working on.
1513
There are numerous ways to do this:
1514
1515
#. Assign bugs to yourself in Launchpad
1516
#. Mention it on the mailing list
1517
#. Mention it on IRC
1518
1519
As well as the email notifcations that occur when merge requests are sent
1520
and reviewed, you can keep others informed of where you're spending your
1521
energy by emailing the **bazaar-commits** list implicitly. To do this,
1522
install and configure the Email plugin. One way to do this is add these
1523
configuration settings to your central configuration file (e.g.
1524
``~/.bazaar/bazaar.conf`` on Linux)::
1525
1526
  [DEFAULT]
1527
  email = Joe Smith <joe.smith@internode.on.net>
1528
  smtp_server = mail.internode.on.net:25
1529
1530
Then add these lines for the relevant branches in ``locations.conf``::
1531
1532
  post_commit_to = bazaar-commits@lists.canonical.com
1533
  post_commit_mailer = smtplib
1534
1535
While attending a sprint, RobertCollins' Dbus plugin is useful for the
1536
same reason. See the documentation within the plugin for information on
1537
how to set it up and configure it.
1538
1539
1540
Reviewing Changes
1541
=================
1542
1543
Setting Up Your Workspace for Reviews
1544
-------------------------------------
1545
1546
TODO: Incorporate John Arbash Meinel's detailed email to Ian C on the
1547
numerous ways of setting up integration branches.
1548
1549
1550
The Review Checklist
1551
--------------------
1552
2797.1.2 by Ian Clatworthy
Incorporate review feedback from poolie
1553
See `A Closer Look at the Merge & Review Process`_
1554
for information on the gates used to decide whether code can be merged
1555
or not and details on how review results are recorded and communicated.
1556
1557
1558
The Importance of Timely Reviews
1559
--------------------------------
2797.1.1 by Ian Clatworthy
Merge Core Developer Hanbook into HACKING
1560
1561
Good reviews do take time. They also regularly require a solid
1562
understanding of the overall code base. In practice, this means a small
1563
number of people often have a large review burden - with knowledge comes
1564
responsibility. No one like their merge requests sitting in a queue going
1565
nowhere, so reviewing sooner rather than later is strongly encouraged.
1566
1567
1568
Submitting Changes
1569
==================
1570
1571
An Overview of PQM
1572
------------------
1573
1574
Of the many workflows supported by Bazaar, the one adopted for Bazaar
1575
development itself is known as "Decentralized with automatic gatekeeper".
1576
To repeat the explanation of this given on
1577
http://bazaar-vcs.org/Workflows:
1578
1579
.. pull-quote::
1580
  In this workflow, each developer has their own branch or
1581
  branches, plus read-only access to the mainline. A software gatekeeper
1582
  (e.g. PQM) has commit rights to the main branch. When a developer wants
1583
  their work merged, they request the gatekeeper to merge it. The gatekeeper
1584
  does a merge, a compile, and runs the test suite. If the code passes, it
1585
  is merged into the mainline.
1586
1587
In a nutshell, here's the overall submission process:
1588
1589
#. get your work ready (including review except for trivial changes)
1590
#. push to a public location
1591
#. ask PQM to merge from that location
1592
1593
.. note::
1594
  At present, PQM always takes the changes to merge from a branch
1595
  at a URL that can be read by it. For Bazaar, that means a public,
1596
  typically http, URL.
1597
1598
As a result, the following things are needed to use PQM for submissions:
1599
1600
#. A publicly available web server
1601
#. Your OpenPGP key registered with PQM (contact RobertCollins for this)
1602
#. The PQM plugin installed and configured (not strictly required but
1603
   highly recommended).
