CHANGES.rst

Change history for coverage.py

These changes are listed in decreasing version number order. Note this can be different from a strict chronological order when there are two branches in development at the same time, such as 4.5.x and 5.0.

Unreleased

• Debug: added pybehave to the list of cmd_debug and cmd_run_debug options.
• Fix: show an intelligible error message if --concurrency=multiprocessing is used without a configuration file. Closes issue 1320.

Version 6.3.1 — 2022-02-01

• Fix: deadlocks could occur when terminating processes. Some of these deadlocks (described in issue 1310) are now fixed.
• Fix: a signal handler was being set from multiple threads, causing an error: "ValueError: signal only works in main thread". This is now fixed, closing issue 1312.
• Fix: --precision on the command-line was being ignored while considering --fail-under. This is now fixed, thanks to Marcelo Trylesinski.
• Fix: releases no longer provide 3.11.0-alpha wheels. Coverage.py uses CPython internal fields which are moving during the alpha phase. Fixes issue 1316.

Version 6.3 — 2022-01-25

• Feature: Added the lcov command to generate reports in LCOV format. Thanks, Bradley Burns. Closes issues 587 and 626.
• Feature: the coverage data file can now be specified on the command line with the --data-file option in any command that reads or writes data. This is in addition to the existing COVERAGE_FILE environment variable. Closes issue 624. Thanks, Nikita Bloshchanevich.
• Feature: coverage measurement data will now be written when a SIGTERM signal is received by the process. This includes Process.terminate <python:multiprocessing.Process.terminate>, and other ways to terminate a process. Currently this is only on Linux and Mac; Windows is not supported. Fixes issue 1307.
• Dropped support for Python 3.6, which reached end-of-life on 2021-12-23.
• Updated Python 3.11 support to 3.11.0a4, fixing issue 1294.
• Fix: the coverage data file is now created in a more robust way, to avoid problems when multiple processes are trying to write data at once. Fixes issues 1303 and 883.
• Fix: a .gitignore file will only be written into the HTML report output directory if the directory is empty. This should prevent certain unfortunate accidents of writing the file where it is not wanted.
• Releases now have MacOS arm64 wheels for Apple Silicon, fixing issue 1288.

Version 6.2 — 2021-11-26

• Feature: Now the --concurrency setting can now have a list of values, so that threads and another lightweight threading package can be measured together, such as --concurrency=gevent,thread. Closes issue 1012 and issue 1082.
• Fix: A module specified as the source setting is imported during startup, before the user program imports it. This could cause problems if the rest of the program isn't ready yet. For example, issue 1203 describes a Django setting that is accessed before settings have been configured. Now the early import is wrapped in a try/except so errors then don't stop execution.
• Fix: A colon in a decorator expression would cause an exclusion to end too early, preventing the exclusion of the decorated function. This is now fixed.
• Fix: The HTML report now will not overwrite a .gitignore file that already exists in the HTML output directory (follow-on for issue 1244).
• API: The exceptions raised by Coverage.py have been specialized, to provide finer-grained catching of exceptions by third-party code.
• API: Using suffix=False when constructing a Coverage object with multiprocessing wouldn't suppress the data file suffix (issue 989). This is now fixed.
• Debug: The coverage debug data command will now sniff out combinable data files, and report on all of them.
• Debug: The coverage debug command used to accept a number of topics at a time, and show all of them, though this was never documented. This no longer works, to allow for command-line options in the future.

Version 6.1.2 — 2021-11-10

• Python 3.11 is supported (tested with 3.11.0a2). One still-open issue has to do with exits through with-statements.
• Fix: When remapping file paths through the [paths] setting while combining, the [run] relative_files setting was ignored, resulting in absolute paths for remapped file names (issue 1147). This is now fixed.
• Fix: Complex conditionals over excluded lines could have incorrectly reported a missing branch (issue 1271). This is now fixed.
• Fix: More exceptions are now handled when trying to parse source files for reporting. Problems that used to terminate coverage.py can now be handled with [report] ignore_errors. This helps with plugins failing to read files (django_coverage_plugin issue 78).
• Fix: Removed another vestige of jQuery from the source tarball (issue 840).
• Fix: Added a default value for a new-to-6.x argument of an internal class. This unsupported class is being used by coveralls (issue 1273). Although I'd rather not "fix" unsupported interfaces, it's actually nicer with a default value.

