391
349
test was not run, rather than just returning which makes it look as if it
392
350
was run and passed.
394
Several different cases are distinguished:
397
Generic skip; the only type that was present up to bzr 0.18.
400
The test doesn't apply to the parameters with which it was run.
401
This is typically used when the test is being applied to all
402
implementations of an interface, but some aspects of the interface
403
are optional and not present in particular concrete
404
implementations. (Some tests that should raise this currently
405
either silently return or raise TestSkipped.) Another option is
406
to use more precise parameterization to avoid generating the test
410
**(Not implemented yet)**
411
The test can't be run because of an inherent limitation of the
412
environment, such as not having symlinks or not supporting
416
The test can't be run because a dependency (typically a Python
417
library) is not available in the test environment. These
418
are in general things that the person running the test could fix
419
by installing the library. It's OK if some of these occur when
420
an end user runs the tests or if we're specifically testing in a
421
limited environment, but a full test should never see them.
424
The test exists but is known to fail, for example because the
425
code to fix it hasn't been run yet. Raising this allows
426
you to distinguish these failures from the ones that are not
427
expected to fail. This could be conditionally raised if something
428
is broken on some platforms but not on others.
430
We plan to support three modes for running the test suite to control the
431
interpretation of these results. Strict mode is for use in situations
432
like merges to the mainline and releases where we want to make sure that
433
everything that can be tested has been tested. Lax mode is for use by
434
developers who want to temporarily tolerate some known failures. The
435
default behaviour is obtained by ``bzr selftest`` with no options, and
436
also (if possible) by running under another unittest harness.
438
======================= ======= ======= ========
439
result strict default lax
440
======================= ======= ======= ========
441
TestSkipped pass pass pass
442
TestNotApplicable pass pass pass
443
TestPlatformLimit pass pass pass
444
TestDependencyMissing fail pass pass
445
KnownFailure fail pass pass
446
======================= ======= ======= ========
449
Test feature dependencies
450
-------------------------
452
Rather than manually checking the environment in each test, a test class
453
can declare its dependence on some test features. The feature objects are
454
checked only once for each run of the whole test suite.
456
For historical reasons, as of May 2007 many cases that should depend on
457
features currently raise TestSkipped.)
352
A subtly different case is a test that should run, but can't run in the
353
current environment. This covers tests that can only run in particular
354
operating systems or locales, or that depend on external libraries. Here
355
we want to inform the user that they didn't get full test coverage, but
356
they possibly could if they installed more libraries. These are expressed
357
as a dependency on a feature so we can summarise them, and so that the
358
test for the feature is done only once. (For historical reasons, as of
359
May 2007 many cases that should depend on features currently raise
360
TestSkipped.) The typical use is::
461
362
class TestStrace(TestCaseWithTransport):
463
364
_test_needs_features = [StraceFeature]
465
This means all tests in this class need the feature. The feature itself
366
which means all tests in this class need the feature. The feature itself
466
367
should provide a ``_probe`` method which is called once to determine if
469
These should generally be equivalent to either TestDependencyMissing or
470
sometimes TestPlatformLimit.
512
410
they're displayed or handled.
518
The Python ``warnings`` module is used to indicate a non-fatal code
519
problem. Code that's expected to raise a warning can be tested through
522
The test suite can be run with ``-Werror`` to check no unexpected errors
525
However, warnings should be used with discretion. It's not an appropriate
526
way to give messages to the user, because the warning is normally shown
527
only once per source line that causes the problem. You should also think
528
about whether the warning is serious enought that it should be visible to
529
users who may not be able to fix it.
532
Interface implementation testing and test scenarios
533
---------------------------------------------------
535
There are several cases in Bazaar of multiple implementations of a common
536
conceptual interface. ("Conceptual" because
537
it's not necessary for all the implementations to share a base class,
538
though they often do.) Examples include transports and the working tree,
539
branch and repository classes.
541
In these cases we want to make sure that every implementation correctly
542
fulfils the interface requirements. For example, every Transport should
543
support the ``has()`` and ``get()`` and ``clone()`` methods. We have a
544
sub-suite of tests in ``test_transport_implementations``. (Most
545
per-implementation tests are in submodules of ``bzrlib.tests``, but not
546
the transport tests at the moment.)
548
These tests are repeated for each registered Transport, by generating a
549
new TestCase instance for the cross product of test methods and transport
550
implementations. As each test runs, it has ``transport_class`` and
551
``transport_server`` set to the class it should test. Most tests don't
552
access these directly, but rather use ``self.get_transport`` which returns
553
a transport of the appropriate type.
555
The goal is to run per-implementation only tests that relate to that
556
particular interface. Sometimes we discover a bug elsewhere that happens
557
with only one particular transport. Once it's isolated, we can consider
558
whether a test should be added for that particular implementation,
559
or for all implementations of the interface.
561
The multiplication of tests for different implementations is normally
562
accomplished by overriding the ``test_suite`` function used to load
563
tests from a module. This function typically loads all the tests,
564
then applies a TestProviderAdapter to them, which generates a longer
565
suite containing all the test variations.
571
Some utilities are provided for generating variations of tests. This can
572
be used for per-implementation tests, or other cases where the same test
573
code needs to run several times on different scenarios.
575
The general approach is to define a class that provides test methods,
576
which depend on attributes of the test object being pre-set with the
577
values to which the test should be applied. The test suite should then
578
also provide a list of scenarios in which to run the tests.
580
Typically ``multiply_tests_from_modules`` should be called from the test
581
module's ``test_suite`` function.
584
413
Essential Domain Classes
585
414
########################
650
479
the form of URL components.
488
We have a commitment to 6 months API stability - any supported symbol in a
489
release of bzr MUST NOT be altered in any way that would result in
490
breaking existing code that uses it. That means that method names,
491
parameter ordering, parameter names, variable and attribute names etc must
492
not be changed without leaving a 'deprecated forwarder' behind. This even
493
applies to modules and classes.
495
If you wish to change the behaviour of a supported API in an incompatible
496
way, you need to change its name as well. For instance, if I add an optional keyword
497
parameter to branch.commit - that's fine. On the other hand, if I add a
498
keyword parameter to branch.commit which is a *required* transaction
499
object, I should rename the API - i.e. to 'branch.commit_transaction'.
501
When renaming such supported API's, be sure to leave a deprecated_method (or
502
_function or ...) behind which forwards to the new API. See the
503
bzrlib.symbol_versioning module for decorators that take care of the
504
details for you - such as updating the docstring, and issuing a warning
505
when the old api is used.
507
For unsupported API's, it does not hurt to follow this discipline, but it's
508
not required. Minimally though, please try to rename things so that
509
callers will at least get an AttributeError rather than weird results.
653
512
Coding Style Guidelines
654
#######################
659
``hasattr`` should not be used because it swallows exceptions including
660
``KeyboardInterrupt``. Instead, say something like ::
662
if getattr(thing, 'name', None) is None
513
=======================
668
515
Please write PEP-8__ compliant code.
670
__ http://www.python.org/peps/pep-0008.html
672
517
One often-missed requirement is that the first line of docstrings
673
518
should be a self-contained one-sentence summary.
675
We use 4 space indents for blocks, and never use tab characters. (In vim,
678
Lines should be no more than 79 characters if at all possible.
