Update coverage to 5.0

[pyup-bot]

This PR updates coverage from 4.0.3 to 5.0.

Changelog

5.0

--------------------------

Nothing new beyond 5.0b2.


.. _changes_50b2:

5.0b2

----------------------------

- An experimental ``[run] relative_files`` setting tells coverage to store
relative file names in the data file. This makes it easier to run tests in
one (or many) environments, and then report in another.  It has not had much
real-world testing, so it may change in incompatible ways in the future.

- When constructing a :class:`coverage.Coverage` object, `data_file` can be
specified as None to prevent writing any data file at all.  In previous
versions, an explicit `data_file=None` argument would use the default of
".coverage". Fixes `issue 871`_.

- Python files run with ``-m`` now have ``__spec__`` defined properly.  This
fixes `issue 745`_ (about not being able to run unittest tests that spawn
subprocesses), and `issue 838`_, which described the problem directly.

- The ``[paths]`` configuration section is now ordered. If you specify more
than one list of patterns, the first one that matches will be used.  Fixes
`issue 649`_.

- The :func:`.coverage.numbits.register_sqlite_functions` function now also
registers `numbits_to_nums` for use in SQLite queries.  Thanks, Simon
Willison.

- Python 3.9a1 is supported.

- Coverage.py has a mascot: :ref:`Sleepy Snake <sleepy>`.

.. _issue 649: https://github.com/nedbat/coveragepy/issues/649
.. _issue 745: https://github.com/nedbat/coveragepy/issues/745
.. _issue 838: https://github.com/nedbat/coveragepy/issues/838
.. _issue 871: https://github.com/nedbat/coveragepy/issues/871


.. _changes_50b1:

5.0b1

----------------------------

- The HTML and textual reports now have a ``--skip-empty`` option that skips
files with no statements, notably ``__init__.py`` files.  Thanks, Reya B.

- Configuration can now be read from `TOML`_ files.  This requires installing
coverage.py with the ``[toml]`` extra.  The standard "pyproject.toml" file
will be read automatically if no other configuration file is found, with
settings in the ``[tool.coverage.]`` namespace.  Thanks to Frazer McLean for
implementation and persistence.  Finishes `issue 664`_.

- The ``[run] note`` setting has been deprecated. Using it will result in a
warning, and the note will not be written to the data file.  The
corresponding :class:`.CoverageData` methods have been removed.

- The HTML report has been reimplemented (no more table around the source
code). This allowed for a better presentation of the context information,
hopefully resolving `issue 855`_.

- Added sqlite3 module version information to ``coverage debug sys`` output.

- Asking the HTML report to show contexts (``[html] show_contexts=True`` or
``coverage html --show-contexts``) will issue a warning if there were no
contexts measured (`issue 851`_).

.. _TOML: https://github.com/toml-lang/tomlreadme
.. _issue 664: https://github.com/nedbat/coveragepy/issues/664
.. _issue 851: https://github.com/nedbat/coveragepy/issues/851
.. _issue 855: https://github.com/nedbat/coveragepy/issues/855


.. _changes_50a8:

5.0a8

----------------------------

- The :class:`.CoverageData` API has changed how queries are limited to
specific contexts.  Now you use :meth:`.CoverageData.set_query_context` to
set a single exact-match string, or :meth:`.CoverageData.set_query_contexts`
to set a list of regular expressions to match contexts.  This changes the
command-line ``--contexts`` option to use regular expressions instead of
filename-style wildcards.


.. _changes_50a7:

5.0a7

----------------------------

- Data can now be "reported" in JSON format, for programmatic use, as requested
in `issue 720`_.  The new ``coverage json`` command writes raw and summarized
data to a JSON file.  Thanks, Matt Bachmann.

- Dynamic contexts are now supported in the Python tracer, which is important
for PyPy users.  Closes `issue 846`_.

- The compact line number representation introduced in 5.0a6 is called a
"numbits."  The :mod:`coverage.numbits` module provides functions for working
with them.

- The reporting methods used to permanently apply their arguments to the
configuration of the Coverage object.  Now they no longer do.  The arguments
affect the operation of the method, but do not persist.

- A class named "test_something" no longer confuses the ``test_function``
dynamic context setting.  Fixes `issue 829`_.

- Fixed an unusual tokenizing issue with backslashes in comments.  Fixes
`issue 822`_.

- ``debug=plugin`` didn't properly support configuration or dynamic context
plugins, but now it does, closing `issue 834`_.

.. _issue 720: https://github.com/nedbat/coveragepy/issues/720
.. _issue 822: https://github.com/nedbat/coveragepy/issues/822
.. _issue 834: https://github.com/nedbat/coveragepy/issues/834
.. _issue 829: https://github.com/nedbat/coveragepy/issues/829
.. _issue 846: https://github.com/nedbat/coveragepy/issues/846


.. _changes_50a6:

5.0a6

----------------------------

- Reporting on contexts. Big thanks to Stephan Richter and Albertas Agejevas
for the contribution.

- The ``--contexts`` option is available on the ``report`` and ``html``
 commands.  It's a comma-separated list of shell-style wildcards, selecting
 the contexts to report on.  Only contexts matching one of the wildcards
 will be included in the report.

- The ``--show-contexts`` option for the ``html`` command adds context
 information to each covered line.  Hovering over the "ctx" marker at the
 end of the line reveals a list of the contexts that covered the line.

- Database changes:

- Line numbers are now stored in a much more compact way.  For each file and
 context, a single binary string is stored with a bit per line number.  This
 greatly improves memory use, but makes ad-hoc use difficult.

