Coverage

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

- Deprecated: The ``annotate`` command and the ``Coverage.annotate`` function
will be removed in a future version, unless people let me know that they are
using it. Instead, the ``html`` command gives better-looking (and more
accurate) output, and the ``report -m`` command will tell you line numbers of
missing lines. Please get in touch if you have a reason to use ``annotate``
over those better options: nednedbatchelder.com.

- Feature: Coverage now sets an environment variable, ``COVERAGE_RUN`` when
running your code with the ``coverage run`` command. The value is not
important, and may change in the future. Closes `issue 553`_.

- Feature: The HTML report pages for Python source files now have a sticky
header so the file name and controls are always visible.

- Feature: The ``xml`` and ``json`` commands now describe what they wrote
where.

- Feature: The ``html``, ``combine``, ``xml``, and ``json`` commands all accept
a ``-q/--quiet`` option to suppress the messages they write to stdout about
what they are doing (`issue 1254`_).

- Feature: The ``html`` command writes a ``.gitignore`` file into the HTML
output directory, to prevent the report from being committed to git. If you
want to commit it, you will need to delete that file. Closes `issue 1244`_.

- Feature: Added support for PyPy 3.8.

- Fix: More generated code is now excluded from measurement. Code such as
`attrs`_ boilerplate, or doctest code, was being measured though the
synthetic line numbers meant they were never reported. Once Cython was
involved though, the generated .so files were parsed as Python, raising
syntax errors, as reported in `issue 1160`_. This is now fixed.

- Fix: When sorting human-readable names, numeric components are sorted
correctly: file10.py will appear after file9.py. This applies to file names,
module names, environment variables, and test contexts.

- Performance: Branch coverage measurement is faster, though you might only
notice on code that is executed many times, such as long-running loops.

- Build: jQuery is no longer used or vendored (`issue 840`_ and `issue 1118`_).
Huge thanks to Nils Kattenbeck (septatrix) for the conversion to vanilla
JavaScript in `pull request 1248`_.

.. _issue 553: https://github.com/nedbat/coveragepy/issues/553
.. _issue 840: https://github.com/nedbat/coveragepy/issues/840
.. _issue 1118: https://github.com/nedbat/coveragepy/issues/1118
.. _issue 1160: https://github.com/nedbat/coveragepy/issues/1160
.. _issue 1244: https://github.com/nedbat/coveragepy/issues/1244
.. _pull request 1248: https://github.com/nedbat/coveragepy/pull/1248
.. _issue 1254: https://github.com/nedbat/coveragepy/issues/1254
.. _attrs: https://www.attrs.org/


.. _changes_602:

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

- Namespace packages being measured weren't properly handled by the new code
that ignores third-party packages. If the namespace package was installed, it
was ignored as a third-party package. That problem (`issue 1231`_) is now
fixed.

- Packages named as "source packages" (with ``source``, or ``source_pkgs``, or
pytest-cov's ``--cov``) might have been only partially measured. Their
top-level statements could be marked as un-executed, because they were
imported by coverage.py before measurement began (`issue 1232`_). This is
now fixed, but the package will be imported twice, once by coverage.py, then
again by your test suite. This could cause problems if importing the package
has side effects.

- The :meth:`.CoverageData.contexts_by_lineno` method was documented to return
a dict, but was returning a defaultdict. Now it returns a plain dict. It
also no longer returns negative numbered keys.

.. _issue 1231: https://github.com/nedbat/coveragepy/issues/1231
.. _issue 1232: https://github.com/nedbat/coveragepy/issues/1232


.. _changes_601:

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

- In 6.0, the coverage.py exceptions moved from coverage.misc to
coverage.exceptions. These exceptions are not part of the public supported
API, CoverageException is. But a number of other third-party packages were
importing the exceptions from coverage.misc, so they are now available from
there again (`issue 1226`_).

- Changed an internal detail of how tomli is imported, so that tomli can use
coverage.py for their own test suite (`issue 1228`_).

- Defend against an obscure possibility under code obfuscation, where a
function can have an argument called "self", but no local named "self"
(`pull request 1210`_). Thanks, Ben Carlsson.

.. _pull request 1210: https://github.com/nedbat/coveragepy/pull/1210
.. _issue 1226: https://github.com/nedbat/coveragepy/issues/1226
.. _issue 1228: https://github.com/nedbat/coveragepy/issues/1228


.. _changes_60:

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

- The ``coverage html`` command now prints a message indicating where the HTML
report was written. Fixes `issue 1195`_.

