feat: Add support for the location hint for a mutation

[theofidry]

Currently infection provides the location hint for test suites, which is the mutated source file. Mutations however, do not have a location hint.

Ideally I think it would make sense to be able to jump to the line where the mutation is applied, the question is what should the location hint look like to be able to achieve this.

[xepozz]

As far as I remember that location is just a regular string where we can put anything, see https://github.com/j-plugins/testo-plugin/blob/main/src/main/kotlin/com/github/xepozz/testo/tests/TestoTestLocator.kt#L51
Also, we can put there two locations:

• where mutation is applied
• what tests was triggered

But I would decide what we do first.
Let's just pass the file path, class FQN and method (if possible) and start/end offsets

[theofidry]

what tests was triggered

I think that would be a lot more tricky. Even for one mutation in theory you might have 10+ tests executed for it.

Let's just pass the file path, class FQN and method (if possible) and start/end offsets

Wouldn't the file path + start/end line + start/end offsets make more sense? (for where the mutation is applied). What should that string look like?

file://<absolute-path>:<startLine>:<startColumn>:<endLine>:<endColumn>
# example:
file:///path/to/project/src/Service/UserService.php:3:15:10:5

Would be alright?

[xepozz]

Let it be like this

##teamcity[
  testStarted 
  name='noAssertions' 
  locationHint='infection:///Users/xepozz/IdeaProjects/j-plugins/testo-plugin/playground/tests/Assert/Feature/CommonTest.php::5-10'
]

:: – delimiter of groups
- – delimiter inside groups

Is it possible to use bytes/chars offset instead of lines+columns?

[theofidry]

So we should use infection:// as the protocol instead of file://? Is it fine that it is not the case for the test suite? (I think it is totally fine, I just want to make sure it is a conscious decision).

Is it possible to use bytes/chars offset instead of lines+columns?

It is.

I initially thought it wasn't because when dumping a PHP-Parser generated AST with its node dumper we only get the lines + column positions, but the values used, startFilePos & endFilePos actually are the desired offsets, the NodeDumper calculates the column position (NodeDumper::toColumn()).

[theofidry]

@xepozz the PR on infection side is ready, just waiting for your validation (see my previous comment)