- Dynamic contexts with no data are no longer written to the database.

- SQLite data storage is now faster.  There's no longer a reason to keep the
 JSON data file code, so it has been removed.

- Changes to the :class:`.CoverageData` interface:

- The new :meth:`.CoverageData.dumps` method serializes the data to a string,
 and a corresponding :meth:`.CoverageData.loads` method reconstitutes this
 data.  The format of the data string is subject to change at any time, and
 so should only be used between two installations of the same version of
 coverage.py.

- The :meth:`CoverageData constructor<.CoverageData.__init__>` has a new
 argument, `no_disk` (default: False).  Setting it to True prevents writing
 any data to the disk.  This is useful for transient data objects.

- Added the classmethod :meth:`.Coverage.current` to get the latest started
Coverage instance.

- Multiprocessing support in Python 3.8 was broken, but is now fixed.  Closes
`issue 828`_.

- Error handling during reporting has changed slightly.  All reporting methods
now behave the same.  The ``--ignore-errors`` option keeps errors from
stopping the reporting, but files that couldn't parse as Python will always
be reported as warnings.  As with other warnings, you can suppress them with
the ``[run] disable_warnings`` configuration setting.

- Coverage.py no longer fails if the user program deletes its current
directory. Fixes `issue 806`_.  Thanks, Dan Hemberger.

- The scrollbar markers in the HTML report now accurately show the highlighted
lines, regardless of what categories of line are highlighted.

- The hack to accommodate ShiningPanda_ looking for an obsolete internal data
file has been removed, since ShiningPanda 0.22 fixed it four years ago.

- The deprecated `Reporter.file_reporters` property has been removed.

.. _ShiningPanda: https://wiki.jenkins.io/display/JENKINS/ShiningPanda+Plugin
.. _issue 806: https://github.com/nedbat/coveragepy/pull/806
.. _issue 828: https://github.com/nedbat/coveragepy/issues/828


.. _changes_50a5:

5.0a5

----------------------------

- Drop support for Python 3.4

- Dynamic contexts can now be set two new ways, both thanks to Justas
Sadzevičius.

- A plugin can implement a ``dynamic_context`` method to check frames for
 whether a new context should be started.  See
 :ref:`dynamic_context_plugins` for more details.

- Another tool (such as a test runner) can use the new
 :meth:`.Coverage.switch_context` method to explicitly change the context.

- The ``dynamic_context = test_function`` setting now works with Python 2
old-style classes, though it only reports the method name, not the class it
was defined on.  Closes `issue 797`_.

- ``fail_under`` values more than 100 are reported as errors.  Thanks to Mike
Fiedler for closing `issue 746`_.

- The "missing" values in the text output are now sorted by line number, so
that missing branches are reported near the other lines they affect. The
values used to show all missing lines, and then all missing branches.

- Access to the SQLite database used for data storage is now thread-safe.
Thanks, Stephan Richter. This closes `issue 702`_.

- Combining data stored in SQLite is now about twice as fast, fixing `issue
761`_.  Thanks, Stephan Richter.

- The ``filename`` attribute on :class:`.CoverageData` objects has been made
private.  You can use the ``data_filename`` method to get the actual file
name being used to store data, and the ``base_filename`` method to get the
original filename before parallelizing suffixes were added.  This is part of
fixing `issue 708`_.

- Line numbers in the HTML report now align properly with source lines, even
when Chrome's minimum font size is set, fixing `issue 748`_.  Thanks Wen Ye.

.. _issue 702: https://github.com/nedbat/coveragepy/issues/702
.. _issue 708: https://github.com/nedbat/coveragepy/issues/708
.. _issue 746: https://github.com/nedbat/coveragepy/issues/746
.. _issue 748: https://github.com/nedbat/coveragepy/issues/748
.. _issue 761: https://github.com/nedbat/coveragepy/issues/761
.. _issue 797: https://github.com/nedbat/coveragepy/issues/797


.. _changes_50a4:

5.0a4

----------------------------

- You can specify the command line to run your program with the ``[run]
command_line`` configuration setting, as requested in `issue 695`_.

- Coverage will create directories as needed for the data file if they don't
exist, closing `issue 721`_.

- The ``coverage run`` command has always adjusted the first entry in sys.path,
to properly emulate how Python runs your program.  Now this adjustment is
skipped if sys.path[0] is already different than Python's default.  This
fixes `issue 715`_.

- Improvements to context support:

- The "no such table: meta" error is fixed.: `issue 716`_.

- Combining data files is now much faster.

- Python 3.8 (as of today!) passes all tests.

.. _issue 695: https://github.com/nedbat/coveragepy/issues/695
.. _issue 715: https://github.com/nedbat/coveragepy/issues/715
.. _issue 716: https://github.com/nedbat/coveragepy/issues/716
.. _issue 721: https://github.com/nedbat/coveragepy/issues/721


.. _changes_50a3:

5.0a3

----------------------------

- Context support: static contexts let you specify a label for a coverage run,
which is recorded in the data, and retained when you combine files.  See
:ref:`contexts` for more information.

- Dynamic contexts: specifying ``[run] dynamic_context = test_function`` in the
config file will record the test function name as a dynamic context during
execution.  This is the core of "Who Tests What" (`issue 170`_).  Things to
note:

- There is no reporting support yet.  Use SQLite to query the .coverage file
 for information.  Ideas are welcome about how reporting could be extended
 to use this data.

- There's a noticeable slow-down before any test is run.

- Data files will now be roughly N times larger, where N is the number of
 tests you have.  Combining data files is therefore also N times slower.

