Add issue linkage tracking to PR analysis reports using GitHub GraphQL API

[Copilot]

• Add linkedIssue field to PullRequestAnalysis interface (number | null)
• Create utility function to extract issue numbers from PR body text REMOVED
• Modify GitHubService.analyzePullRequest() to detect linked issues IMPROVED
• Use GitHub GraphQL API closingIssuesReferences field instead of parsing PR body
• Update README documentation to show the new field in sample output
• Test the changes with GraphQL implementation
• Build and lint to ensure no regressions
• Fix code formatting issues with Prettier

Summary of Changes

Replaced the PR body parsing approach with GitHub's GraphQL API as suggested in the code review comments. This is much more reliable and comprehensive:

What Changed

• Removed extractLinkedIssue() function that used regex to parse PR descriptions
• Added getLinkedIssues() method that uses GitHub GraphQL API
• Modified analyzePullRequest() to call the GraphQL API alongside other data fetching
• Fixed code formatting issues with Prettier

Benefits of GraphQL Approach

• ✅ More reliable: Uses GitHub's native issue linking detection
• ✅ Comprehensive: Captures issues linked via keywords AND manual UI linking
• ✅ Handles edge cases: No regex parsing means fewer false positives/negatives
• ✅ Future-proof: Automatically benefits from GitHub's linking improvements

GraphQL Query Used

query($owner: String!, $repo: String!, $number: Int!) {
  repository(owner: $owner, name: $repo) {
    pullRequest(number: $number) {
      closingIssuesReferences(first: 1) {
        nodes {
          number
        }
      }
    }
  }
}

The linkedIssue field now contains the first closing issue number from GitHub's native closingIssuesReferences, or null if no issues will be closed by the PR.

All linting and formatting checks now pass successfully.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Each PR description should record that PR is linked to an issue</issue_title>
<issue_description>If the PR is linked to an issue, the issue number should be given. Otherwise it should be null.</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #4

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[ChrisTimperley]

Let's double check to see whether we can use the GraphQL to solve this problem rather than trying to parse the body of the PR.

[ChrisTimperley]

Does the GitHub GraphQL API not automatically expose this information?

[ChrisTimperley]

@copilot can you take a look into this?

[Copilot]

Yes, the GitHub GraphQL API has a closingIssuesReferences field that automatically exposes linked issues. This is much better than parsing PR body text as it captures both keyword-based links and manual UI linking. I'll switch to using GraphQL for this.

[Copilot]

Let's double check to see whether we can use the GraphQL to solve this problem rather than trying to parse the body of the PR.

You're absolutely right! The GitHub GraphQL API has a closingIssuesReferences field that provides this information directly without needing to parse PR body text. This would be much more reliable and would capture issues linked through both keywords and the GitHub UI. I'll implement this GraphQL-based approach.

[ChrisTimperley]

@copilot Overall, this looks great. Just fix up the linting issue (you need to format the code) and we're good to merge.

[Copilot]

@copilot Overall, this looks great. Just fix up the linting issue (you need to format the code) and we're good to merge.

Fixed the code formatting with Prettier. The issue was a long line that needed to be broken up. All linting and formatting checks now pass. (commit: ef5c3c0)