ai-code-review.yml

name: "Code Review by Gemini AI"
on:
  issue_comment:
    types:
      - created
      - updated

jobs:
  review:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
      issues: read
    steps:
      - uses: actions/checkout@v3

      - name: Only PR comments
        if: ${{ !github.event.issue.pull_request || !contains(github.event.comment.body,'!ai') }}
        run: exit 1

      - name: Put a reaction to the comment
        run: gh api graphql --silent --raw-field query="mutation AddReaction {addReaction(input:{subjectId:\"$NODE_ID\",content:EYES}){reaction{content}subject{id}}}"
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          NODE_ID: ${{ github.event.comment.node_id }}

      - name: Fetch filtered PR diff (only .ts, .tsx, .sol files)
        id: pr-diff
        uses: actions/github-script@v6
        with:
          script: |
            const pr_number = context.payload.issue.number;
            const pr = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: pr_number
            });
            const { data: diff } = await github.request('GET /repos/{owner}/{repo}/pulls/{pull_number}', {
              headers: {
                accept: 'application/vnd.github.v3.diff'
              },
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: pr_number
            });

            // Initialize variables to store filtered diff and a flag for capturing lines
            let filteredDiff = '';
            let capture = false;

            // Iterate over each line in the diff
            diff.split('\n').forEach(line => {
              // Check if the line is a diff line for the relevant file types
              if (line.startsWith('diff --git')) {
                capture = line.endsWith('.ts') || line.endsWith('.tsx') || line.endsWith('.sol');
              }
              // If capturing, append the current line to the filtered diff
              if (capture) {
                filteredDiff += line + '\n';
              }
            });

            // Get the head commit SHA
            const headSha = pr.data.head.sha;

            // Set outputs for the filtered diff and head SHA
            core.setOutput("diff", filteredDiff);
            core.setOutput("headSha", headSha);

      - name: Log filtered diff to file
        id: log-diff
        continue-on-error: true
        run: |
          echo "${{ steps.pr-diff.outputs.diff }}"

      - uses: rubensflinco/gemini-code-review-action@1.0.5
        name: "Code Review by Gemini AI"
        id: review
        with:
          gemini_api_key: ${{ secrets.GEMINI_API_KEY }}
          github_token: ${{ secrets.GITHUB_TOKEN }}
          github_repository: ${{ github.repository }}
          github_pull_request_number: ${{ github.event.issue.number }}
          git_commit_hash: ${{ steps.pr-diff.outputs.headSha }}
          model: "gemini-1.5-pro-latest"
          pull_request_diff: |-
            ${{ steps.pr-diff.outputs.diff }}
          pull_request_chunk_size: "5000"
          extra_prompt: |-
            Make a pull request review in regards of the added and removed code.
            Start with a summary of the changes and then list detail the review and suggestions.
            Focus on code quality, security, performance, best practices and potential mistakes.
            Never ask to provide more code and only review the code you received even if its partial.
            When a line start with a minus (`-`) it means that the line was removed, when it starts with plus (`+`) it means that the line was added.
          log_level: "DEBUG"

      - name: Add thumbs down reaction if something went wrong
        if: steps.review.outcome == 'failure'
        run: gh api graphql --silent --raw-field query="mutation AddReaction {addReaction(input:{subjectId:\"$NODE_ID\",content:THUMBS_DOWN}){reaction{content}subject{id}}}"
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          NODE_ID: ${{ github.event.comment.node_id }}

      - name: Get Gemini step log
        if: steps.review.outcome == 'failure'
        id: get-gemini-log
        run: |
          echo "gemini_log<<EOF" >> $GITHUB_OUTPUT
          gh run view ${{ steps.review.outputs.run_id }} --log >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT

      - name: Add comment with log
        if: steps.review.outcome == 'failure'
        uses: actions/github-script@v6
        with:
          script: |
            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: 'Gemini Code Review encountered an error. Here is the step log:\n\n```\n${{ steps.get-gemini-log.outputs.gemini_log }}\n```'
            });