- No other values for ``dynamic_context`` are recognized yet.  Let me know
 what else would be useful.  I'd like to use a pytest plugin to get better
 information directly from pytest, for example.

.. _issue 170: https://github.com/nedbat/coveragepy/issues/170

- Environment variable substitution in configuration files now supports two
syntaxes for controlling the behavior of undefined variables: if ``VARNAME``
is not defined, ``${VARNAME?}`` will raise an error, and ``${VARNAME-default
value}`` will use "default value".

- Partial support for Python 3.8, which has not yet released an alpha. Fixes
`issue 707`_ and `issue 714`_.

.. _issue 707: https://github.com/nedbat/coveragepy/issues/707
.. _issue 714: https://github.com/nedbat/coveragepy/issues/714


.. _changes_50a2:

5.0a2

----------------------------

- Coverage's data storage has changed.  In version 4.x, .coverage files were
basically JSON.  Now, they are SQLite databases.  This means the data file
can be created earlier than it used to.  A large amount of code was
refactored to support this change.

- Because the data file is created differently than previous releases, you
 may need ``parallel=true`` where you didn't before.

- The old data format is still available (for now) by setting the environment
 variable COVERAGE_STORAGE=json. Please tell me if you think you need to
 keep the JSON format.

- The database schema is guaranteed to change in the future, to support new
 features.  I'm looking for opinions about making the schema part of the
 public API to coverage.py or not.

- Development moved from `Bitbucket`_ to `GitHub`_.

- HTML files no longer have trailing and extra whitespace.

- The sort order in the HTML report is stored in local storage rather than
cookies, closing `issue 611`_.  Thanks, Federico Bond.

- pickle2json, for converting v3 data files to v4 data files, has been removed.

.. _Bitbucket: https://bitbucket.org/ned/coveragepy
.. _GitHub: https://github.com/nedbat/coveragepy

.. _issue 611: https://github.com/nedbat/coveragepy/issues/611


.. _changes_50a1:

5.0a1

----------------------------

- Coverage.py no longer supports Python 2.6 or 3.3.

- The location of the configuration file can now be specified with a
``COVERAGE_RCFILE`` environment variable, as requested in `issue 650`_.

- Namespace packages are supported on Python 3.7, where they used to cause
TypeErrors about path being None. Fixes `issue 700`_.

- A new warning (``already-imported``) is issued if measurable files have
already been imported before coverage.py started measurement.  See
:ref:`cmd_warnings` for more information.

- Running coverage many times for small runs in a single process should be
faster, closing `issue 625`_.  Thanks, David MacIver.

- Large HTML report pages load faster.  Thanks, Pankaj Pandey.

.. _issue 625: https://bitbucket.org/ned/coveragepy/issues/625/lstat-dominates-in-the-case-of-small
.. _issue 650: https://bitbucket.org/ned/coveragepy/issues/650/allow-setting-configuration-file-location
.. _issue 700: https://github.com/nedbat/coveragepy/issues/700


.. _changes_454:

4.5.4

---------------------------

- Multiprocessing support in Python 3.8 was broken, but is now fixed.  Closes
`issue 828`_.

.. _issue 828: https://github.com/nedbat/coveragepy/issues/828


.. _changes_453:

4.5.3

---------------------------

- Only packaging metadata changes.


.. _changes_452:

4.5.2

----------------------------

- Namespace packages are supported on Python 3.7, where they used to cause
TypeErrors about path being None. Fixes `issue 700`_.

- Python 3.8 (as of today!) passes all tests.  Fixes `issue 707`_ and
`issue 714`_.

- Development moved from `Bitbucket`_ to `GitHub`_.

.. _issue 700: https://github.com/nedbat/coveragepy/issues/700
.. _issue 707: https://github.com/nedbat/coveragepy/issues/707
.. _issue 714: https://github.com/nedbat/coveragepy/issues/714

.. _Bitbucket: https://bitbucket.org/ned/coveragepy
.. _GitHub: https://github.com/nedbat/coveragepy


.. _changes_451:

4.5.1

----------------------------

- Now that 4.5 properly separated the ``[run] omit`` and ``[report] omit``
settings, an old bug has become apparent.  If you specified a package name
for ``[run] source``, then omit patterns weren't matched inside that package.
This bug (`issue 638`_) is now fixed.

- On Python 3.7, reporting about a decorated function with no body other than a
docstring would crash coverage.py with an IndexError (`issue 640`_).  This is
now fixed.

- Configurer plugins are now reported in the output of ``--debug=sys``.

.. _issue 638: https://bitbucket.org/ned/coveragepy/issues/638/run-omit-is-ignored-since-45
.. _issue 640: https://bitbucket.org/ned/coveragepy/issues/640/indexerror-reporting-on-an-empty-decorated


.. _changes_45:

4.5

--------------------------

- A new kind of plugin is supported: configurers are invoked at start-up to
allow more complex configuration than the .coveragerc file can easily do.
See :ref:`api_plugin` for details.  This solves the complex configuration
problem described in `issue 563`_.

- The ``fail_under`` option can now be a float.  Note that you must specify the
``[report] precision`` configuration option for the fractional part to be
used.  Thanks to Lars Hupfeldt Nielsen for help with the implementation.
Fixes `issue 631`_.

- The ``include`` and ``omit`` options can be specified for both the ``[run]``
and ``[report]`` phases of execution.  4.4.2 introduced some incorrect
interactions between those phases, where the options for one were confused
for the other.  This is now corrected, fixing `issue 621`_ and `issue 622`_.
Thanks to Daniel Hahler for seeing more clearly than I could.