679
Lines that continue a long statement may be indented in either of
682
within the parenthesis or other character that opens the block, e.g.::
688
or indented by four spaces::
694
The first is considered clearer by some people; however it can be a bit
695
harder to maintain (e.g. when the method name changes), and it does not
696
work well if the relevant parenthesis is already far to the right. Avoid
699
self.legbone.kneebone.shinbone.toebone.shake_it(one,
705
self.legbone.kneebone.shinbone.toebone.shake_it(one,
711
self.legbone.kneebone.shinbone.toebone.shake_it(
714
For long lists, we like to add a trailing comma and put the closing
715
character on the following line. This makes it easier to add new items in
718
from bzrlib.goo import (
724
There should be spaces between function paramaters, but not between the
725
keyword name and the value::
727
call(1, 3, cheese=quark)
731
;(defface my-invalid-face
732
; '((t (:background "Red" :underline t)))
733
; "Face used to highlight invalid constructs or other uglyties"
736
(defun my-python-mode-hook ()
737
;; setup preferred indentation style.
738
(setq fill-column 79)
739
(setq indent-tabs-mode nil) ; no tabs, never, I will not repeat
740
; (font-lock-add-keywords 'python-mode
741
; '(("^\\s *\t" . 'my-invalid-face) ; Leading tabs
742
; ("[ \t]+$" . 'my-invalid-face) ; Trailing spaces
743
; ("^[ \t]+$" . 'my-invalid-face)); Spaces only
747
(add-hook 'python-mode-hook 'my-python-mode-hook)
749
The lines beginning with ';' are comments. They can be activated
750
if one want to have a strong notice of some tab/space usage
520
__ http://www.python.org/peps/pep-0008.html
757
526
* Imports should be done at the top-level of the file, unless there is
758
527
a strong reason to have them lazily loaded when a particular
908
683
being phased out.
911
Object string representations
912
=============================
914
Python prints objects using their ``__repr__`` method when they are
915
written to logs, exception tracebacks, or the debugger. We want
916
objects to have useful representations to help in determining what went
919
If you add a new class you should generally add a ``__repr__`` method
920
unless there is an adequate method in a parent class. There should be a
923
Representations should typically look like Python constructor syntax, but
924
they don't need to include every value in the object and they don't need
925
to be able to actually execute. They're to be read by humans, not
926
machines. Don't hardcode the classname in the format, so that we get the
927
correct value if the method is inherited by a subclass. If you're
928
printing attributes of the object, including strings, you should normally
929
use ``%r`` syntax (to call their repr in turn).
931
Try to avoid the representation becoming more than one or two lines long.
932
(But balance this against including useful information, and simplicity of
935
Because repr methods are often called when something has already gone
936
wrong, they should be written more defensively than most code. The object
937
may be half-initialized or in some other way in an illegal state. The
938
repr method shouldn't raise an exception, or it may hide the (probably
939
more useful) underlying exception.
945
return '%s(%r)' % (self.__class__.__name__,
948
return 'FooObject(**unprintable**)'
957
We have a commitment to 6 months API stability - any supported symbol in a
958
release of bzr MUST NOT be altered in any way that would result in
959
breaking existing code that uses it. That means that method names,
960
parameter ordering, parameter names, variable and attribute names etc must
961
not be changed without leaving a 'deprecated forwarder' behind. This even
962
applies to modules and classes.
964
If you wish to change the behaviour of a supported API in an incompatible
965
way, you need to change its name as well. For instance, if I add an optional keyword
966
parameter to branch.commit - that's fine. On the other hand, if I add a
967
keyword parameter to branch.commit which is a *required* transaction
968
object, I should rename the API - i.e. to 'branch.commit_transaction'.
970
When renaming such supported API's, be sure to leave a deprecated_method (or
971
_function or ...) behind which forwards to the new API. See the
972
bzrlib.symbol_versioning module for decorators that take care of the
973
details for you - such as updating the docstring, and issuing a warning
974
when the old api is used.
976
For unsupported API's, it does not hurt to follow this discipline, but it's
977
not required. Minimally though, please try to rename things so that
978
callers will at least get an AttributeError rather than weird results.
