Allow to run only certain test methods

This have been on my wish list for ages.

Based on a rudimentary review and test, this looks good.

A style nit:

+function simpletest_run_tests(array $test_list, $reporter = 'drupal', array $failed_methods = array()) {

I think $failed_methods should rather be named something like $test_methods—whether they failed in the last test run is not really relevant for the current test run (and I guess you could imagine other cases where you want to run only a specific test function).

I think would be more intuitive if the method array immediately followed the test array in function argument lists, or perhaps the two could be merged into one array like array('class1' => TRUE, 'class2' => array('testFoo')) (meaning run everything in class1 but only testFoo() in class2). I think this will make the new feature more like an integrated part of the API.

The preg_match does not work with code like this:

  function testFoo() {
    $this->bar();
    $this->assertTrue(TRUE);
  }
  function bar() {
    $divide_by_zero = 1 / 0;
  }

When I try to run the failed test, it completes a test run with no tests (I think) and ends up with this error message:

Error message
No test results to display.

       'fail' => t('Fail (@count)', array('@count' => count($filter['fail']))),
+      'fail_methods' => t('Failed methods only (@count)', array('@count' => count($failed_methods))),

These counts are not really comparable. I wonder whether it would be better to show e.g. “Classes with failing tests (3 classes)” and “Methods with failing tests (4 methods in 3 classes)”. In fact I think the current wording is rather confusing, because it is not obvious what the numbers refer to.

Interesting.

This looks like a low-impact change that could bring a lot of benefits and help with spreading TDD in Drupal. Agreed with not changing around the UI at this stage.

when retesting it could be that other changes in core affected several other testcases. So you cannot ensure you covered everything just by doing a retest on the test that failed previously.
(for example when there is to much time between a test and a retest)

You have to take care of that too.

I tested this by hardcoding some arguments for run().

Might be good to provide an example of how this is supposed to be used when writing tests.

I doubt this is easier than commenting out some test functions but maybe I fail to see the use case.

Let's be more explicit about how this improves our lives.

Sounds like Dries's comment can be summarized as "needs more documentation", thus needs work.

I've just committed a test-run command to drush and at sun's suggestion, I've added support for this fine new parameter. So, we now have our use case committed and value has been proven IMO. Agree with RTBC.

I think a module that exposed a UI for this would be a complete and absolute nightmare, but the drush application has quite a few uses. Someone could set up their own "testbot lite" that just runs the most critical test cases for the major business logic of their Drupal site. Or even for run-of-the-mill core developers, to just hit up + drush test FooWhateverKeepsBreakingTestCase as they're drilling into a patch.

However, the "needs documentation" issue in #12/#13 still hasn't been addressed. In other words, there are details in this issue that aren't remotely hinted at in the code. Let's get some "why" stuff in there. Maybe something like:

+   * @param $methods
+   *   (optional) A list of class method names to run in the form of XXXXXXXX. By default, all methods
+   *   of the class are taken into account, but it can be useful to call only one
or a few test cases at a time for debugging purposes.

Note that only methods starting with
+   *   "test" are executed.

(Obviously, with the formatting vastly cleaned up :P)

And this seems more like an API addition than an API change; there's nothing existing test authors need to adjust.

Fixed a typo ("unless a specific list" instead of "unless as specific list")

OK, the extra documentation is helpful. Committed to CVS HEAD.