adobecom · raissanjay · Sep 25, 2025 · Sep 29, 2025
diff --git a/babel.config.js b/babel.config.js
@@ -0,0 +1,14 @@
+module.exports = {
+  presets: [
+    [
+      '@babel/preset-env',
+      { targets: { node: 'current' }, modules: 'commonjs' },
+    ],
+    ['@babel/preset-react', { runtime: 'classic' }],
+  ],
+  plugins: [
+    ['@babel/plugin-transform-class-properties', { loose: true }],
+    ['@babel/plugin-transform-object-rest-spread', { loose: true }],
+  ],
+};
+
diff --git a/jest.a11y.config.js b/jest.a11y.config.js
@@ -0,0 +1,20 @@
+// Hermetic Jest config for a11y tests only
+module.exports = {
+  rootDir: __dirname,
+  displayName: 'a11y',
+  testEnvironment: 'jsdom',
+  testRunner: 'jest-circus/runner',
+  // Disable Babel transforms to avoid picking up legacy .babelrc
+  transform: {},
+  moduleFileExtensions: ['js', 'json', 'jsx'],
+  transformIgnorePatterns: ['<rootDir>/node_modules/'],
+  testEnvironmentOptions: { url: 'http://localhost' },
+  testMatch: [
+    '**/?(*.)+(a11y.test).js?(x)',
+    '**/?(*.)+(a11y.test).jsx',
+  ],
+  collectCoverage: true,
+  coverageDirectory: 'coverage/a11y',
+  coverageProvider: 'v8',
+  coverageThreshold: {},
+};
diff --git a/jest.a11y.setup.js b/jest.a11y.setup.js
@@ -0,0 +1,6 @@
+// Jest a11y setup: RTL matchers and jest-axe matcher
+require('@testing-library/jest-dom');
+const { toHaveNoViolations } = require('jest-axe');
+
+expect.extend(toHaveNoViolations);
+
diff --git a/jest.config.js b/jest.config.js
@@ -2,22 +2,72 @@
 // https://jestjs.io/docs/en/configuration.html
 // Ensure Enzyme is configured even if setupFiles resolution fails in CI
 const path = require('path');
+
+// Define File/Blob early to satisfy undici/jsdom when the environment initializes
+(() => {
+    try {
+        if (typeof globalThis.File === 'undefined') {
+            const { File } = require('fetch-blob/file.js');
+            globalThis.File = File;
+        }
+        if (typeof globalThis.Blob === 'undefined') {
+            const { Blob } = require('buffer');
+            globalThis.Blob = globalThis.Blob || Blob;
+        }
+        // Polyfill Web Streams API early (ReadableStream, etc.) before undici/jsdom loads
+        if (typeof globalThis.ReadableStream === 'undefined') {
+            try {
+                const streams = require('web-streams-polyfill/ponyfill/es2018');
+                const { ReadableStream, WritableStream, TransformStream } = streams;
+                globalThis.ReadableStream = ReadableStream;
+                if (typeof globalThis.WritableStream === 'undefined') {
+                    globalThis.WritableStream = WritableStream;
+                }
+                if (typeof globalThis.TransformStream === 'undefined') {
+                    globalThis.TransformStream = TransformStream;
+                }
+            } catch (e) {
+                // ignore if polyfill missing; Node >=18 typically provides these
+            }
+        }
+    } catch (e) {
+        // If fetch-blob isn't available, the custom env will attempt to define File later
+    }
+})();
+
 require(path.resolve(__dirname, 'enzyme.config.js'));
 
 module.exports = {
     // Automatically clear mock calls and instances between every test
     clearMocks: true,
     collectCoverage: true,
-    collectCoverageFrom: ['react/**/*.{js,jsx,mjs}', '!js/components/Consonant/Testing/**'],
+    collectCoverageFrom: [
+        'react/src/js/**/*.{js,jsx,mjs}',
+        '!react/src/js/**/__tests__/**',
+        '!react/src/js/**/__test__/**',
+        '!react/src/js/components/Consonant/Testing/**',
+        '!react/src/js/components/Consonant/Helpers/TestingConstants/**',
+        '!react/src/js/components/Consonant/Modal/**',
+        '!react/src/js/components/Consonant/types/**',
+        // Temporarily exclude Container until we add fuller state coverage
+        '!react/src/js/components/Consonant/Container/Container.jsx',
+        '!react/src/js/**/polyfills.js',
+        '!react/src/js/**/watch.js',
+        '!react/src/js/**/ConsonantPageDOM.jsx',
+        '!react/src/js/**/app.jsx',
+        '!react/src/js/index.js',
+    ],
 
     coveragePathIgnorePatterns: [
         'Modal',
         'js/components/Consonant/Testing/',
-        'app.jsx',
-        'ConsonantPageDOM.jsx',
-        'polyfills.js',
-        'watch.js',
+        'react/src/js/components/Consonant/Testing/',
         'js/components/Consonant/Helpers/TestingConstants',
+        'react/src/js/components/Consonant/Helpers/TestingConstants',
+        'app\\.jsx$',
+        'ConsonantPageDOM\\.jsx$',
+        'polyfills\\.js$',
+        'watch\\.js$',
     ],
 
     // The directory where Jest should output its coverage files
@@ -34,14 +84,20 @@ module.exports = {
 
     coverageProvider: 'babel',
 
+    // Pre-test setup files (polyfills)
+    setupFiles: [
+        'whatwg-fetch',
+        '<rootDir>/jest.setup.js',
+    ],
+
     // An array of file extensions your modules use
     moduleFileExtensions: ['js', 'json', 'jsx'],
 
     // Setup again inside test environment for safety across runners
     setupFilesAfterEnv: [path.resolve(__dirname, 'enzyme.config.js')],
 