981
Deprecation decorators
982
----------------------
984
``bzrlib.symbol_versioning`` provides decorators that can be attached to
985
methods, functions, and other interfaces to indicate that they should no
986
longer be used. For example::
988
@deprecated_method(deprecated_in((0, 1, 4)))
990
return self._new_foo()
992
To deprecate a static method you must call ``deprecated_function``
993
(**not** method), after the staticmethod call::
996
@deprecated_function(deprecated_in((0, 1, 4)))
997
def create_repository(base, shared=False, format=None):
999
When you deprecate an API, you should not just delete its tests, because
1000
then we might introduce bugs in them. If the API is still present at all,
1001
it should still work. The basic approach is to use
1002
``TestCase.applyDeprecated`` which in one step checks that the API gives
1003
the expected deprecation message, and also returns the real result from
1004
the method, so that tests can keep running.
1006
Deprecation warnings will be suppressed for final releases, but not for
1007
development versions or release candidates, or when running ``bzr
1008
selftest``. This gives developers information about whether their code is
1009
using deprecated functions, but avoids confusing users about things they
1533
1175
http://bazaar-vcs.org/BzrWin32Installer
1536
Core Developer Tasks
1537
####################
1542
What is a Core Developer?
1543
-------------------------
1545
While everyone in the Bazaar community is welcome and encouraged to
1546
propose and submit changes, a smaller team is reponsible for pulling those
1547
changes together into a cohesive whole. In addition to the general developer
1548
stuff covered above, "core" developers have responsibility for:
1551
* reviewing blueprints
1553
* managing releases.
1556
Removing barriers to community participation is a key reason for adopting
1557
distributed VCS technology. While DVCS removes many technical barriers,
1558
a small number of social barriers are often necessary instead.
1559
By documenting how the above things are done, we hope to
1560
encourage more people to participate in these activities, keeping the
1561
differences between core and non-core contributors to a minimum.
1564
The Development Lifecycle
1565
-------------------------
1567
As a rule, Bazaar development follows a 4 week cycle:
1569
* 2 weeks - general changes
1570
* 1 week - feature freeze
1571
* 1 week+ - Release Candidate stabilization
1573
During the FeatureFreeze week, the trunk (bzr.dev) is open in a limited
1574
way: only low risk changes, critical and high priority fixes are accepted
1575
during this time. At the end of FeatureFreeze, a branch is created for the
1576
first Release Candidate and the trunk is reopened for general development
1577
on the *next* release. A week or so later, the final release is packaged
1578
assuming no serious problems were encountered with the one or more Release
1582
There is a one week overlap between the start of one release and
1583
the end of the previous one.
1586
Communicating and Coordinating
1587
------------------------------
1589
While it has many advantages, one of the challenges of distributed
1590
development is keeping everyone else aware of what you're working on.
1591
There are numerous ways to do this:
1593
#. Assign bugs to yourself in Launchpad
1594
#. Mention it on the mailing list
1595
#. Mention it on IRC
1597
As well as the email notifcations that occur when merge requests are sent
1598
and reviewed, you can keep others informed of where you're spending your
1599
energy by emailing the **bazaar-commits** list implicitly. To do this,
1600
install and configure the Email plugin. One way to do this is add these
1601
configuration settings to your central configuration file (e.g.
1602
``~/.bazaar/bazaar.conf`` on Linux)::
1605
email = Joe Smith <joe.smith@internode.on.net>
1606
smtp_server = mail.internode.on.net:25
1608
Then add these lines for the relevant branches in ``locations.conf``::
1610
post_commit_to = bazaar-commits@lists.canonical.com
1611
post_commit_mailer = smtplib
1613
While attending a sprint, RobertCollins' Dbus plugin is useful for the
1614
same reason. See the documentation within the plugin for information on
1615
how to set it up and configure it.
1621
Setting Up Your Workspace for Reviews
1622
-------------------------------------
1624
TODO: Incorporate John Arbash Meinel's detailed email to Ian C on the
1625
numerous ways of setting up integration branches.
1628
The Review Checklist
1629
--------------------
1631
See `A Closer Look at the Merge & Review Process`_
1632
for information on the gates used to decide whether code can be merged
1633
or not and details on how review results are recorded and communicated.
