Include driver code in code coverage to enable proper self-test

[dvdoug]

Hello @sebastianbergmann

Please see attached a PR to remove @codeCoverageIgnore declarations from the driver classes.

Rationale for the change is this:

• In the Xdebug driver, there is code to cleanup bad output from Xdebug (https://github.com/sebastianbergmann/php-code-coverage/blob/master/src/Driver/Xdebug.php#L76)
• When Xdebug is configured to return branch coverage data (Support for Path Coverage #380), the data that is returned is in a different format from that used by line coverage (see https://xdebug.org/docs/code_coverage)
• This code would therefore need to be adjusted as part of work on Support for Path Coverage #380
• Except that Xdebug returning such bogus data seems like a really weird thing for it to do, and upon investigation I cannot make it do that in my tests
• git blame reveals the code has been in the code base since v2 (see 577fdf3 and 121d8c7), which combined with the fact I cannot reproduce the behaviour strongly suggests to me that it was to workaround an issue in an ancient version of Xdebug that has long since been fixed
• as a final confirmation to prove the code is now obsolete before submitting a PR to remove it, I wanted to check the code coverage data from php-code-coverage's own test suite - if the code was not executed but the test suite was still passing then that would provide additional reassurance that it could be safely removed
• except that the drivers are excluded from code coverage so it is not possible to use the coverage report to do this

The drivers have been excluded for a very long time, the commit that originally introduced the exclusion for the whole Xdebug driver didn't include any rationale, it simply says "Simplify" (see 9db2cc4). Since then, drivers for phpdbg and pcov have been added but I can't find any reason for the exclusions there other than cargo-culting/copy-pasting.

I can't think of a reason why they should not be included, are you able to remember that far back and why you might have initially excluded them? The phpdbg driver in particular does a lot of post-processing on the data before handing it off and it would be good to have that show up in reports as something that doesn't have tests.

[codecov]

Codecov Report

Merging #745 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #745   +/-   ##
=========================================
  Coverage     81.96%   81.96%           
- Complexity      842      843    +1     
=========================================
  Files            36       36           
  Lines          2484     2484           
=========================================
  Hits           2036     2036           
  Misses          448      448           

Impacted Files	Coverage Δ	Complexity Δ
src/Driver/PCOV.php	30.00% <ø> (ø)	3.00 <0.00> (ø)
src/Driver/PHPDBG.php	0.00% <ø> (ø)	13.00 <0.00> (ø)
src/Driver/Xdebug.php	0.00% <ø> (ø)	15.00 <0.00> (ø)
src/Report/Text.php	75.20% <0.00%> (ø)	23.00% <0.00%> (ø%)

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[sebastianbergmann]

@derickr Do you think that https://github.com/sebastianbergmann/php-code-coverage/blob/master/src/Driver/Xdebug.php#L76 can be removed?

[sebastianbergmann]

I do not remember the rationale for ignoring the drivers from code coverage.

[derickr]

I could never really reproduce Xdebug showing the wrong line numbers, except for a few cases where PHP would add (internally) an extra line at the end of a script. But that's a long time ago, so I think this can be removed.

[sebastianbergmann]

Thank you, @derickr.