- The ``coverage combine`` command used to always overwrite the data file, even
when no data had been read from apparently combinable files.  Now, an error
is raised if we thought there were files to combine, but in fact none of them
could be used.  Fixes `issue 629`_.

- The ``coverage combine`` command could get confused about path separators
when combining data collected on Windows with data collected on Linux, as
described in `issue 618`_.  This is now fixed: the result path always uses
the path separator specified in the ``[paths]`` result.

- On Windows, the HTML report could fail when source trees are deeply nested,
due to attempting to create HTML filenames longer than the 250-character
maximum.  Now filenames will never get much larger than 200 characters,
fixing `issue 627`_.  Thanks to Alex Sandro for helping with the fix.

.. _issue 563: https://bitbucket.org/ned/coveragepy/issues/563/platform-specific-configuration
.. _issue 618: https://bitbucket.org/ned/coveragepy/issues/618/problem-when-combining-windows-generated
.. _issue 621: https://bitbucket.org/ned/coveragepy/issues/621/include-ignored-warning-when-using
.. _issue 622: https://bitbucket.org/ned/coveragepy/issues/622/report-omit-overwrites-run-omit
.. _issue 627: https://bitbucket.org/ned/coveragepy/issues/627/failure-generating-html-reports-when-the
.. _issue 629: https://bitbucket.org/ned/coveragepy/issues/629/multiple-use-of-combine-leads-to-empty
.. _issue 631: https://bitbucket.org/ned/coveragepy/issues/631/precise-coverage-percentage-value


.. _changes_442:

4.4.2

----------------------------

- Support for Python 3.7.  In some cases, class and module docstrings are no
longer counted in statement totals, which could slightly change your total
results.

- Specifying both ``--source`` and ``--include`` no longer silently ignores the
include setting, instead it displays a warning. Thanks, Loïc Dachary.  Closes
`issue 265`_ and `issue 101`_.

- Fixed a race condition when saving data and multiple threads are tracing
(`issue 581`_). It could produce a "dictionary changed size during iteration"
RuntimeError.  I believe this mostly but not entirely fixes the race
condition.  A true fix would likely be too expensive.  Thanks, Peter Baughman
for the debugging, and Olivier Grisel for the fix with tests.

- Configuration values which are file paths will now apply tilde-expansion,
closing `issue 589`_.

- Now secondary config files like tox.ini and setup.cfg can be specified
explicitly, and prefixed sections like `[coverage:run]` will be read. Fixes
`issue 588`_.

- Be more flexible about the command name displayed by help, fixing
`issue 600`_. Thanks, Ben Finney.

.. _issue 101: https://bitbucket.org/ned/coveragepy/issues/101/settings-under-report-affect-running
.. _issue 581: https://bitbucket.org/ned/coveragepy/issues/581/race-condition-when-saving-data-under
.. _issue 588: https://bitbucket.org/ned/coveragepy/issues/588/using-rcfile-path-to-toxini-uses-run
.. _issue 589: https://bitbucket.org/ned/coveragepy/issues/589/allow-expansion-in-coveragerc
.. _issue 600: https://bitbucket.org/ned/coveragepy/issues/600/get-program-name-from-command-line-when


.. _changes_441:

4.4.1

----------------------------

- No code changes: just corrected packaging for Python 2.7 Linux wheels.


.. _changes_44:

4.4

--------------------------

- Reports could produce the wrong file names for packages, reporting ``pkg.py``
instead of the correct ``pkg/__init__.py``.  This is now fixed.  Thanks, Dirk
Thomas.

- XML reports could produce ``<source>`` and ``<class>`` lines that together
didn't specify a valid source file path.  This is now fixed. (`issue 526`_)

- Namespace packages are no longer warned as having no code. (`issue 572`_)

- Code that uses ``sys.settrace(sys.gettrace())`` in a file that wasn't being
coverage-measured would prevent correct coverage measurement in following
code. An example of this was running doctests programmatically. This is now
fixed. (`issue 575`_)

- Errors printed by the ``coverage`` command now go to stderr instead of
stdout.

- Running ``coverage xml`` in a directory named with non-ASCII characters would
fail under Python 2. This is now fixed. (`issue 573`_)

.. _issue 526: https://bitbucket.org/ned/coveragepy/issues/526/generated-xml-invalid-paths-for-cobertura
.. _issue 572: https://bitbucket.org/ned/coveragepy/issues/572/no-python-source-warning-for-namespace
.. _issue 573: https://bitbucket.org/ned/coveragepy/issues/573/cant-generate-xml-report-if-some-source
.. _issue 575: https://bitbucket.org/ned/coveragepy/issues/575/running-doctest-prevents-complete-coverage

4.4b1

----------------------------

- Some warnings can now be individually disabled.  Warnings that can be
disabled have a short name appended.  The ``[run] disable_warnings`` setting
takes a list of these warning names to disable. Closes both `issue 96`_ and
`issue 355`_.

- The XML report now includes attributes from version 4 of the Cobertura XML
format, fixing `issue 570`_.

- In previous versions, calling a method that used collected data would prevent
further collection.  For example, `save()`, `report()`, `html_report()`, and
others would all stop collection.  An explicit `start()` was needed to get it
going again.  This is no longer true.  Now you can use the collected data and
also continue measurement. Both `issue 79`_ and `issue 448`_ described this
problem, and have been fixed.

- Plugins can now find unexecuted files if they choose, by implementing the
`find_executable_files` method.  Thanks, Emil Madsen.

