Bisect list of files within a large commit

bisect.ps1

$files = git diff --name-only main

# Binary search for a file that causes `./test/runner other.test_closure_type_annotations` to fail.
# At each step, try to revert half of the files to `main` branch.
# In the end $files will contain only the files that cause the test to fail.
while ($files.Length -gt 1) {
	Write-Output "Testing $($files.Length) files:"
	$files | ForEach-Object { Write-Output "  $_" }

	$mid = [math]::floor($files.Length / 2)
	$lower = $files[0..($mid - 1)]
	$upper = $files[$mid..$files.Length]
	git checkout main -- $lower
	git checkout -- $upper
	./test/runner other.test_closure_type_annotations
	if ($?) {
		git checkout -- $lower
		git checkout main -- $upper
		./test/runner other.test_closure_type_annotations
		if ($?) {
      # If both variants succeeded, we're splitting incorrectly - there's a dependency between files.
      # Shuffle them and try again.
			$files = $files | Sort-Object {Get-Random}
		} else {
			$files = $lower
		}
	} else {
		$files = $upper
	}
	git reset --hard
}

# Print the file that causes the test to fail.
$files