[SPIKE] Collecting performance information

.github/workflows/actions/build-dist/action.yml

@@ -0,0 +1,30 @@
+name: Build `dist`
+
+runs:
+  using: composite
+
+  steps:
+    - name: Cache build
+      uses: actions/cache@v3
+      id: build-cache
+
+      with:
+        # Restore build cache (unless commit SHA changes)
+        key: build-dist-cache-${{ github.sha }}
+        path: |
+          dist
+
+    - name: Install dependencies
+      uses: ./.github/workflows/actions/install-node
+
+      # Skip install when build is already cached
+      if: steps.build-cache.outputs.cache-hit != 'true'
+
+    - name: Build
+      id: build
+
+      # Skip build when we’ve built this SHA before
+      if: steps.build-cache.outputs.cache-hit != 'true'
+      shell: bash
+
+      run: npm run build:dist

.github/workflows/actions/build-package/action.yml

@@ -0,0 +1,30 @@
+name: Build package
+
+runs:
+  using: composite
+
+  steps:
+    - name: Cache build
+      uses: actions/cache@v3
+      id: build-cache
+
+      with:
+        # Restore build cache (unless commit SHA changes)
+        key: build-package-cache-${{ github.sha }}
+        path: |
+          package
+
+    - name: Install dependencies
+      uses: ./.github/workflows/actions/install-node
+
+      # Skip install when build is already cached
+      if: steps.build-cache.outputs.cache-hit != 'true'
+
+    - name: Build
+      id: build
+
+      # Skip build when we’ve built this SHA before
+      if: steps.build-cache.outputs.cache-hit != 'true'
+      shell: bash
+
+      run: npm run build:compile

.github/workflows/actions/install-node/action.yml

@@ -13,7 +13,7 @@ runs:
         key: npm-install-cache-${{ hashFiles('package-lock.json', '**/package.json') }}
         path: |
           .cache/puppeteer
-          node_modules
+          **/node_modules
 
     - name: Setup Node.js
       uses: ./.github/workflows/actions/setup-node

.github/workflows/tests.yml

@@ -11,6 +11,9 @@ on:
 
   workflow_dispatch:
 
+permissions:
+  pull-requests: write
+
 concurrency:
   group: tests-${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
@@ -126,14 +129,6 @@ jobs:
 
       matrix:
         include:
-          - description: Verify package build
-            name: test-build-package
-            run: npm run build:package
-
-          - description: Verify distribution build
-            name: test-build-dist
-            run: npm run build:dist
-
           - description: JavaScript behaviour tests
             name: test-behaviour
             run: npx jest --color --maxWorkers=2 --selectProjects "JavaScript behaviour tests"
@@ -172,3 +167,73 @@ jobs:
 
     # Skip when secrets are unavailable on forks
     if: ${{ github.repository_owner == 'alphagov' }}
+
+  build_dist:
+    name: Build dist
+    needs: [install]
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Restore dependencies
+        uses: ./.github/workflows/actions/install-node
+
+      - name: Build dist
+        uses: ./.github/workflows/actions/build-dist
+
+  build_package:
+    name: Build package
+    needs: [install]
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Restore dependencies
+        uses: ./.github/workflows/actions/install-node
+
+      - name: Build package
+        uses: ./.github/workflows/actions/build-package
+
+  stats:
+    name: Stats
+    needs: [build_dist,build_package]
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Restore dependencies
+        uses: ./.github/workflows/actions/install-node
+
+      - name: Restore dist
+        uses: ./.github/workflows/actions/build-dist
+
+      - name: Restore package
+        uses: ./.github/workflows/actions/build-package
+
+      - name: Collects stats
+        run: npm start --workspace stats
+
+      - name: Save stats
+        uses: actions/upload-artifact@v3
+        with:
+          name: File stats
+          path: stats/public/all/stats-sunburst.html
+          if-no-files-found: ignore
+
+      - name: Add comment to PR
+        uses: actions/github-script@v6
+        with:
+          github-token: ${{secrets.GITHUB_TOKEN}}
+          script: |
+            const commentOnPr = require('./stats/comment-on-pr.js');
+            await commentOnPr({github,context})
+
+        if: github.event_name == 'pull_request'
+
+

app/app.js

@@ -84,6 +84,7 @@ module.exports = async (options) => {
   app.use(middleware.assets)
   app.use('/docs', middleware.docs)
   app.use('/vendor', middleware.vendor)
+  app.use('/stats', middleware.stats)
 
   // Turn form POSTs into data that can be used for validation.
   app.use(bodyParser.urlencoded({ extended: true }))

app/middleware/index.js

@@ -3,10 +3,12 @@
  */
 const assets = require('./assets')
 const docs = require('./docs')
+const stats = require('./stats')
 const vendor = require('./vendor')
 
 module.exports = {
   assets,
   docs,
-  vendor
+  vendor,
+  stats
 }

app/middleware/stats.js

@@ -0,0 +1,12 @@
+const express = require('express')
+const serveIndex = require('serve-index')
+
+const configPaths = require('../../config/paths')
+const router = express.Router()
+
+// Serve the files themselves
+router.use(express.static(configPaths.stats))
+// Serve the directory listings, to allow navigating to the files
+router.use(serveIndex(configPaths.stats))
+
+module.exports = router

app/package.json

@@ -28,6 +28,7 @@
     "minimatch": "^5.1.1",
     "nodemon": "^2.0.20",
     "nunjucks": "^3.2.3",
+    "serve-index": "^1.9.1",
     "shuffle-seed": "^1.1.6"
   },
   "devDependencies": {

config/paths.js

@@ -24,7 +24,10 @@ const configPaths = {
 
   // Documentation
   jsdoc: join(rootPath, 'jsdoc'),
-  sassdoc: join(rootPath, 'sassdoc')
+  sassdoc: join(rootPath, 'sassdoc'),
+
+  // Performance
+  stats: join(rootPath, 'stats', 'public')
 }
 
 module.exports = {

package.json

@@ -17,7 +17,7 @@
     "postinstall": "npm ls --depth=0",
     "start": "gulp dev",
     "serve": "npm run serve --workspace app",
-    "heroku": "npm run build:compile && npm start --workspace app",
+    "heroku": "npm run build:compile && npm start --workspace stats && npm start --workspace app",
     "build-release": "./bin/build-release.sh",
     "publish-release": "./bin/publish-release.sh",
     "pre-release": "./bin/pre-release.sh",