ci: add automatic PR labeling workflow

.github/workflows/pr-labeler.yml

@@ -0,0 +1,200 @@
+name: PR labeler
+
+on:
+  pull_request_target:
+    types: [opened, edited, ready_for_review, synchronize]
+
+jobs:
+  label:
+    name: Label PR by type
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - name: Apply labels from PR template checkboxes
+        uses: actions/github-script@v7
+        with:
+          script: |
+            // --- Checkbox rules ---
+            const checkboxToLabel = {
+              'Bugfix (a non-breaking change that fixes an issue)': 'bug fix + reliability',
+              'New feature (a non-breaking change that adds functionality)': 'new feature',
+              'Breaking change (a change that causes existing functionality not to work as expected)': 'BREAKING',
+              'Optimization': 'performance is good',
+              'Refactoring': 'refactoring',
+              'Documentation update': 'docs',
+              'Build-related changes': 'build changes',
+            };
+
+            // --- Title prefix rules (conventional commits) ---
+            const prefixToLabel = {
+              'fix': 'bug fix + reliability',
+              'feat': 'new feature',
+              'perf': 'performance is good',
+              'refactor': 'refactoring',
+              'chore': 'minor',
+              'docs': 'docs',
+              'test': 'test',
+              'ci': 'build changes',
+              'build': 'build changes',
+            };
+
+            // --- Path rules ---
+            const pathToLabel = [
+              { pattern: 'src/Nethermind/Nethermind.Optimism', label: 'optimism' },
+              { pattern: 'src/Nethermind/Nethermind.Taiko', label: 'taiko' },
+              { pattern: 'src/Nethermind/Nethermind.Xdc', label: 'XDC' },
+              { pattern: 'src/Nethermind/Nethermind.Network', label: 'network' },
+              { pattern: 'src/Nethermind/Nethermind.Evm', label: 'evm' },
+              { pattern: 'src/Nethermind/Nethermind.Trie', label: 'trie' },
+              { pattern: 'src/Nethermind/Nethermind.State', label: 'state+storage' },
+              { pattern: 'src/Nethermind/Nethermind.Synchronization', label: 'sync' },
+              { pattern: 'src/Nethermind/Nethermind.Db.Rocks', label: 'rocksdb' },
+              { pattern: 'src/Nethermind/Nethermind.Db', label: 'database' },
+              { pattern: 'src/Nethermind/Nethermind.Init/Modules/DbModule.cs', label: 'database' },
+              { pattern: 'src/Nethermind/Nethermind.Runner/configs', label: 'configuration' },
+              { pattern: 'src/Nethermind/Nethermind.Config', label: 'configuration' },
+              { pattern: 'README.md', label: 'docs' },
+              { pattern: 'AGENTS.md', label: 'agentic 🤖' },
+              { pattern: '.github/', label: 'devops' },
+              { pattern: 'Directory.Packages.props', label: 'dependencies' },
+              { pattern: 'tools/', label: 'tools' },
+            ];
+
+            // test label: applied when ALL changed files are in a .Test project
+            const testOnlyLabel = 'test';
+
+            const checkboxLabels = new Set(Object.values(checkboxToLabel));
+            const prefixLabels = new Set(Object.values(prefixToLabel));
+            const pathLabels = new Set(pathToLabel.map(r => r.label));
+            const managedLabels = new Set([...checkboxLabels, ...prefixLabels, ...pathLabels, testOnlyLabel, 'cleanup', 'snap sync']);
+
+            const body = context.payload.pull_request.body || '';
+            const title = context.payload.pull_request.title || '';
+
+            const desiredLabels = new Set();
+
+            // Evaluate checkboxes
+            for (const [text, label] of Object.entries(checkboxToLabel)) {
+              const escaped = text.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+              if (new RegExp(`-\\s*\\[\\s*[xX]\\s*\\]\\s*${escaped}`).test(body)) {
+                desiredLabels.add(label);
+              }
+            }
+
+            // Evaluate "Other" checkbox with keyword matching
+            const otherMatch = body.match(/-\s*\[\s*[xX]\s*\]\s*Other:\s*(.+)/);
+            if (otherMatch) {
+              const otherText = otherMatch[1].toLowerCase();
+              if (/\btest/.test(otherText)) desiredLabels.add('test');
+              if (/\btool/.test(otherText)) desiredLabels.add('tools');
+              if (/\bagent/.test(otherText)) desiredLabels.add('agentic 🤖');
+              if (/\bdoc/.test(otherText)) desiredLabels.add('docs');
+            }
+
+            // Evaluate title prefix: supports "fix:", "fix(scope):", "(fix)", "[fix]"
+            const prefixMatch = title.match(/^[(\[]?(\w+)[)\]]?[\s(:/]/)
+            if (prefixMatch) {
+              const prefix = prefixMatch[1].toLowerCase();
+              if (prefixToLabel[prefix]) {
+                desiredLabels.add(prefixToLabel[prefix]);
+              }
+            }
+
+            // Evaluate title for EIP mentions (eip-1234, EIP 1234, eip1234, etc.)
+            if (/eip[-\s]?\d+/i.test(title)) {
+              desiredLabels.add('eip');
+            }
+
+            // Evaluate title for optimization keyword
+            if (/\boptimiz/i.test(title)) {
+              desiredLabels.add('performance is good');
+            }
+
+            // Evaluate changed file paths
+            const files = await github.paginate(github.rest.pulls.listFiles, {
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: context.issue.number,
+              per_page: 100,
+            });
+
+            for (const { pattern, label } of pathToLabel) {
+              if (files.some(f => f.filename.startsWith(pattern))) {
+                desiredLabels.add(label);
+              }
+            }
+
+            // SnapSync in path
+            if (files.some(f => /SnapSync/i.test(f.filename))) {
+              desiredLabels.add('snap sync');
+            }
+
+            // Dockerfile changes
+            if (files.some(f => /(?:^|\/)[Dd]ockerfile/.test(f.filename))) {
+              desiredLabels.add('devops');
+            }
+
+            // Chain config files with integration keywords
+            const chainKeywordToLabel = {
+              'taiko': 'taiko',
+              'optimism': 'optimism',
+              'op-': 'optimism',
+              'xdc': 'XDC',
+            };
+            for (const f of files) {
+              if (/^src\/Nethermind\/Chains\//.test(f.filename)) {
+                const name = f.filename.toLowerCase();
+                for (const [keyword, label] of Object.entries(chainKeywordToLabel)) {
+                  if (name.includes(keyword)) {
+                    desiredLabels.add(label);
+                  }
+                }
+              }
+            }
+
+            // Apply test label when all changed files are in Test projects
+            if (files.length > 0 && files.every(f => /\.Test[s]?\//.test(f.filename))) {
+              desiredLabels.add(testOnlyLabel);
+            }
+
+            // Apply cleanup label when PR only removes code
+            if (files.length > 0 && files.every(f => f.additions === 0 && f.deletions > 0)) {
+              desiredLabels.add('cleanup');
+            }
+
+            // Diff against current labels
+            const currentLabels = new Set(
+              context.payload.pull_request.labels.map(l => l.name)
+            );
+
+            const toAdd = [...desiredLabels].filter(l => !currentLabels.has(l));
+            const toRemove = [...currentLabels].filter(l => managedLabels.has(l) && !desiredLabels.has(l));
+
+            if (toAdd.length > 0) {
+              await github.rest.issues.addLabels({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number,
+                labels: toAdd,
+              });
+              core.info(`Added labels: ${toAdd.join(', ')}`);
+            }
+
+            for (const label of toRemove) {
+              try {
+                await github.rest.issues.removeLabel({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.issue.number,
+                  name: label,
+                });
+                core.info(`Removed label: ${label}`);
+              } catch (e) {
+                if (e.status !== 404) throw e;
+              }
+            }
+
+            if (toAdd.length === 0 && toRemove.length === 0) {
+              core.info('No label changes needed');
+            }

AGENTS.md

@@ -113,7 +113,7 @@ Before creating a pull request:
   ```bash
   dotnet format whitespace src/Nethermind/ --folder
   ```
-- Use [pull_request_template.md](.github/pull_request_template.md)
+- Follow the [pull_request_template.md](.github/pull_request_template.md) format: fill in the changes section, tick the appropriate type-of-change checkboxes, and complete the testing/documentation sections. The checkboxes drive automatic PR labeling.
 
 ## Prerequisites