Modernize frontend foundations and tooling

.babelrc

@@ -1,4 +1,12 @@
 {
-    "presets": [["@babel/preset-env", { "targets": { "browsers": ["ie >= 11", "safari > 9"] } }], "@babel/preset-react", "@babel/preset-typescript"],
-    "plugins": ["react-hot-loader/babel", "@babel/plugin-proposal-class-properties", "transform-optional-chaining"]
+    "presets": [
+        [
+            "@babel/preset-env",
+            {
+                "targets": "> 0.5%, last 2 versions, Firefox ESR, not dead"
+            }
+        ],
+        ["@babel/preset-react", { "runtime": "automatic" }],
+        "@babel/preset-typescript"
+    ]
 }

.circleci/config.yml

@@ -1,38 +1,55 @@
-# Javascript Node CircleCI 2.0 configuration file
-#
-# Check https://circleci.com/docs/2.0/language-javascript/ for more details
-#
-version: 2
+version: 2.1
+
 jobs:
-  build:
-    docker:
-      # specify the version you desire here
-      - image: circleci/node:7.10
-
-      # Specify service dependencies here if necessary
-      # CircleCI maintains a library of pre-built images
-      # documented at https://circleci.com/docs/2.0/circleci-images/
-      # - image: circleci/mongo:3.4.4
-
-    working_directory: ~/repo
-
-    steps:
-      - checkout
-
-      # Download and cache dependencies
-      - restore_cache:
-          keys:
-          - v1-dependencies-{{ checksum "package.json" }}
-          # fallback to using the latest cache if no exact match is found
-          - v1-dependencies-
-
-      - run: yarn install
-
-      - save_cache:
-          paths:
-            - node_modules
-          key: v1-dependencies-{{ checksum "package.json" }}
-
-      # run tests!
-      - run: yarn test
+    build:
+        docker:
+            - image: cimg/node:24.18.0
+
+        working_directory: ~/repo
+
+        steps:
+            - checkout
+
+            - run:
+                  name: Pin Yarn
+                  command: |
+                      corepack enable
+                      corepack prepare yarn@1.22.22 --activate
+
+            - restore_cache:
+                  keys:
+                      - v2-yarn-{{ checksum "package.json" }}-{{ checksum "yarn.lock" }}
+                      - v2-yarn-
+
+            - run:
+                  name: Install dependencies
+                  command: yarn install --frozen-lockfile
+
+            - save_cache:
+                  key: v2-yarn-{{ checksum "package.json" }}-{{ checksum "yarn.lock" }}
+                  paths:
+                      - ~/.cache/yarn
+
+            - run:
+                  name: Test
+                  command: yarn test
+
+            - run:
+                  name: Quality ratchets
+                  command: yarn quality
+
+            - run:
+                  name: Production build
+                  command: |
+                      mkdir -p /tmp/build-reports
+                      yarn build 2>&1 | tee /tmp/build-reports/build-output.txt
+
+            - run:
+                  name: Report artifact size
+                  command: |
+                      node scripts/bundle-report.mjs --out /tmp/build-reports/bundle-report.json
+                      cat /tmp/build-reports/bundle-report.json
 
+            - store_artifacts:
+                  path: /tmp/build-reports
+                  destination: build-reports

.github/workflows/frontend.yml

@@ -0,0 +1,56 @@
+name: Frontend verification
+
+on:
+    pull_request:
+    push:
+        branches:
+            - master
+    workflow_dispatch:
+
+concurrency:
+    group: frontend-${{ github.workflow }}-${{ github.ref }}
+    cancel-in-progress: true
+
+jobs:
+    verify:
+        runs-on: ubuntu-latest
+        timeout-minutes: 20
+
+        steps:
+            - name: Check out repository
+              uses: actions/checkout@v7
+
+            - name: Set up Node.js
+              uses: actions/setup-node@v7
+              with:
+                  node-version-file: .nvmrc
+
+            - name: Pin Yarn
+              run: |
+                  corepack enable
+                  corepack prepare yarn@1.22.22 --activate
+
+            - name: Install dependencies
+              run: yarn install --frozen-lockfile
+
+            - name: Install Chromium
+              run: yarn playwright install --with-deps chromium
+
+            - name: Run frontend tests
+              run: yarn test
+
+            - name: Run quality ratchets
+              run: yarn quality
+
+            - name: Validate performance harness
+              if: ${{ hashFiles('scripts/performance/experience-*.test.mjs') != '' }}
+              run: yarn test:performance
+
+            - name: Build production assets
+              run: yarn build
+
+            - name: Report bundle and precache sizes
+              run: yarn analyze:bundle
+
+            - name: Run browser and offline journeys
+              run: yarn test:e2e

.nvmrc

@@ -0,0 +1 @@
+24.18.0

Dockerfile

@@ -1,16 +1,15 @@
-FROM node:10-alpine
+FROM node:24-alpine
 
-# Create app directory
 WORKDIR /usr/src/app
 
-COPY yarn.lock ./
-COPY package*.json ./
+RUN corepack enable
 
-RUN yarn
+COPY package.json yarn.lock ./
+RUN yarn install --frozen-lockfile
 
 COPY . .
 
 RUN yarn build
 
 EXPOSE 80
-ENTRYPOINT yarn serve
+CMD ["yarn", "serve"]