1604
1605
1606
Selecting a Public Branch Location
1607
----------------------------------
1608
1609
If you don't have your own web server running, branches can always be
1610
pushed to Launchpad. Here's the process for doing that:
1611
1612
Depending on your location throughout the world and the size of your
1613
repository though, it is often quicker to use an alternative public
1614
location to Launchpad, particularly if you can set up your own repo and
1615
push into that. By using an existing repo, push only needs to send the
1616
changes, instead of the complete repository every time. Note that it is
1617
easy to register branches in other locations with Launchpad so no benefits
1618
are lost by going this way.
1619
1620
.. note::
1621
  For Canonical staff, http://people.ubuntu.com/~<user>/ is one
1622
  suggestion for public http branches. Contact your manager for information
1623
  on accessing this system if required.
1624
1625
It should also be noted that best practice in this area is subject to
1626
change as things evolve. For example, once the Bazaar smart server on
1627
Launchpad supports server-side branching, the performance situation will
1628
be very different to what it is now (Jun 2007).
1629
1630
1631
Configuring the PQM Plug-In
1632
---------------------------
1633
1634
While not strictly required, the PQM plugin automates a few things and
1635
reduces the chance of error. Before looking at the plugin, it helps to
1636
understand  a little more how PQM operates. Basically, PQM requires an
1637
email indicating what you want it to do. The email typically looks like
1638
this::
1639
1640
  star-merge source-branch target-branch
1641
1642
For example::
1643
1644
  star-merge http://bzr.arbash-meinel.com/branches/bzr/jam-integration http://bazaar-vcs.org/bzr/bzr.dev
1645
1646
Note that the command needs to be on one line. The subject of the email
1647
will be used for the commit message. The email also needs to be ``gpg``
1648
signed with a key that PQM accepts.
1649
1650
The advantages of using the PQM plugin are:
1651
1652
#. You can use the config policies to make it easy to set up public
1653
   branches, so you don't have to ever type the full paths you want to merge
1654
   from or into.
1655
1656
#. It checks to make sure the public branch last revision matches the
1657
   local last revision so you are submitting what you think you are.
1658
1659
#. It uses the same public_branch and smtp sending settings as bzr-email,
1660
   so if you have one set up, you have the other mostly set up.
1661
1662
#. Thunderbird refuses to not wrap lines, and request lines are usually
1663
   pretty long (you have 2 long URLs in there).
1664
1665
Here are sample configuration settings for the PQM plugin. Here are the
1666
lines in bazaar.conf::
1667
1668
  [DEFAULT]
1669
  email = Joe Smith <joe.smith@internode.on.net>
1670
  smtp_server=mail.internode.on.net:25
1671
1672
And here are the lines in ``locations.conf`` (or ``branch.conf`` for
1673
dirstate-tags branches)::
1674
1675
  [/home/joe/bzr/my-integration]
1676
  push_location = sftp://joe-smith@bazaar.launchpad.net/%7Ejoe-smith/bzr/my-integration/
1677
  push_location:policy = norecurse
1678
  public_branch = http://bazaar.launchpad.net/~joe-smith/bzr/my-integration/
1679
  public_branch:policy = appendpath
1680
  pqm_email = Bazaar PQM <pqm@bazaar-vcs.org>
1681
  pqm_branch = http://bazaar-vcs.org/bzr/bzr.dev
1682
1683
Note that the push settings will be added by the first ``push`` on
1684
a branch. Indeed the preferred way to generate the lines above is to use
1685
``push`` with an argument, then copy-and-paste the other lines into
1686
the relevant file.
1687
1688
1689
Submitting a Change
1690
-------------------
1691
1692
Here is one possible recipe once the above environment is set up:
1693
1694
#. pull bzr.dev => my-integration
1695
#. merge patch => my-integration
1696
#. fix up any final merge conflicts (NEWS being the big killer here).
1697
#. commit
1698
#. push
1699
#. pqm-submit
1700
1701
.. note::
1702
  The ``push`` step is not required if ``my-integration`` is a checkout of
1703
  a public branch.
1704
1705
  Because of defaults, you can type a single message into commit and
1706
  pqm-commit will reuse that.
