no new @ts-nocheck

Checks if new @ts-nocheck is introduced in a PR or not.

• It compares the pull request's current HEAD against the merge-base with the destination branch
• It searches for the patterns // @ts-nocheck or /* @ts-nocheck in added/removed lines
• Then, it separates out the additions and deletions and counts the instances in each of them
• Finally, it would fail with exit 1 if the count in additions is more than count in deletions (which would mean the PR has introduced new @ts-nocheck instances)

How it works

The action searches for lines containing either:

• // @ts-nocheck - line comment pattern
• /* @ts-nocheck - block comment pattern

Lines can have other content before or after these patterns. The check ignores plain @ts-nocheck without comment markers.

The action fetches the base branch ref it needs before computing the merge-base, which avoids false positives when the PR branch is behind the base branch.

Tests

Run the regression tests locally with:

node tests/diff_test.ts