- Minimal IronPython support. You should be able to run IronPython programs
under ``coverage run``, though you will still have to do the reporting phase
with CPython.

- Coverage.py has long had a special hack to support CPython's need to measure
the coverage of the standard library tests. This code was not installed by
kitted versions of coverage.py.  Now it is.

.. _issue 79: https://bitbucket.org/ned/coveragepy/issues/79/save-prevents-harvesting-on-stop
.. _issue 96: https://bitbucket.org/ned/coveragepy/issues/96/unhelpful-warnings-produced-when-using
.. _issue 355: https://bitbucket.org/ned/coveragepy/issues/355/warnings-should-be-suppressable
.. _issue 448: https://bitbucket.org/ned/coveragepy/issues/448/save-and-html_report-prevent-further
.. _issue 570: https://bitbucket.org/ned/coveragepy/issues/570/cobertura-coverage-04dtd-support


.. _changes_434:

4.3.4

----------------------------

- Fixing 2.6 in version 4.3.3 broke other things, because the too-tricky
exception wasn't properly derived from Exception, described in `issue 556`_.
A newb mistake; it hasn't been a good few days.

.. _issue 556: https://bitbucket.org/ned/coveragepy/issues/556/43-fails-if-there-are-html-files-in-the


.. _changes_433:

4.3.3

----------------------------

- Python 2.6 support was broken due to a testing exception imported for the
benefit of the coverage.py test suite.  Properly conditionalizing it fixed
`issue 554`_ so that Python 2.6 works again.

.. _issue 554: https://bitbucket.org/ned/coveragepy/issues/554/traceback-on-python-26-starting-with-432


.. _changes_432:

4.3.2

----------------------------

- Using the ``--skip-covered`` option on an HTML report with 100% coverage
would cause a "No data to report" error, as reported in `issue 549`_. This is
now fixed; thanks, Loïc Dachary.

- If-statements can be optimized away during compilation, for example, `if 0:`
or `if __debug__:`.  Coverage.py had problems properly understanding these
statements which existed in the source, but not in the compiled bytecode.
This problem, reported in `issue 522`_, is now fixed.

- If you specified ``--source`` as a directory, then coverage.py would look for
importable Python files in that directory, and could identify ones that had
never been executed at all.  But if you specified it as a package name, that
detection wasn't performed.  Now it is, closing `issue 426`_. Thanks to Loïc
Dachary for the fix.

- If you started and stopped coverage measurement thousands of times in your
process, you could crash Python with a "Fatal Python error: deallocating
None" error.  This is now fixed.  Thanks to Alex Groce for the bug report.

- On PyPy, measuring coverage in subprocesses could produce a warning: "Trace
function changed, measurement is likely wrong: None".  This was spurious, and
has been suppressed.

- Previously, coverage.py couldn't start on Jython, due to that implementation
missing the multiprocessing module (`issue 551`_). This problem has now been
fixed. Also, `issue 322`_ about not being able to invoke coverage
conveniently, seems much better: ``jython -m coverage run myprog.py`` works
properly.

- Let's say you ran the HTML report over and over again in the same output
directory, with ``--skip-covered``. And imagine due to your heroic
test-writing efforts, a file just achieved the goal of 100% coverage. With
coverage.py 4.3, the old HTML file with the less-than-100% coverage would be
left behind.  This file is now properly deleted.

.. _issue 322: https://bitbucket.org/ned/coveragepy/issues/322/cannot-use-coverage-with-jython
.. _issue 426: https://bitbucket.org/ned/coveragepy/issues/426/difference-between-coverage-results-with
.. _issue 522: https://bitbucket.org/ned/coveragepy/issues/522/incorrect-branch-reporting
.. _issue 549: https://bitbucket.org/ned/coveragepy/issues/549/skip-covered-with-100-coverage-throws-a-no
.. _issue 551: https://bitbucket.org/ned/coveragepy/issues/551/coveragepy-cannot-be-imported-in-jython27


.. _changes_431:

4.3.1

----------------------------

- Some environments couldn't install 4.3, as described in `issue 540`_. This is
now fixed.

- The check for conflicting ``--source`` and ``--include`` was too simple in a
few different ways, breaking a few perfectly reasonable use cases, described
in `issue 541`_.  The check has been reverted while we re-think the fix for
`issue 265`_.

.. _issue 540: https://bitbucket.org/ned/coveragepy/issues/540/cant-install-coverage-v43-into-under
.. _issue 541: https://bitbucket.org/ned/coveragepy/issues/541/coverage-43-breaks-nosetest-with-coverage


.. _changes_43:

4.3

--------------------------

Special thanks to **Loïc Dachary**, who took an extraordinary interest in
coverage.py and contributed a number of improvements in this release.

- Subprocesses that are measured with `automatic subprocess measurement`_ used
to read in any pre-existing data file.  This meant data would be incorrectly
carried forward from run to run.  Now those files are not read, so each
subprocess only writes its own data. Fixes `issue 510`_.

- The ``coverage combine`` command will now fail if there are no data files to
combine. The combine changes in 4.2 meant that multiple combines could lose
data, leaving you with an empty .coverage data file. Fixes
`issue 525`_, `issue 412`_, `issue 516`_, and probably `issue 511`_.

- Coverage.py wouldn't execute `sys.excepthook`_ when an exception happened in
your program.  Now it does, thanks to Andrew Hoos.  Closes `issue 535`_.

- Branch coverage fixes:

- Branch coverage could misunderstand a finally clause on a try block that
 never continued on to the following statement, as described in `issue
 493`_.  This is now fixed. Thanks to Joe Doherty for the report and Loïc
 Dachary for the fix.

