Function getPRDiffRanges

code-scan-action/src/github.ts:103–123

* Fetch PR diff and extract valid line ranges for each file. * This is used to validate and clamp comment line numbers.

(
  octokit: Octokit,
  context: PullRequestContext,
)

 * This is used to validate and clamp comment line numbers.
 */
async function getPRDiffRanges(
  octokit: Octokit,
  context: PullRequestContext,
): Promise<FileLineRanges> {
  try {
    const { data: diff } = await octokit.pulls.get({
      owner: context.owner,
      repo: context.repo,
      pull_number: context.number,
      mediaType: { format: 'diff' },
    });

    // The diff is returned as a string when using mediaType: { format: 'diff' }
    return extractValidLineRanges(diff as unknown as string);
  } catch (error) {
    core.warning(
      `Failed to fetch PR diff for line validation: ${error instanceof Error ? error.message : String(error)}`,
    );
    return new Map();
  }
}

/**
 * Clamp a comment's line numbers to valid diff ranges.