Description of problem:

When a Gitlab Merge Request exceeds the Gitlab instance's Diff Limits checks such as "some/path".pathChanged() or files.all.any(f, f.matches(".tekton/")) do not compare against any changed files in excess of the Diff Limit.

Workaround

The only workaround is to split up the Merge Request

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

 # <steps>

• In a repository, write a pipelinerun that triggers on the CEL expression size(files.all) > 3000
• Create a Gitlab Merge request which updates more 3k files
   

  Actual results:

  The pipelinerun is not triggered

  Expected results:

  The pipelinerun is triggered

  Reproducibility (Always/Intermittent/Only Once):

  Always

  Acceptance criteria: 

  The PipelineRun should match and start the pipelinerun

Definition of Done:

Build Details:

Additional info (Such as Logs, Screenshots, etc):

This can be worked around by switching from the MergeRequestDiffs API to using the Repository-Compare API. The consequence though is that the compare API does not page; it sends the entire diff. This may cause memory issues for very large changes. When using the Compare API the comparison should be from the target branch to /refs/merge-requests/<id>/head or the commit sha. The commit sha doesn't "exist" on the repo but appears to still work during comparison.