1636
The Importance of Timely Reviews
1637
--------------------------------
1639
Good reviews do take time. They also regularly require a solid
1640
understanding of the overall code base. In practice, this means a small
1641
number of people often have a large review burden - with knowledge comes
1642
responsibility. No one like their merge requests sitting in a queue going
1643
nowhere, so reviewing sooner rather than later is strongly encouraged.
1652
Of the many workflows supported by Bazaar, the one adopted for Bazaar
1653
development itself is known as "Decentralized with automatic gatekeeper".
1654
To repeat the explanation of this given on
1655
http://bazaar-vcs.org/Workflows:
1658
In this workflow, each developer has their own branch or
1659
branches, plus read-only access to the mainline. A software gatekeeper
1660
(e.g. PQM) has commit rights to the main branch. When a developer wants
1661
their work merged, they request the gatekeeper to merge it. The gatekeeper
1662
does a merge, a compile, and runs the test suite. If the code passes, it
1663
is merged into the mainline.
1665
In a nutshell, here's the overall submission process:
1667
#. get your work ready (including review except for trivial changes)
1668
#. push to a public location
1669
#. ask PQM to merge from that location
1672
At present, PQM always takes the changes to merge from a branch
1673
at a URL that can be read by it. For Bazaar, that means a public,
1674
typically http, URL.
1676
As a result, the following things are needed to use PQM for submissions:
1678
#. A publicly available web server
1679
#. Your OpenPGP key registered with PQM (contact RobertCollins for this)
1680
#. The PQM plugin installed and configured (not strictly required but
1681
highly recommended).
1684
Selecting a Public Branch Location
1685
----------------------------------
1687
If you don't have your own web server running, branches can always be
1688
pushed to Launchpad. Here's the process for doing that:
1690
Depending on your location throughout the world and the size of your
1691
repository though, it is often quicker to use an alternative public
1692
location to Launchpad, particularly if you can set up your own repo and
1693
push into that. By using an existing repo, push only needs to send the
1694
changes, instead of the complete repository every time. Note that it is
1695
easy to register branches in other locations with Launchpad so no benefits
1696
are lost by going this way.
1699
For Canonical staff, http://people.ubuntu.com/~<user>/ is one
1700
suggestion for public http branches. Contact your manager for information
1701
on accessing this system if required.
1703
It should also be noted that best practice in this area is subject to
1704
change as things evolve. For example, once the Bazaar smart server on
1705
Launchpad supports server-side branching, the performance situation will
1706
be very different to what it is now (Jun 2007).
1709
Configuring the PQM Plug-In
1710
---------------------------
1712
While not strictly required, the PQM plugin automates a few things and
1713
reduces the chance of error. Before looking at the plugin, it helps to
1714
understand a little more how PQM operates. Basically, PQM requires an
1715
email indicating what you want it to do. The email typically looks like
1718
star-merge source-branch target-branch
1722
star-merge http://bzr.arbash-meinel.com/branches/bzr/jam-integration http://bazaar-vcs.org/bzr/bzr.dev
1724
Note that the command needs to be on one line. The subject of the email
1725
will be used for the commit message. The email also needs to be ``gpg``
1726
signed with a key that PQM accepts.
1728
The advantages of using the PQM plugin are:
1730
#. You can use the config policies to make it easy to set up public
1731
branches, so you don't have to ever type the full paths you want to merge
1734
#. It checks to make sure the public branch last revision matches the
1735
local last revision so you are submitting what you think you are.
1737
#. It uses the same public_branch and smtp sending settings as bzr-email,
1738
so if you have one set up, you have the other mostly set up.
1740
#. Thunderbird refuses to not wrap lines, and request lines are usually
1741
pretty long (you have 2 long URLs in there).