- The ``coverage combine`` command now prints messages indicating each data
file being combined. Fixes `issue 1105`_.

- The HTML report now includes a sentence about skipped files due to
``skip_covered`` or ``skip_empty`` settings. Fixes `issue 1163`_.

- Unrecognized options in the configuration file are no longer errors. They are
now warnings, to ease the use of coverage across versions. Fixes `issue
1035`_.

- Fix handling of exceptions through context managers in Python 3.10. A missing
exception is no longer considered a missing branch from the with statement.
Fixes `issue 1205`_.

- Fix another rarer instance of "Error binding parameter 0 - probably
unsupported type." (`issue 1010 <issue 1010b_>`_).

- Creating a directory for the coverage data file now is safer against
conflicts when two coverage runs happen simultaneously (`pull 1220`_).
Thanks, Clément Pit-Claudel.

.. _issue 1010b: https://github.com/nedbat/coveragepy/issues/1010
.. _issue 1035: https://github.com/nedbat/coveragepy/issues/1035
.. _issue 1105: https://github.com/nedbat/coveragepy/issues/1105
.. _issue 1163: https://github.com/nedbat/coveragepy/issues/1163
.. _issue 1195: https://github.com/nedbat/coveragepy/issues/1195
.. _issue 1205: https://github.com/nedbat/coveragepy/issues/1205
.. _pull 1220: https://github.com/nedbat/coveragepy/pull/1220


.. _changes_60b1:

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

- Dropped support for Python 2.7, PyPy 2, and Python 3.5.

- Added support for the Python 3.10 ``match/case`` syntax.

- Data collection is now thread-safe. There may have been rare instances of
exceptions raised in multi-threaded programs.

- Plugins (like the `Django coverage plugin`_) were generating "Already
imported a file that will be measured" warnings about Django itself. These
have been fixed, closing `issue 1150`_.

- Warnings generated by coverage.py are now real Python warnings.

- Using ``--fail-under=100`` with coverage near 100% could result in the
self-contradictory message :code:`total of 100 is less than fail-under=100`.
This bug (`issue 1168`_) is now fixed.

- The ``COVERAGE_DEBUG_FILE`` environment variable now accepts ``stdout`` and
``stderr`` to write to those destinations.

- TOML parsing now uses the `tomli`_ library.

- Some minor changes to usually invisible details of the HTML report:

- Use a modern hash algorithm when fingerprinting, for high-security
environments (`issue 1189`_). When generating the HTML report, we save the
hash of the data, to avoid regenerating an unchanged HTML page. We used to
use MD5 to generate the hash, and now use SHA-3-256. This was never a
security concern, but security scanners would notice the MD5 algorithm and
raise a false alarm.

- Change how report file names are generated, to avoid leading underscores
(`issue 1167`_), to avoid rare file name collisions (`issue 584`_), and to
avoid file names becoming too long (`issue 580`_).

.. _Django coverage plugin: https://pypi.org/project/django-coverage-plugin/
.. _issue 580: https://github.com/nedbat/coveragepy/issues/580
.. _issue 584: https://github.com/nedbat/coveragepy/issues/584
.. _issue 1150: https://github.com/nedbat/coveragepy/issues/1150
.. _issue 1167: https://github.com/nedbat/coveragepy/issues/1167
.. _issue 1168: https://github.com/nedbat/coveragepy/issues/1168
.. _issue 1189: https://github.com/nedbat/coveragepy/issues/1189
.. _tomli: https://pypi.org/project/tomli/


.. _changes_56b1:

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

Note: 5.6 final was never released. These changes are part of 6.0.

- Third-party packages are now ignored in coverage reporting. This solves a
few problems:

- Coverage will no longer report about other people's code (`issue 876`_).
This is true even when using ``--source=.`` with a venv in the current
directory.

- Coverage will no longer generate "Already imported a file that will be
measured" warnings about coverage itself (`issue 905`_).

- The HTML report uses j/k to move up and down among the highlighted chunks of
code. They used to highlight the current chunk, but 5.0 broke that behavior.
Now the highlighting is working again.

- The JSON report now includes ``percent_covered_display``, a string with the
total percentage, rounded to the same number of decimal places as the other
reports' totals.

.. _issue 876: https://github.com/nedbat/coveragepy/issues/876
.. _issue 905: https://github.com/nedbat/coveragepy/issues/905


.. _changes_55: