knip.yml

name: Knip - Unused Code Analysis
on:
  pull_request:
    branches: [main]
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
jobs:
  knip:
    timeout-minutes: 10
    runs-on: ubuntu-24.04
    permissions:
      contents: read
      pull-requests: write
    steps:
      - name: Checkout PR branch
        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1

      - name: Setup node
        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
        with:
          node-version-file: '.nvmrc'
          cache-dependency-path: 'yarn.lock'
          cache: 'yarn'

      - name: Install dependencies
        run: yarn install

      - name: Run Knip on PR branch
        run: yarn knip --reporter json > /tmp/knip-pr.json 2>/dev/null || true

      - name: Checkout main branch
        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
        with:
          ref: main
          clean: false

      - name: Install dependencies (main)
        run: yarn install

      - name: Run Knip on main branch
        run: yarn knip --reporter json > /tmp/knip-main.json 2>/dev/null || true

      - name: Compare results and comment
        uses: actions/github-script@f28e40c7f34bde8b3046d885e986cb6290c5673b # v7.1.0
        with:
          script: |
            const fs = require('fs');

            const issueCategories = [
              'files', 'dependencies', 'devDependencies', 'unlisted',
              'unresolved', 'binaries', 'exports', 'types',
              'enumMembers', 'duplicates'
            ];

            function countIssues(filePath) {
              try {
                const raw = fs.readFileSync(filePath, 'utf8');
                const data = JSON.parse(raw);
                const counts = {};
                // items maps category -> Set of "file:name" identifiers
                const items = {};
                for (const cat of issueCategories) items[cat] = new Set();
                // Top-level "files" are unused files (just strings)
                for (const f of data.files || []) {
                  counts.files = (counts.files || 0) + 1;
                  items.files.add(f);
                }
                for (const issue of data.issues || []) {
                  for (const cat of issueCategories) {
                    if (cat === 'files') continue;
                    if (Array.isArray(issue[cat]) && issue[cat].length > 0) {
                      counts[cat] = (counts[cat] || 0) + issue[cat].length;
                      for (const item of issue[cat]) {
                        items[cat].add(`${issue.file}:${item.name}`);
                      }
                    }
                  }
                }
                let total = 0;
                for (const v of Object.values(counts)) total += v;
                return { counts, total, items };
              } catch (e) {
                console.log(`Failed to parse ${filePath}: ${e.message}`);
                const items = {};
                for (const cat of issueCategories) items[cat] = new Set();
                return { counts: {}, total: 0, items };
              }
            }

            const pr = countIssues('/tmp/knip-pr.json');
            const main = countIssues('/tmp/knip-main.json');

            const categories = [
              ['files', 'Unused files'],
              ['dependencies', 'Unused dependencies'],
              ['devDependencies', 'Unused devDependencies'],
              ['unlisted', 'Unlisted dependencies'],
              ['unresolved', 'Unresolved imports'],
              ['binaries', 'Unlisted binaries'],
              ['exports', 'Unused exports'],
              ['types', 'Unused exported types'],
              ['enumMembers', 'Unused enum members'],
              ['duplicates', 'Duplicate exports'],
            ];

            const diff = pr.total - main.total;
            const emoji = diff > 0 ? '🔴' : diff < 0 ? '🟢' : '⚪';
            const sign = diff > 0 ? '+' : '';

            let body = `## Knip - Unused Code Analysis\n\n`;

            if (diff === 0) {
              body += `${emoji} No changes detected (${main.total} issues on both main and PR)\n`;
            } else {
              body += `${emoji} **${sign}${diff}** change in total issues (${main.total} on main → ${pr.total} on PR)\n\n`;
              body += `| Category | main | PR | Diff |\n`;
              body += `|----------|-----:|---:|-----:|\n`;

              const detailLines = [];
              for (const [key, label] of categories) {
                const mainCount = main.counts[key] || 0;
                const prCount = pr.counts[key] || 0;
                const catDiff = prCount - mainCount;
                if (mainCount === 0 && prCount === 0) continue;
                const catSign = catDiff > 0 ? '+' : '';
                const catEmoji = catDiff > 0 ? ' 🔴' : catDiff < 0 ? ' 🟢' : '';
                body += `| ${label} | ${mainCount} | ${prCount} | ${catSign}${catDiff}${catEmoji} |\n`;

                if (catDiff !== 0) {
                  const added = [...pr.items[key]].filter(x => !main.items[key].has(x));
                  const removed = [...main.items[key]].filter(x => !pr.items[key].has(x));
                  if (added.length || removed.length) {
                    detailLines.push(`**${label}**`);
                    for (const a of added) detailLines.push(`- 🔴 \`${a}\``);
                    for (const r of removed) detailLines.push(`- 🟢 ~\`${r}\`~`);
                  }
                }
              }

              if (detailLines.length) {
                body += `\n<details><summary>Details</summary>\n\n`;
                body += detailLines.join('\n') + '\n';
                body += `</details>\n`;
              }
            }

            body += `\n<details><summary>What is this?</summary>\n\n`;
            body += `[Knip](https://knip.dev) finds unused files, dependencies, and exports in your codebase.\n`;
            body += `This comment compares the PR branch against \`main\` to detect regressions.\n\n`;
            body += `Run \`yarn knip\` locally to see full details.\n`;
            body += `</details>\n`;

            // Find existing comment
            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
            });
            const existing = comments.find(c =>
              c.user.type === 'Bot' && c.body.includes('Knip - Unused Code Analysis')
            );

            if (existing) {
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existing.id,
                body,
              });
            } else {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
                body,
              });
            }