1707
1708
1709
Tracking Change Acceptance
1710
--------------------------
1711
1712
The web interface to PQM is https://pqm.bazaar-vcs.org/. After submitting
1713
a change, you can visit this URL to confirm it was received and placed in
1714
PQM's queue.
1715
1716
When PQM completes processing a change, an email is sent to you with the
1717
results.
1718
1719
1720
Reviewing Blueprints
1721
====================
1722
1723
Blueprint Tracking Using Launchpad
1724
----------------------------------
1725
1726
New features typically require a fair amount of discussion, design and
1727
debate. For Bazaar, that information is often captured in a so-called
1728
"blueprint" on our Wiki. Overall tracking of blueprints and their status
1729
is done using Launchpad's relevant tracker,
1730
https://blueprints.launchpad.net/bzr/. Once a blueprint for ready for
1731
review, please announce it on the mailing list.
1732
1733
Alternatively, send an email begining with [RFC] with the proposal to the
1734
list. In some cases, you may wish to attach proposed code  or a proposed
1735
developer document if that best communicates the idea. Debate can then
1736
proceed using the normal merge review processes.
1737
1738
1739
Recording Blueprint Review Feedback
1740
-----------------------------------
1741
1742
Unlike its Bug Tracker, Launchpad's Blueprint Tracker doesn't currently
1743
(Jun 2007) support a chronological list of comment responses. Review
1744
feedback can either be recorded on the Wiki hosting the blueprints or by
1745
using Launchpad's whiteboard feature.
1746
1747
1748
Planning Releases
1749
=================
1750
1751
Roadmaps
1752
--------
1753
1754
As the two senior developers, Martin Pool and Robert Collins coordinate
1755
the overall Bazaar product development roadmap. Core developers provide
1756
input and review into this, particularly during sprints. It's totally
1757
expected that community members ought to be working on things that
1758
interest them the most. The roadmap is valuable though because it provides
1759
context for understanding where the product is going as a whole and why.
1760
1761
1762
Using Releases and Milestones in Launchpad
1763
------------------------------------------
1764
1765
TODO ... (Exact policies still under discussion)
1766
1767
1768
Bug Triage
1769
----------
1770
1771
Keeping on top of bugs reported is an important part of ongoing release
1772
planning. Everyone in the community is welcome and encouraged to raise
1773
bugs, confirm bugs raised by others, and nominate a priority. Practically
1774
though, a good percentage of bug triage is often done by the core
1775
developers, partially because of their depth of product knowledge.
1776
1777
With respect to bug triage, core developers are encouraged to play an
1778
active role with particular attention to the following tasks:
1779
1780
* keeping the number of unconfirmed bugs low
1781
* ensuring the priorities are generally right (everything as critical - or
1782
  medium - is meaningless)
1783
* looking out for regressions and turning those around sooner rather than later.
1784
1785
.. note::
1786
  As well as prioritizing bugs and nominating them against a
1787
  target milestone, Launchpad lets core developers offer to mentor others in
1788
  fixing them. Nice.
1789
1790
1791
Managing a Release
1792
==================
1793
1794
Starting a Release
1795
------------------
1796
3092.4.5 by Martin Pool
Improved and reformatted developer documentation on the Bazaar release process.
1797
To start a new release cycle:
1798
1799
#. Send mail to the list with the key dates, who will be the release
1800
   manager, and the main themes or targetted bugs.  Ask people to nominate
1801
   objectives, or point out an high-risk things that are best done early,
1802
   or that interact with other changes.
1803
1804
#. Add a new "series" in Launchpad at <https://launchpad.net/bzr/+addseries>.  There is one 
1805
   series for every *x.y* release.
2797.1.1 by Ian Clatworthy
Merge Core Developer Hanbook into HACKING
1806
1807
Weekly Status Updates
1808
---------------------
1809
1810
TODO: Things to cover:
1811
1812
* Early communication to downstream teams (e.g. Launchpad) about changes in dependencies.
