QA improve checks (#1969)

* chore(dev-deps): size-limit and es-checks

* chore(size-limit): initial setup

* ci: initial github ci workflow

* fix: lint

* chore(es-check): add exclusions, check for browser es2017

* chore(size-limit): fix node imports in webpack mode

* chore(scripts): bundle analyzer command

.github/workflows/ci.yml

@@ -0,0 +1,48 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [14.x, 16.x]
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: 'npm'
+
+      - name: 📥 Install
+        run: npm install
+
+      - name: ESLint checks
+        run: npm run lint
+
+      - name: Unit tests
+        run: npm test
+
+      - name: E2E tests
+        run: npm run test:e2e
+
+      - name: Build next-i18next
+        run: npm run build
+
+      - name: Check dist for ecmascript compliance
+        run: npm run check-dist
+
+      - name: Check size limits
+        run: npm run check-size
+

.size-limit.cjs

@@ -0,0 +1,39 @@
+// @ts-check
+
+const fullEsmMaxSize = "23KB";
+const fullCjsMaxSize = "46KB";
+
+const modifyWebpackConfig = config => {
+  config.resolve = {};
+  config.resolve.fallback = { "path": false, "fs": false };
+}
+
+/**
+ * Will ensure esm tree-shakeability and total size are within expectations.
+ *
+ * @link https://github.com/ai/size-limit/
+ * @type {{name: string, path: string[], limit: string, import?: string, webpack?: boolean, modifyWebpackConfig: any}[]}
+ */
+module.exports = [
+  // ###################################################
+  // ESM full bundle
+  // ###################################################
+  {
+    name: "ESM (import everything *)",
+    path: ["dist/esm/index.js"],
+    import: "*",
+    limit: fullEsmMaxSize,
+    modifyWebpackConfig,
+  },
+  // ###################################################
+  // Commonjs full bundle
+  // ###################################################
+  {
+    name: "CJS (require everything *)",
+    path: ["dist/commonjs/index.js"],
+    import: "*",
+    webpack: true,
+    limit: fullCjsMaxSize,
+    modifyWebpackConfig,
+  }
+];

package.json

@@ -64,7 +64,12 @@
     "contributors:generate": "all-contributors generate",
     "preversion": "npm run test && npm run build && git push",
     "postversion": "git push && git push --tags && npm run release",
-    "release": "gh-release"
+    "release": "gh-release",
+    "check-size": "size-limit",
+    "analyze-size:why": "size-limit --why",
+    "check-dist": "run-s check-dist:*",
+    "check-dist:browser-cjs": "es-check --not 'dist/**/*.map.js,dist/commonjs/createClient/package.json,dist/commonjs/**node**.js,dist/commonjs/serverSideTranslations.js' -v es2017 './dist/commonjs/**/*'",
+    "check-dist:browser-esm": "es-check --not 'dist/**/*.map.js,dist/esm/createClient/package.json,dist/**node**.js,dist/esm/serverSideTranslations.js' -v es2017 --module './dist/esm/**/*'"
   },
   "husky": {
     "hooks": {
@@ -93,6 +98,9 @@
     "@babel/preset-env": "^7.18.10",
     "@babel/preset-react": "^7.18.6",
     "@babel/preset-typescript": "^7.18.6",
+    "@size-limit/file": "^8.1.0",
+    "@size-limit/webpack": "^8.1.0",
+    "@size-limit/webpack-why": "8.1.0",
     "@testing-library/react": "^13.3.0",
     "@types/i18next-fs-backend": "^1.1.2",
     "@types/jest": "^28.1.7",
@@ -108,6 +116,7 @@
     "babel-plugin-transform-async-to-generator": "^6.24.1",
     "bundlesize": "^0.18.1",
     "cypress": "^9.1.1",
+    "es-check": "^7.0.1",
     "eslint": "^8.22.0",
     "eslint-plugin-cypress": "^2.12.1",
     "eslint-plugin-import": "^2.26.0",
@@ -119,10 +128,13 @@
     "husky": "^3.0.0",
     "jest": "^26.6.3",
     "next": "^12.2.5",
+    "npm-run-all": "^4.1.5",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "start-server-and-test": "^1.14.0",
-    "typescript": "^4.7.4"
+    "typescript": "^4.7.4",
+    "size-limit": "8.1.0",
+    "webpack": "5.74.0"
   },
   "dependencies": {
     "@babel/runtime": "^7.18.9",