[wp-trac] [WordPress Trac] #51734: Run core unit tests from src again, again

[WordPress Trac]

#51734: Run core unit tests from src again, again
------------------------------+----------------------------
 Reporter:  johnbillion       |      Owner:  (none)
     Type:  task (blessed)    |     Status:  new
 Priority:  normal            |  Milestone:  Future Release
Component:  Build/Test Tools  |    Version:  5.1
 Severity:  normal            |   Keywords:
  Focuses:                    |
------------------------------+----------------------------
 Previously: #45863

 When a developer first runs the test suite locally they are prompted to
 create a `wp-tests-config.php` file based on the `wp-tests-config-
 sample.php` file. This file defines the test directory for the core tests
 as `build` rather than `src`.

 Running the core tests from `build` results in several problems:

 1. Running a build is slow. It copies all the files and builds, validates,
 and minifies all the CSS and JS. None of this should be necessary for PHP
 testing.
 2. A developer iterating on a patch in the source file has no way of
 knowing that their file is not actually being tested when running the
 tests, unless they run the build each time or start and run the file
 watcher. This is an easy step to forget.
 3. PHP errors display a stack trace from `build` instead `src`.
 4. Breakpoint debugging isn't fun as it also uses the stack trace from
 `build` instead of `src`.
 5. Any test which requires a build step is not a unit test and should be
 tested using other means, for example as a validation step during the
 build process.

 == Current Status

 There are two tests that do not pass when running the test suite from the
 `src` directory.

 The first is an error:

 {{{
 1) Tests_Dependencies_Scripts::test_no_source_mapping
 UnexpectedValueException:
 RecursiveDirectoryIterator::__construct(wp/build/): failed to open dir: No
 such file or directory

 wp/tests/phpunit/tests/dependencies/scripts.php:1406
 }}}

 The second is a test failure:

 {{{
 1)
 Tests_Dependencies_Scripts::test_wp_add_inline_script_before_after_concat_with_core_dependency
 Failed asserting that two strings are identical.

 [snip]

 wp/tests/phpunit/includes/abstract-testcase.php:677
 wp/tests/phpunit/tests/dependencies/scripts.php:755
 }}}

 == Tasks

 1. For `Tests_Dependencies_Scripts::test_no_source_mapping`, find a more
 appropriate way to assert that built JS files do not contain a source map
 and remove this PHP unit test.
 2. For
 `Tests_Dependencies_Scripts::test_wp_add_inline_script_before_after_concat_with_core_dependency`
 (ticket #36392), fix the fact that this test expects `.min.js` in its
 output rather than using the return value of `wp_scripts_get_suffix()`.
 3. Increase the reliability of tests which can mess up files if an
 assertion fails (tickets to follow).
 4. Change the default value of `ABSPATH` back to `src` in `wp-config-
 sample.php`.
 5. Investigate whether Travis and/or GitHub Actions should run their tests
 from `src` or `build`.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/51734>
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