1813
* Reminder re lifecycle and where we're up to right now
1814
* Summary of recent successes and pending work
1815
* Reminder re release objectives
1816
* Reminder re things needing attention, e.g. bug triage, reviews, testing of certain things, etc.
1817
1818
1819
Feature Freeze
1820
--------------
1821
1822
TODO: Get material from http://bazaar-vcs.org/FeatureFreeze.
1823
1824
3092.4.4 by Martin Pool
Move ReleaseChecklist into the developer guide
1825
1826
Making a Release or Release Candidate
1827
-------------------------------------
1828
1829
.. Was previously at http://bazaar-vcs.org/ReleaseChecklist
1830
1831
.. TODO: Still needs more clarity on what's in a RC versus a final
1832
.. release?
1833
3092.4.5 by Martin Pool
Improved and reformatted developer documentation on the Bazaar release process.
1834
.. TODO: Too much of this is manual but could be automated...
1835
3092.4.4 by Martin Pool
Move ReleaseChecklist into the developer guide
1836
This is the procedure for making a new bzr release:
1837
1838
#. If the release is the first candidate, make a new branch in PQM. (Contact RobertCollins for this step).
1839
1840
   Register the branch at https://launchpad.net/products/bzr/+addbranch
1841
1842
#. Run the automatic test suite and any non-automated tests.  (For example, try a download over http; these should eventually be scripted though not automatically run.). Try to have all optional dependencies installed so that there are no tests skipped. Also make sure that you have the c extensions compiled (``make`` or ``python setup.py build_ext -i``).
1843
1844
#. In the release branch, update  ``version_info`` in ``./bzrlib/__init__.py``
1845
1846
#. Add the date and release number to ``./NEWS``.
1847
1848
#. Update the release number in the README. (It's not there as of 0.15, but please check).
1849
1850
#. Commit these changes to the release branch, using a command like::
1851
    
1852
     bzr commit -m "(jam) Release 0.12rc1." 
1853
   
1854
   The diff before you commit will be something like::
1855
1856
       === modified file 'NEWS'
1857
       --- NEWS        2006-10-23 13:11:17 +0000
1858
       +++ NEWS        2006-10-23 22:50:50 +0000
1859
       @@ -1,4 +1,4 @@
1860
       -IN DEVELOPMENT
1861
       +bzr 0.12rc1  2006-10-23
1862
1863
          IMPROVEMENTS:
1864
1865
1866
       === modified file 'bzrlib/__init__.py'
1867
       --- bzrlib/__init__.py  2006-10-16 01:47:43 +0000
1868
       +++ bzrlib/__init__.py  2006-10-23 22:49:46 +0000
1869
       @@ -35,7 +35,7 @@
1870
        # Python version 2.0 is (2, 0, 0, 'final', 0)."  Additionally we use a
1871
        # releaselevel of 'dev' for unreleased under-development code.
1872
1873
       -version_info = (0, 12, 0, 'dev', 0)
1874
       +version_info = (0, 12, 0, 'candidate', 1)
1875
1876
        if version_info[3] == 'final':
1877
            version_string = '%d.%d.%d' % version_info[:3]
1878
1879
#. Send the changes to PQM, to update the official master branch.
1880
1881
#. When PQM succeeds, pull down the master release branch.
1882
1883
#. Merge the release branch back into the trunk.  Check that changes in NEWS were merged into the right sections.  If it's not already done, advance the version number in bzr and bzrlib/__init__.py Submit this back into pqm for bzr.dev.
1884
1885
#. Make a distribution directory by running e.g. ``bzr export /tmp/bzr-<version>/`` in the working directory.
1886
1887
#. Run make in /tmp/bzr-<version>. This creates the extensions from the pyrex source.