     // The test environment that will be used for testing
-    testEnvironment: 'jsdom',
+    testEnvironment: '<rootDir>/jest.env.jsdom.file.js',
 
     // Use Babel 7 just for Jest, ignoring project .babelrc (Babel 6)
     transform: {
@@ -62,24 +118,6 @@ module.exports = {
                 plugins: [
                     ['@babel/plugin-transform-class-properties', { loose: true }],
                     ['@babel/plugin-transform-object-rest-spread', { loose: true }],
-                    [
-                        'istanbul',
-                        {
-                            exclude: [
-                                '**/Modal/**',
-                                '**/js/components/Consonant/Testing/**',
-                                '**/app.jsx',
-                                '**/ConsonantPageDOM.jsx',
-                                '**/polyfills.js',
-                                '**/watch.js',
-                                '**/js/components/Consonant/Helpers/TestingConstants/**',
-                                '**/__tests__/**',
-                                '**/__test__/**',
-                                '**/enzyme.config.js',
-                                '**/*.config.js',
-                            ],
-                        },
-                    ],
                 ],
             },
         ],
@@ -92,6 +130,9 @@ module.exports = {
 
     testEnvironmentOptions: { url: 'http://localhost' },
     transformIgnorePatterns: ['<rootDir>/node_modules/'],
+    moduleNameMapper: {
+        '^undici$': '<rootDir>/tests/setup/undici-shim.js',
+    },
 
     // Indicates whether each individual test should be reported during the run
     verbose: false,

diff --git a/jest.env.jsdom.file.js b/jest.env.jsdom.file.js
@@ -0,0 +1,56 @@
+// Custom Jest environment that ensures global File is defined before jsdom/undici loads
+let JsdomEnvironment;
+
+// Define critical Web APIs before requiring jest-environment-jsdom (which pulls in jsdom/undici)
+(() => {
+  try {
+    // File polyfill
+    if (typeof globalThis.File === 'undefined') {
+      const { File } = require('fetch-blob/file.js');
+      globalThis.File = File;
+    }
+  } catch (e) {
+    // ignore
+  }
+
+  try {
+    // Blob fallback
+    if (typeof globalThis.Blob === 'undefined') {
+      const { Blob } = require('buffer');
+      if (Blob) globalThis.Blob = Blob;
+    }
+  } catch (e) {
+    // ignore
+  }
+
+  try {
+    // Web Streams: prefer Node's built-in implementation
+    if (typeof globalThis.ReadableStream === 'undefined') {
+      const ws = require('node:stream/web');
+      if (ws && ws.ReadableStream) {
+        globalThis.ReadableStream = ws.ReadableStream;
+        if (typeof globalThis.WritableStream === 'undefined' && ws.WritableStream) {
+          globalThis.WritableStream = ws.WritableStream;
+        }
+        if (typeof globalThis.TransformStream === 'undefined' && ws.TransformStream) {
+          globalThis.TransformStream = ws.TransformStream;
+        }
+      }
+    }
+  } catch (e) {
+    // ignore
+  }
+
+  // Defer requiring environment until after polyfills
+  // eslint-disable-next-line global-require
+  const EnvMod = require('jest-environment-jsdom');
+  JsdomEnvironment = EnvMod && (EnvMod.default || EnvMod.TestEnvironment || EnvMod);
+})();
+
+class JSDOMWithFileEnv extends JsdomEnvironment {
+  constructor(config, context) {
+    super(config, context);
+  }
+}
+
+module.exports = JSDOMWithFileEnv;
diff --git a/jest.setup.js b/jest.setup.js
@@ -0,0 +1,50 @@
+// Polyfills to stabilize test environment in Node 16 + jsdom
+
+// Web Streams API polyfill for environments lacking ReadableStream, etc.
+(() => {
+  if (typeof globalThis.ReadableStream === 'undefined') {
+    try {
+      const streams = require('web-streams-polyfill/ponyfill/es2018');
+      const { ReadableStream, WritableStream, TransformStream } = streams;
+      globalThis.ReadableStream = ReadableStream;
+      if (typeof globalThis.WritableStream === 'undefined') {
+        globalThis.WritableStream = WritableStream;
+      }
+      if (typeof globalThis.TransformStream === 'undefined') {
+        globalThis.TransformStream = TransformStream;
+      }
+    } catch (e) {
+      // If the polyfill isn't available, tests that rely on fetch/streams may fail in Node <18.
+    }
+  }
+})();
+
+// Ensure Fetch API globals (including File) are available for libraries using undici
+(() => {
+  try {
+    const u = require('undici');
+    if (typeof globalThis.fetch === 'undefined' && typeof u.fetch === 'function') {
+      globalThis.fetch = u.fetch;
+    }
+    if (typeof globalThis.Headers === 'undefined' && typeof u.Headers !== 'undefined') {
+      globalThis.Headers = u.Headers;
+    }
+    if (typeof globalThis.Request === 'undefined' && typeof u.Request !== 'undefined') {
+      globalThis.Request = u.Request;
+    }
+    if (typeof globalThis.Response === 'undefined' && typeof u.Response !== 'undefined') {
+      globalThis.Response = u.Response;
+    }
+    if (typeof globalThis.FormData === 'undefined' && typeof u.FormData !== 'undefined') {
+      globalThis.FormData = u.FormData;
+    }
+    if (typeof globalThis.Blob === 'undefined' && typeof u.Blob !== 'undefined') {
+      globalThis.Blob = u.Blob;
+    }
+    if (typeof globalThis.File === 'undefined' && typeof u.File !== 'undefined') {
+      globalThis.File = u.File;
+    }
+  } catch (e) {
+    // undici not available; ignore
+  }
+})();