1743
Here are sample configuration settings for the PQM plugin. Here are the
1744
lines in bazaar.conf::
1747
email = Joe Smith <joe.smith@internode.on.net>
1748
smtp_server=mail.internode.on.net:25
1750
And here are the lines in ``locations.conf`` (or ``branch.conf`` for
1751
dirstate-tags branches)::
1753
[/home/joe/bzr/my-integration]
1754
push_location = sftp://joe-smith@bazaar.launchpad.net/%7Ejoe-smith/bzr/my-integration/
1755
push_location:policy = norecurse
1756
public_branch = http://bazaar.launchpad.net/~joe-smith/bzr/my-integration/
1757
public_branch:policy = appendpath
1758
pqm_email = Bazaar PQM <pqm@bazaar-vcs.org>
1759
pqm_branch = http://bazaar-vcs.org/bzr/bzr.dev
1761
Note that the push settings will be added by the first ``push`` on
1762
a branch. Indeed the preferred way to generate the lines above is to use
1763
``push`` with an argument, then copy-and-paste the other lines into
1770
Here is one possible recipe once the above environment is set up:
1772
#. pull bzr.dev => my-integration
1773
#. merge patch => my-integration
1774
#. fix up any final merge conflicts (NEWS being the big killer here).
1780
The ``push`` step is not required if ``my-integration`` is a checkout of
1783
Because of defaults, you can type a single message into commit and
1784
pqm-commit will reuse that.
1787
Tracking Change Acceptance
1788
--------------------------
1790
The web interface to PQM is https://pqm.bazaar-vcs.org/. After submitting
1791
a change, you can visit this URL to confirm it was received and placed in
1794
When PQM completes processing a change, an email is sent to you with the
1798
Reviewing Blueprints
1799
====================
1801
Blueprint Tracking Using Launchpad
1802
----------------------------------
1804
New features typically require a fair amount of discussion, design and
1805
debate. For Bazaar, that information is often captured in a so-called
1806
"blueprint" on our Wiki. Overall tracking of blueprints and their status
1807
is done using Launchpad's relevant tracker,
1808
https://blueprints.launchpad.net/bzr/. Once a blueprint for ready for
1809
review, please announce it on the mailing list.
1811
Alternatively, send an email begining with [RFC] with the proposal to the
1812
list. In some cases, you may wish to attach proposed code or a proposed
1813
developer document if that best communicates the idea. Debate can then
1814
proceed using the normal merge review processes.
1817
Recording Blueprint Review Feedback
1818
-----------------------------------
1820
Unlike its Bug Tracker, Launchpad's Blueprint Tracker doesn't currently
1821
(Jun 2007) support a chronological list of comment responses. Review
1822
feedback can either be recorded on the Wiki hosting the blueprints or by
1823
using Launchpad's whiteboard feature.
1832
As the two senior developers, Martin Pool and Robert Collins coordinate
1833
the overall Bazaar product development roadmap. Core developers provide
1834
input and review into this, particularly during sprints. It's totally
1835
expected that community members ought to be working on things that
1836
interest them the most. The roadmap is valuable though because it provides
1837
context for understanding where the product is going as a whole and why.
1840
Using Releases and Milestones in Launchpad
1841
------------------------------------------
1843
TODO ... (Exact policies still under discussion)
1849
Keeping on top of bugs reported is an important part of ongoing release
1850
planning. Everyone in the community is welcome and encouraged to raise
1851
bugs, confirm bugs raised by others, and nominate a priority. Practically
1852
though, a good percentage of bug triage is often done by the core
1853
developers, partially because of their depth of product knowledge.
1855
With respect to bug triage, core developers are encouraged to play an
1856
active role with particular attention to the following tasks:
1858
* keeping the number of unconfirmed bugs low
1859
* ensuring the priorities are generally right (everything as critical - or
1860
medium - is meaningless)
1861
* looking out for regressions and turning those around sooner rather than later.
1864
As well as prioritizing bugs and nominating them against a
1865
target milestone, Launchpad lets core developers offer to mentor others in
1870
1179
vim: ft=rst tw=74 ai
added
removed
doc/developers/HACKING.txt