1888
1889
#. Run the test suite in the distribution directory
1890
1891
#. Run ``setup.py install`` --root=prefix to do a test install into your system directory, home directory, or some other prefix.  Check the install worked and that the installed version is usable. (run the bzr script from the installed path with PYTHONPATH set to the site-packages directory it created). i.e. ::
1892
1893
    python setup.py install --root=installed
1894
    PYTHONPATH=installed/usr/lib/python2.4/site-packages installed/usr/bin/bzr
1895
1896
#. Clean the tree to get rid of .pyc files etc: make clean && rm -rf build && rm bzrlib/_*.c bzrlib/_*.so
1897
1898
#. Generate the reference documentation in text format: make doc/en/user-reference/bzr_man.txt.
1899
1900
#. Change back to your original branch and then run: make clean && make to create the compiled pyrex extensions.  You then need to copy the .c files over to the exported directory. 
1901
   
1902
   ``find . -name "*.c"`` will tell you which files you need.
1903
1904
#. Create the release tarball::
1905
   
1906
     cd /tmp && tar czf bzr-<version>.tar.gz bzr-<version>
1907
3092.4.5 by Martin Pool
Improved and reformatted developer documentation on the Bazaar release process.
1908
#. Sign the tarball with e.g. ``gpg --detach-sign -a bzr-0.10rc1.tar.gz``
1909
1910
1911
Publishing the release
1912
----------------------
1913
1914
Now you have the releasable product.  The next step is making it
1915
available to the world.
1916
1917
#. In <https://launchpad.net/bzr/> click the "Release series" for this
1918
   series, to take you to e.g. <https://launchpad.net/bzr/1.1>.  Then
1919
   click "Register a release", and add information about this release.
1920
1921
#. Within that release, upload the source tarball and the GPG signature.
1922
1923
   (These used to also be uploaded to 
1924
   <sftp://escudero.ubuntu.com/srv/bazaar.canonical.com/www/releases/src>
1925
   but that's not accessible to all developers, and gets some mime types
1926
   wrong...)
1927
1928
#. Link from http://bazaar-vcs.org/Download to the tarball and signature.
1929
1930
#. Update http://doc.bazaar-vcs.org/ to have a directory of documentation
1931
   for this release.  (Controlled by the ``update-bzr-docs`` script on
1932
   escudero, and also update the ``latest`` symlink in
1933
   ``/srv/bazaar.canonical.com/doc/``.)
1934
1935
#. Announce on the `Bazaar home page`__
1936
   
1937
 __ http://bazaar-vcs.org/
1938
1939
1940
Announcing the release
1941
----------------------
1942
1943
Now that the release is publicly available, tell people about it.
3092.4.4 by Martin Pool
Move ReleaseChecklist into the developer guide
1944
1945
#. Announce to ``bazaar-announce`` and ``bazaar`` mailing lists. 
1946
   The announce mail will look something like this:
1947
   
1948
    | Subject: bzr 0.11 release candidate 1
1949
    | 
1950
    | INTRO HERE. Mention the release number and date, and why the release. (i.e. release candidate for testing, final release of a version, backport/bugfix etc).
1951
    | 
1952
    | Tarballs:
1953
    | http://bazaar-vcs.org/releases/src/bzr-VERSION.tar.gz
1954
    | and GPG signature:
1955
    | http://bazaar-vcs.org/releases/src/bzr-VERSION.tar.gz.sig
1956
    | 
1957
    | DESCRIBE-CHANGES-IN-OVERVIEW-HERE
1958
    | 
1959
    | DESCRIBE-when the next release will be (if there is another - i.e. this is a release candidate)
1960
    | 
1961
    | Many thanks to all the contributors to this release! I've included the
1962
    | contents of NEWS for VERSION below:
1963
3092.4.5 by Martin Pool
Improved and reformatted developer documentation on the Bazaar release process.