- A while loop with a constant condition (while True) and a continue
 statement would be mis-analyzed, as described in `issue 496`_. This is now
 fixed, thanks to a bug report by Eli Skeggs and a fix by Loïc Dachary.

- While loops with constant conditions that were never executed could result
 in a non-zero coverage report.  Artem Dayneko reported this in `issue
 502`_, and Loïc Dachary provided the fix.

- The HTML report now supports a ``--skip-covered`` option like the other
reporting commands.  Thanks, Loïc Dachary for the implementation, closing
`issue 433`_.

- Options can now be read from a tox.ini file, if any. Like setup.cfg, sections
are prefixed with "coverage:", so ``[run]`` options will be read from the
``[coverage:run]`` section of tox.ini. Implements part of `issue 519`_.
Thanks, Stephen Finucane.

- Specifying both ``--source`` and ``--include`` no longer silently ignores the
include setting, instead it fails with a message. Thanks, Nathan Land and
Loïc Dachary. Closes `issue 265`_.

- The ``Coverage.combine`` method has a new parameter, ``strict=False``, to
support failing if there are no data files to combine.

- When forking subprocesses, the coverage data files would have the same random
number appended to the file name. This didn't cause problems, because the
file names had the process id also, making collisions (nearly) impossible.
But it was disconcerting.  This is now fixed.

- The text report now properly sizes headers when skipping some files, fixing
`issue 524`_. Thanks, Anthony Sottile and Loïc Dachary.

- Coverage.py can now search .pex files for source, just as it can .zip and
.egg.  Thanks, Peter Ebden.

- Data files are now about 15% smaller.

- Improvements in the ``[run] debug`` setting:

- The "dataio" debug setting now also logs when data files are deleted during
 combining or erasing.

- A new debug option, "multiproc", for logging the behavior of
 ``concurrency=multiprocessing``.

- If you used the debug options "config" and "callers" together, you'd get a
 call stack printed for every line in the multi-line config output. This is
 now fixed.

- Fixed an unusual bug involving multiple coding declarations affecting code
containing code in multi-line strings: `issue 529`_.

- Coverage.py will no longer be misled into thinking that a plain file is a
package when interpreting ``--source`` options.  Thanks, Cosimo Lupo.

- If you try to run a non-Python file with coverage.py, you will now get a more
useful error message. `Issue 514`_.

- The default pragma regex changed slightly, but this will only matter to you
if you are deranged and use mixed-case pragmas.

- Deal properly with non-ASCII file names in an ASCII-only world, `issue 533`_.

- Programs that set Unicode configuration values could cause UnicodeErrors when
generating HTML reports.  Pytest-cov is one example.  This is now fixed.

- Prevented deprecation warnings from configparser that happened in some
circumstances, closing `issue 530`_.

- Corrected the name of the jquery.ba-throttle-debounce.js library. Thanks,
Ben Finney.  Closes `issue 505`_.

- Testing against PyPy 5.6 and PyPy3 5.5.

- Switched to pytest from nose for running the coverage.py tests.

- Renamed AUTHORS.txt to CONTRIBUTORS.txt, since there are other ways to
contribute than by writing code. Also put the count of contributors into the
author string in setup.py, though this might be too cute.

.. _sys.excepthook: https://docs.python.org/3/library/sys.htmlsys.excepthook
.. _issue 265: https://bitbucket.org/ned/coveragepy/issues/265/when-using-source-include-is-silently
.. _issue 412: https://bitbucket.org/ned/coveragepy/issues/412/coverage-combine-should-error-if-no
.. _issue 433: https://bitbucket.org/ned/coveragepy/issues/433/coverage-html-does-not-suport-skip-covered
.. _issue 493: https://bitbucket.org/ned/coveragepy/issues/493/confusing-branching-failure
.. _issue 496: https://bitbucket.org/ned/coveragepy/issues/496/incorrect-coverage-with-branching-and
.. _issue 502: https://bitbucket.org/ned/coveragepy/issues/502/incorrect-coverage-report-with-cover
.. _issue 505: https://bitbucket.org/ned/coveragepy/issues/505/use-canonical-filename-for-debounce
.. _issue 514: https://bitbucket.org/ned/coveragepy/issues/514/path-to-problem-file-not-reported-when
.. _issue 510: https://bitbucket.org/ned/coveragepy/issues/510/erase-still-needed-in-42
.. _issue 511: https://bitbucket.org/ned/coveragepy/issues/511/version-42-coverage-combine-empties
.. _issue 516: https://bitbucket.org/ned/coveragepy/issues/516/running-coverage-combine-twice-deletes-all
.. _issue 519: https://bitbucket.org/ned/coveragepy/issues/519/coverage-run-sections-in-toxini-or-as
.. _issue 524: https://bitbucket.org/ned/coveragepy/issues/524/coverage-report-with-skip-covered-column
.. _issue 525: https://bitbucket.org/ned/coveragepy/issues/525/coverage-combine-when-not-in-parallel-mode
.. _issue 529: https://bitbucket.org/ned/coveragepy/issues/529/encoding-marker-may-only-appear-on-the
.. _issue 530: https://bitbucket.org/ned/coveragepy/issues/530/deprecationwarning-you-passed-a-bytestring
.. _issue 533: https://bitbucket.org/ned/coveragepy/issues/533/exception-on-unencodable-file-name
.. _issue 535: https://bitbucket.org/ned/coveragepy/issues/535/sysexcepthook-is-not-called


.. _changes_42:

4.2

--------------------------

- Since ``concurrency=multiprocessing`` uses subprocesses, options specified on
the coverage.py command line will not be communicated down to them.  Only
options in the configuration file will apply to the subprocesses.
Previously, the options didn't apply to the subprocesses, but there was no
indication.  Now it is an error to use ``--concurrency=multiprocessing`` and
other run-affecting options on the command line.  This prevents
failures like those reported in `issue 495`_.

