[10.x] Fixes memory leak on anonymous migrations

[nunomaduro]

This pull request fixes a memory leak on Laravel test suites that are using anonymous migrations.

// Work in progress.

// Before:
Time: 00:39.915, Memory: 324.00 MB

// After
Time: 00:37.882, Memory: 40.00 MB

Fixes #46029.

[miki131]

static::$requiredMigrations[$file] ??= $this->files->requireOnce($file);

Try this instead of IF

[donnysim]

I wonder if php will ever fix the anonymous global function memory leaking 🙃

[dbohn]

If I remember correctly, require_once only returns true if the file was successfully required and does not return the return value of the file. That might be unintended at this stage

[dbohn]

Thank you for looking into this so quickly!
I noticed, that there is no logic in place to reset the state of the migration class. Is this intentional or still WIP?
This might be a breaking change (as there probably are devs relying on this when running their tests), which might be why it's targeted to v10 :-)

[rojtjo]

I noticed, that there is no logic in place to reset the state of the migration class. Is this intentional or still WIP?

This can be fixed by cloning the cached migration before returning it. I've tested this using your (@dbohn) example repository and the memory seems to remain the same.

This would mean that this pull request could actually target the 9.x branch.

// without clone
Time: 01:29.299, Memory: 38.00 MB

// with clone
Time: 01:29.864, Memory: 38.00 MB

[nunomaduro]

@rojtjo Excellent idea. Going to update the pull request.

[nunomaduro]

Replaced by #46073.