1964
   To generate the data from NEWS, just copy and paste the relevant news section and clean it up as appropriate. The main clean-up task is to confirm that all major changes are indeed covered. This can be done by running ``bzr log`` back to the point when the branch was opened and cross checking the changes against the NEWS entries.
1965
1966
   (RC announcements should remind plugin maintainers to update their plugins.)
1967
1968
     * For point releases (i.e. a release candidate, or an incremental fix to a released version) take everything in the relevant NEWS secion : for 0.11rc2 take everything in NEWS from the bzr 0.11rc2 line to the bzr 0.11rc1 line further down.
1969
1970
     * For major releases (i.e. 0.11, 0.12 etc), take all the combined NEWS sections from within that version: for 0.11 take all of the 0.11 specific section, plus 0.11rc2, plus 0.11rc1 etc.
3092.4.4 by Martin Pool
Move ReleaseChecklist into the developer guide
1971
1972
#. Update the `news side menu`__ -- this currently requires downloading the file, editing it, deleting it, and uploading a replacement.
1973
3092.4.5 by Martin Pool
Improved and reformatted developer documentation on the Bazaar release process.
1974
   __ http://bazaar-vcs.org/site/menu?action=AttachFile&do=view&target=news.html
3092.4.4 by Martin Pool
Move ReleaseChecklist into the developer guide
1975
1976
#. Update the IRC channel topic. Use the ``/topic`` command to do this, ensuring the new topic text keeps the project name, web site link, etc.
1977
1978
#. Announce on http://freshmeat.net/projects/bzr/
1979
   
1980
   This should be done for both release candidates and final releases. If you do not have a Freshmeat account yet, ask one of the existing admins.
1981
1982
#. Update http://en.wikipedia.org/wiki/Bzr -- this should be done for final releases but not Release Candidates.
1983
1984
#. Package maintainers should update packages when they see the
1985
   announcement.
1986
1987
#. Blog about it.
1988
1989
#. Post to http://mail.python.org/mailman/listinfo/python-announce-list for major releases
1990
3092.4.5 by Martin Pool
Improved and reformatted developer documentation on the Bazaar release process.
1991
#. Update the python package index: <http://pypi.python.org/pypi/bzr> - best
1992
   done by running ::
1993
1994
       python setup.py register
1995
1996
   Remember to check the results afterwards.
3092.4.4 by Martin Pool
Move ReleaseChecklist into the developer guide
1997
1998
1999
Making Win32 installers
2000
-----------------------
2001
3092.4.5 by Martin Pool
Improved and reformatted developer documentation on the Bazaar release process.
2002
**XXX:** This information is now probably obsolete, as Alexander uploads
2003
direct to Launchpad.  --mbp 20080116
2004
3092.4.4 by Martin Pool
Move ReleaseChecklist into the developer guide
2005
Alexander Belchenko has been very good about getting packaged installers compiled (see Win32ReleaseChecklist for details). He generally e-mails John Arbash Meinel when they are ready. This is just a brief checklist of what needs to be done.
2006
2007
#. Download and verify the sha1 sums and gpg signatures. Frequently the sha1 files are in dos mode, and need to be converted to unix mode (strip off the trailing ``\r``) before they veryify correctly.
2008
3092.4.5 by Martin Pool
Improved and reformatted developer documentation on the Bazaar release process.
2009
#. Upload to the Launchpad page for this release.
2010
3092.4.4 by Martin Pool
Move ReleaseChecklist into the developer guide
2011
#. Upload to escudero (to the b.c.c/www/releases/win32 directory) using sftp, lftp or rsync
2012
2013
#. Cat the contents of the .sha1 files into the SHA1SUM.
2014
2015
#. Update the SHA1SUM and MD5SUM files using something like ``md5sum bzr-0.14.0.win32.exe >> MD5SUM``. Make sure you use append (>>) rather than overwrite (>).
2016
2017
#. Verify once again that everything is correct with ``sha1sum -c SHA1SUM`` and ``md5sum -c MD5SUM``.