- Filtering the HTML report is now faster, thanks to Ville Skyttä.

.. _issue 495: https://bitbucket.org/ned/coveragepy/issues/495/branch-and-concurrency-are-conflicting

4.2b1

----------------------------

Work from the PyCon 2016 Sprints!

- BACKWARD INCOMPATIBILITY: the ``coverage combine`` command now ignores an
existing ``.coverage`` data file.  It used to include that file in its
combining.  This caused confusing results, and extra tox "clean" steps.  If
you want the old behavior, use the new ``coverage combine --append`` option.

- The ``concurrency`` option can now take multiple values, to support programs
using multiprocessing and another library such as eventlet.  This is only
possible in the configuration file, not from the command line. The
configuration file is the only way for sub-processes to all run with the same
options.  Fixes `issue 484`_.  Thanks to Josh Williams for prototyping.

- Using a ``concurrency`` setting of ``multiprocessing`` now implies
``--parallel`` so that the main program is measured similarly to the
sub-processes.

- When using `automatic subprocess measurement`_, running coverage commands
would create spurious data files.  This is now fixed, thanks to diagnosis and
testing by Dan Riti.  Closes `issue 492`_.

- A new configuration option, ``report:sort``, controls what column of the
text report is used to sort the rows.  Thanks to Dan Wandschneider, this
closes `issue 199`_.

- The HTML report has a more-visible indicator for which column is being
sorted.  Closes `issue 298`_, thanks to Josh Williams.

- If the HTML report cannot find the source for a file, the message now
suggests using the ``-i`` flag to allow the report to continue. Closes
`issue 231`_, thanks, Nathan Land.

- When reports are ignoring errors, there's now a warning if a file cannot be
parsed, rather than being silently ignored.  Closes `issue 396`_. Thanks,
Matthew Boehm.

- A new option for ``coverage debug`` is available: ``coverage debug config``
shows the current configuration.  Closes `issue 454`_, thanks to Matthew
Boehm.

- Running coverage as a module (``python -m coverage``) no longer shows the
program name as ``__main__.py``.  Fixes `issue 478`_.  Thanks, Scott Belden.

- The `test_helpers` module has been moved into a separate pip-installable
package: `unittest-mixins`_.

.. _automatic subprocess measurement: https://coverage.readthedocs.io/en/latest/subprocess.html
.. _issue 199: https://bitbucket.org/ned/coveragepy/issues/199/add-a-way-to-sort-the-text-report
.. _issue 231: https://bitbucket.org/ned/coveragepy/issues/231/various-default-behavior-in-report-phase
.. _issue 298: https://bitbucket.org/ned/coveragepy/issues/298/show-in-html-report-that-the-columns-are
.. _issue 396: https://bitbucket.org/ned/coveragepy/issues/396/coverage-xml-shouldnt-bail-out-on-parse
.. _issue 454: https://bitbucket.org/ned/coveragepy/issues/454/coverage-debug-config-should-be
.. _issue 478: https://bitbucket.org/ned/coveragepy/issues/478/help-shows-silly-program-name-when-running
.. _issue 484: https://bitbucket.org/ned/coveragepy/issues/484/multiprocessing-greenlet-concurrency
.. _issue 492: https://bitbucket.org/ned/coveragepy/issues/492/subprocess-coverage-strange-detection-of
.. _unittest-mixins: https://pypi.org/project/unittest-mixins/


.. _changes_41:

4.1

--------------------------

- The internal attribute `Reporter.file_reporters` was removed in 4.1b3.  It
should have come has no surprise that there were third-party tools out there
using that attribute.  It has been restored, but with a deprecation warning.

4.1b3

----------------------------

- When running your program, execution can jump from an ``except X:`` line to
some other line when an exception other than ``X`` happens.  This jump is no
longer considered a branch when measuring branch coverage.

- When measuring branch coverage, ``yield`` statements that were never resumed
were incorrectly marked as missing, as reported in `issue 440`_.  This is now
fixed.

- During branch coverage of single-line callables like lambdas and generator
expressions, coverage.py can now distinguish between them never being called,
or being called but not completed.  Fixes `issue 90`_, `issue 460`_ and
`issue 475`_.

- The HTML report now has a map of the file along the rightmost edge of the
page, giving an overview of where the missed lines are.  Thanks, Dmitry
Shishov.

- The HTML report now uses different monospaced fonts, favoring Consolas over
Courier.  Along the way, `issue 472`_ about not properly handling one-space
indents was fixed.  The index page also has slightly different styling, to
try to make the clickable detail pages more apparent.

- Missing branches reported with ``coverage report -m`` will now say ``->exit``
for missed branches to the exit of a function, rather than a negative number.
Fixes `issue 469`_.

- ``coverage --help`` and ``coverage --version`` now mention which tracer is
installed, to help diagnose problems. The docs mention which features need
the C extension. (`issue 479`_)

- Officially support PyPy 5.1, which required no changes, just updates to the
docs.

- The `Coverage.report` function had two parameters with non-None defaults,
which have been changed.  `show_missing` used to default to True, but now
defaults to None.  If you had been calling `Coverage.report` without
specifying `show_missing`, you'll need to explicitly set it to True to keep
the same behavior.  `skip_covered` used to default to False. It is now None,
which doesn't change the behavior.  This fixes `issue 485`_.

