impactifier.yml

name: Impactifier CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

permissions:
  contents: read
  issues: write
  pull-requests: write

jobs:
  impactifier:
    runs-on: ubuntu-latest

    steps:
      # 1. Checkout the repository with full history
      - name: Checkout Repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0  # Fetch all history for all branches

      # 2. Cache Cargo Registry
      - name: Cache Cargo Registry
        uses: actions/cache@v3
        with:
          path: ~/.cargo/registry
          key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-registry-

      # 3. Cache Cargo Build
      - name: Cache Cargo Build
        uses: actions/cache@v3
        with:
          path: target
          key: ${{ runner.os }}-cargo-build-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-build-

      # 4. Build Impactifier
      - name: Build Impactifier
        run: |
          cargo build --release --manifest-path Cargo.toml

      # 5. Run Impactifier and generate diff.json
      - name: Run Impactifier
        id: run_impactifier
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          ./target/release/impactifier --tracing-level=0 --from-branch=main --to-branch=main

      # 6. (Optional) Output diff.json for debugging
      - name: Output diff.json (Debug)
        if: ${{ github.event_name == 'pull_request' }}
        run: |
          cat diff.json

      # 7. Post Comment on Pull Request with the diff
      - name: Post Comment on Pull Request
        if: github.event_name == 'pull_request'
        uses: actions/github-script@v6
        with:
          script: |
            const fs = require('fs');
            const path = 'diff.json'; // Path to the diff JSON file

            // Check if the diff file exists
            if (!fs.existsSync(path)) {
              console.log('No diff.json file found.');
              return;
            }

            // Read and parse the diff JSON
            let diffData;
            try {
              const rawData = fs.readFileSync(path, 'utf8');
              diffData = JSON.parse(rawData);
            } catch (error) {
              console.error('Failed to read or parse diff.json:', error);
              return;
            }

            // Format the diff for the comment
            let formattedDiff = '';
            if (diffData.deltas && Array.isArray(diffData.deltas)) {
              diffData.deltas.forEach(delta => {
                if (delta.value) {
                  // Escape backticks in the delta.value to prevent breaking the Markdown
                  const safeValue = delta.value.replace(/`/g, '\\`');
                  formattedDiff += `${safeValue}\n`;
                }
              });
            } else {
              formattedDiff = 'No differences found.';
            }

            // Handle large diffs by truncating (optional)
            const maxLength = 60000; // GitHub comment limit
            let truncatedDiff = formattedDiff;
            if (formattedDiff.length > maxLength) {
              truncatedDiff = formattedDiff.substring(0, maxLength) + '\n... (diff truncated)';
            }

            // Create a summary based on the number of deltas
            let summary = '';
            if (diffData.deltas && diffData.deltas.length > 0) {
              summary = `**Total Changes:** ${diffData.deltas.length} file(s) changed.\n\n`;
            } else {
              summary = 'No changes detected between the specified branches.\n\n';
            }

            // Create the comment body with summary and diff
            const commentBody = `## Impactifier Report

            ${summary}

            \`\`\`diff
            ${truncatedDiff}
            \`\`\``;

            // Post the comment to the pull request
            try {
              await github.rest.issues.createComment({
                issue_number: context.issue.number,
                owner: context.repo.owner,
                repo: context.repo.repo,
                body: commentBody
              });
              console.log('Impactifier report posted successfully.');
            } catch (error) {
              console.error('Failed to post Impactifier report:', error);
            }