2018
2019
#. Update ``.htaccess`` so that the 'bzr-latest.win32.exe' links point to the latest release. This is not done for candidate releases, only for final releases. (example: bzr-0.14.0, but not bzr-0.14.0rc1).
2020
2021
#. Make sure these urls work as expected:
2022
2023
   http://bazaar-vcs.org/releases/win32/bzr-latest.win32-py2.5.exe
2024
2025
   http://bazaar-vcs.org/releases/win32/bzr-latest.win32-py2.5.exe.asc
2026
2027
   http://bazaar-vcs.org/releases/win32/bzr-latest.win32-py2.4.exe
2028
2029
   http://bazaar-vcs.org/releases/win32/bzr-latest.win32-py2.4.exe.asc
2030
2031
   http://bazaar-vcs.org/releases/win32/bzr-setup-latest.exe
2032
2033
   http://bazaar-vcs.org/releases/win32/bzr-setup-latest.exe.asc
2034
   
2035
They should all try to download a file with the correct version number.
2036
2037
#. Update http://bazaar-vcs.org/Download to indicate the newly available versions.
2038
2039
#. Update http://bazaar-vcs.org/WindowsDownloads to have the correct version number as well as the correct sha1sum displayed.
2040
2797.1.1 by Ian Clatworthy
Merge Core Developer Hanbook into HACKING
2041
3314.1.1 by Martin Pool
Add Developer's Guide text about PPA builds
2042
The Bazaar PPA archive
2043
----------------------
2044
2045
We build Ubuntu ``.deb`` packages for Bazaar as an important part of the release
2046
process.  These packages are hosted in a `Personal Package Archive (PPA)`__ on
2047
Launchpad, at <https://launchpad.net/~bzr/+archive>.
2048
2049
  __ https://help.launchpad.net/PPAQuickStart
2050
2051
We build packages for every supported Ubuntu release
2052
<https://wiki.ubuntu.com/Releases>.  Packages need no longer be updated
2053
when the release passes end-of-life because all users should have then
2054
update.
2055
2056
The ``debian/`` directory containing the packaging information is kept in
2057
branches on Launchpad, named like 
2058
<https://code.launchpad.net/~bzr/bzrtools/packaging-dapper>
2059
2060
Updating the PPA for a new release
2061
----------------------------------
2062
2063
Preconditions for building these packages:
2064
  
2065
 * You must have a Launchpad account and be a member of the `~bzr`__ team
2066
   
2067
 __ https://edge.launchpad.net/~bzr/+members>
2068
2069
 * You must have a GPG key registered to your Launchpad account.
2070
2071
 * Configure ``dput`` to upload to our PPA with this section in your
2072
   ``~/.dput.cf``::
2073
2074
        [bzr-ppa]
2075
        fqdn = ppa.launchpad.net
2076
        method = ftp
2077
        incoming = ~bzr/ubuntu
2078
        login = anonymous
2079
        allow_unsigned_uploads = 0
2080
2081
 * You need a Ubuntu (or probably Debian) machine, and ::
2082
2083
     sudo apt-get install build-essential devscripts dput
2084
2085
Here is the process; there are some steps which should be automated in
2086
future:
2087
2088
#. You will need a working directory for each supported release, such as
2089
   ``~/bzr/Packaging/dapper``
2090
2091
#. Download the official tarball of the release to e.g. ``~/bzr/Releases``
2092
2093
#. Copy the original tarball into your per-disto directory, then untar it 
2094
   and if necessary rename it::
2095
2096
     cp -l ~/bzr/Releases/bzrtools-1.3.0.tar.gz bzrtools_1.3.0.orig.tar.gz
2097
     tar xfvz bzrtools_1.3.0.orig.tar.gz
2098
     mv bzrtools bzrtools-1.3.0
2099
2100
#. Change into that directory and check out the packaging branch::
2101
2102
     cd bzrtools
2103
     bzr checkout \
2104
       bzr+ssh://bazaar.launchpad.net/~bzr/bzrtools/packaging-dapper \
2105
       debian
2106
2107
#. For Bazaar plugins, change the ``debian/control`` file to express a
2108
   dependency on the correct version of ``bzr``.