- It's never been possible to pass a namespace module to one of the analysis
functions, but now at least we raise a more specific error message, rather
than getting confused. (`issue 456`_)

- The `coverage.process_startup` function now returns the `Coverage` instance
it creates, as suggested in `issue 481`_.

- Make a small tweak to how we compare threads, to avoid buggy custom
comparison code in thread classes. (`issue 245`_)

.. _issue 90: https://bitbucket.org/ned/coveragepy/issues/90/lambda-expression-confuses-branch
.. _issue 245: https://bitbucket.org/ned/coveragepy/issues/245/change-solution-for-issue-164
.. _issue 440: https://bitbucket.org/ned/coveragepy/issues/440/yielded-twisted-failure-marked-as-missed
.. _issue 456: https://bitbucket.org/ned/coveragepy/issues/456/coverage-breaks-with-implicit-namespaces
.. _issue 460: https://bitbucket.org/ned/coveragepy/issues/460/confusing-html-report-for-certain-partial
.. _issue 469: https://bitbucket.org/ned/coveragepy/issues/469/strange-1-line-number-in-branch-coverage
.. _issue 472: https://bitbucket.org/ned/coveragepy/issues/472/html-report-indents-incorrectly-for-one
.. _issue 475: https://bitbucket.org/ned/coveragepy/issues/475/generator-expression-is-marked-as-not
.. _issue 479: https://bitbucket.org/ned/coveragepy/issues/479/clarify-the-need-for-the-c-extension
.. _issue 481: https://bitbucket.org/ned/coveragepy/issues/481/asyncioprocesspoolexecutor-tracing-not
.. _issue 485: https://bitbucket.org/ned/coveragepy/issues/485/coveragereport-ignores-show_missing-and

4.1b2

----------------------------

- Problems with the new branch measurement in 4.1 beta 1 were fixed:

- Class docstrings were considered executable.  Now they no longer are.

- ``yield from`` and ``await`` were considered returns from functions, since
 they could transfer control to the caller.  This produced unhelpful
 "missing branch" reports in a number of circumstances.  Now they no longer
 are considered returns.

- In unusual situations, a missing branch to a negative number was reported.
 This has been fixed, closing `issue 466`_.

- The XML report now produces correct package names for modules found in
directories specified with ``source=``.  Fixes `issue 465`_.

- ``coverage report`` won't produce trailing whitespace.

.. _issue 465: https://bitbucket.org/ned/coveragepy/issues/465/coveragexml-produces-package-names-with-an
.. _issue 466: https://bitbucket.org/ned/coveragepy/issues/466/impossible-missed-branch-to-a-negative

4.1b1

----------------------------

- Branch analysis has been rewritten: it used to be based on bytecode, but now
uses AST analysis.  This has changed a number of things:

- More code paths are now considered runnable, especially in
 ``try``/``except`` structures.  This may mean that coverage.py will
 identify more code paths as uncovered.  This could either raise or lower
 your overall coverage number.

- Python 3.5's ``async`` and ``await`` keywords are properly supported,
 fixing `issue 434`_.

- Some long-standing branch coverage bugs were fixed:

 - `issue 129`_: functions with only a docstring for a body would
   incorrectly report a missing branch on the ``def`` line.

 - `issue 212`_: code in an ``except`` block could be incorrectly marked as
   a missing branch.

 - `issue 146`_: context managers (``with`` statements) in a loop or ``try``
   block could confuse the branch measurement, reporting incorrect partial
   branches.

 - `issue 422`_: in Python 3.5, an actual partial branch could be marked as
   complete.

- Pragmas to disable coverage measurement can now be used on decorator lines,
and they will apply to the entire function or class being decorated.  This
implements the feature requested in `issue 131`_.

- Multiprocessing support is now available on Windows.  Thanks, Rodrigue
Cloutier.

- Files with two encoding declarations are properly supported, fixing
`issue 453`_. Thanks, Max Linke.

- Non-ascii characters in regexes in the configuration file worked in 3.7, but
stopped working in 4.0.  Now they work again, closing `issue 455`_.

- Form-feed characters would prevent accurate determination of the beginning of
statements in the rest of the file.  This is now fixed, closing `issue 461`_.

.. _issue 129: https://bitbucket.org/ned/coveragepy/issues/129/misleading-branch-coverage-of-empty
.. _issue 131: https://bitbucket.org/ned/coveragepy/issues/131/pragma-on-a-decorator-line-should-affect
.. _issue 146: https://bitbucket.org/ned/coveragepy/issues/146/context-managers-confuse-branch-coverage
.. _issue 212: https://bitbucket.org/ned/coveragepy/issues/212/coverage-erroneously-reports-partial
.. _issue 422: https://bitbucket.org/ned/coveragepy/issues/422/python35-partial-branch-marked-as-fully
.. _issue 434: https://bitbucket.org/ned/coveragepy/issues/434/indexerror-in-python-35
.. _issue 453: https://bitbucket.org/ned/coveragepy/issues/453/source-code-encoding-can-only-be-specified
.. _issue 455: https://bitbucket.org/ned/coveragepy/issues/455/unusual-exclusions-stopped-working-in
.. _issue 461: https://bitbucket.org/ned/coveragepy/issues/461/multiline-asserts-need-too-many-pragma


.. _changes_403:

Links

• PyPI: https://pypi.org/project/coverage
• Changelog: https://pyup.io/changelogs/coverage/
• Repo: https://github.com/nedbat/coveragepy