Version 6.1.1 — 2021-10-31

• Fix: The sticky header on the HTML report didn't work unless you had branch coverage enabled. This is now fixed: the sticky header works for everyone. (Do people still use coverage without branch measurement!? j/k)
• Fix: When using explicitly declared namespace packages, the "already imported a file that will be measured" warning would be issued (issue 888). This is now fixed.

Version 6.1 — 2021-10-30

• 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: ned@nedbatchelder.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.

Version 6.0.2 — 2021-10-11

• 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 unexecuted, 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 .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.

Version 6.0.1 — 2021-10-06

• 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.

Version 6.0 — 2021-10-03

• 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).
• 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.

Version 6.0b1 — 2021-07-18

• 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 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).

Version 5.6b1 — 2021-04-13

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.

Version 5.5 — 2021-02-28

• coverage combine has a new option, --keep to keep the original data files after combining them. The default is still to delete the files after they have been combined. This was requested in issue 1108 and implemented in pull request 1110. Thanks, Éric Larivière.
• When reporting missing branches in coverage report, branches aren't reported that jump to missing lines. This adds to the long-standing behavior of not reporting branches from missing lines. Now branches are only reported if both the source and destination lines are executed. Closes both issue 1065 and issue 955.
• Minor improvements to the HTML report:
  • The state of the line visibility selector buttons is saved in local storage so you don't have to fiddle with them so often, fixing issue 1123.
  • It has a little more room for line numbers so that 4-digit numbers work well, fixing issue 1124.
• Improved the error message when combining line and branch data, so that users will be more likely to understand what's happening, closing issue 803.

Version 5.4 — 2021-01-24

• The text report produced by coverage report now always outputs a TOTAL line, even if only one Python file is reported. This makes regex parsing of the output easier. Thanks, Judson Neer. This had been requested a number of times (issue 1086, issue 922, issue 732).
• The skip_covered and skip_empty settings in the configuration file can now be specified in the [html] section, so that text reports and HTML reports can use separate settings. The HTML report will still use the [report] settings if there isn't a value in the [html] section. Closes issue 1090.
• Combining files on Windows across drives now works properly, fixing issue 577. Thanks, Valentin Lab.
• Fix an obscure warning from deep in the _decimal module, as reported in issue 1084.
• Update to support Python 3.10 alphas in progress, including PEP 626: Precise line numbers for debugging and other tools.

Version 5.3.1 — 2020-12-19

• When using --source on a large source tree, v5.x was slower than previous versions. This performance regression is now fixed, closing issue 1037.
• Mysterious SQLite errors can happen on PyPy, as reported in issue 1010. An immediate retry seems to fix the problem, although it is an unsatisfying solution.
• The HTML report now saves the sort order in a more widely supported way, fixing issue 986. Thanks, Sebastián Ramírez (pull request 1066).
• The HTML report pages now have a Sleepy Snake <sleepy> favicon.
• Wheels are now provided for manylinux2010, and for PyPy3 (pp36 and pp37).
• Continuous integration has moved from Travis and AppVeyor to GitHub Actions.

Version 5.3 — 2020-09-13

• The source setting has always been interpreted as either a file path or a module, depending on which existed. If both interpretations were valid, it was assumed to be a file path. The new source_pkgs setting can be used to name a package to disambiguate this case. Thanks, Thomas Grainger. Fixes issue 268.
• If a plugin was disabled due to an exception, we used to still try to record its information, causing an exception, as reported in issue 1011. This is now fixed.

Older changes

The complete history is available in the coverage.py docs.