2109
2110
   For bzrtools this is typically::
2111
2112
      Build-Depends-Indep: bzr (>= 1.3~), rsync
2113
      Depends: ${python:Depends}, bzr (>= 1.3~), bzr (<< 1.4~), patch
2114
2115
#. Make a new ``debian/changelog`` entry for the new release,
2116
   either by using ``dch`` or just editing the file::
2117
3314.1.2 by Martin Pool
Minor corrections to PPA build process (dato)
2118
     dch -v '1.3.0-1~bazaar1~dapper1' -D dapper
3314.1.1 by Martin Pool
Add Developer's Guide text about PPA builds
2119
3314.1.2 by Martin Pool
Minor corrections to PPA build process (dato)
2120
   dch will default to the distro you're working in and this isn't checked
2121
   against the version number (which is just our conversion).  So make
2122
   sure to specify it.
3314.1.1 by Martin Pool
Add Developer's Guide text about PPA builds
2123
2124
   Make sure you have the correct email address for yourself, version
3360.1.1 by Martin Pool
Fix ReST syntax
2125
   number, and distribution.  It should look something like this::
3314.1.1 by Martin Pool
Add Developer's Guide text about PPA builds
2126
2127
     >  bzrtools (1.3.0-1~bazaar1~dapper1) dapper; urgency=low
2128
     >
2129
     >   * New upstream release.
2130
     >
3360.1.1 by Martin Pool
Fix ReST syntax
2131
     >  -- John Sample <sample@example.com>  Mon, 31 Mar 2008 12:36:27 +1100
3314.1.1 by Martin Pool
Add Developer's Guide text about PPA builds
2132
2133
   If you need to upload the package again to fix a problem, normally you
2134
   should increment the last number in the version number, following the
2135
   distro name.  Make sure not to omit the initial ``-1``, and make sure
2136
   that the distro name in the version is consistent with the target name
2137
   outside the parenthesis.
2138
2139
#. Commit these changes into the packaging branch::
2140
2141
     bzr ci -m '1.3.0-1~bazaar1~dapper1: New upstream release.' debian
2142
2143
#. Build a source package::
2144
3314.1.2 by Martin Pool
Minor corrections to PPA build process (dato)
2145
     debuild -S -sa -i
3314.1.1 by Martin Pool
Add Developer's Guide text about PPA builds
2146
3314.1.2 by Martin Pool
Minor corrections to PPA build process (dato)
2147
   This will create a ``.changes`` file in the per-distro directory,
2148
   and should invoke gpg to sign it with your key.
3314.1.1 by Martin Pool
Add Developer's Guide text about PPA builds
2149
   Check that file is reasonable: it should be uploading to the intended
2150
   distribution, have a .orig file included, and the right version number.
2151
2152
#. Upload into the PPA::
2153
2154
     dput bzr-ppa ../bzrtools__1.3.0-1\~bazaar1\~dapper1_source.changes
2155
2156
   Don't forget the ``bzr-ppa`` component or dput will try to upload into
2157
   the main archive by default.  You can disable this by adding this
2158
   section to your ``.dput.cf``::
2159
2160
     [ubuntu]
2161
     fqdn = SPECIFY.A.PPA.NAME
2162
2163
#. You should soon get an "upload accepted" mail from Launchpad, which
2164
   means that your package is waiting to be built.  You can then track its
2165
   progress in <https://launchpad.net/~bzr/+archive> and
2166
   <https://launchpad.net/~bzr/+archive/+builds>.
2167
2168
2475.2.4 by Martin Pool
HACKING rest fixes from jam
2169
..
2170
   vim: ft=rst tw=74 ai