Turns out testing with JSDom is first-class in Jest!

Author: bennothommo

.babelrc.json

@@ -23,7 +23,7 @@
     },
     "ignorePatterns": [
         "rollup.config.mjs",
-        "tests/jest.config.js",
+        "jest.config.js",
         "dist/"
     ],
     "overrides": [

.eslintrc.json

@@ -1,3 +1,3 @@
 dist/
 node_modules
-tests/coverage/*
+coverage

.gitignore

@@ -0,0 +1,15 @@
+module.exports = {
+    presets: [
+        [
+            '@babel/preset-env',
+            {
+                targets: {
+                    node: 'current',
+                },
+            },
+        ],
+    ],
+    plugins: [
+        '@babel/plugin-transform-runtime',
+    ],
+};

babel.config.js

@@ -1,34 +1,36 @@
-/*
+/**
  * For a detailed explanation regarding each configuration property, visit:
  * https://jestjs.io/docs/configuration
  */
 
-module.exports = {
+/** @type {import('jest').Config} */
+const config = {
     // All imported modules in your tests should be mocked automatically
     // automock: false,
 
     // Stop running tests after `n` failures
     // bail: 0,
 
     // The directory where Jest should store its cached dependency information
-    // cacheDirectory: "/private/var/folders/81/m6w95r0j7ms_10c47hdbz4gw0000gn/T/jest_dx",
+    // cacheDirectory: "/tmp/jest_rs",
 
-    // Automatically clear mock calls, instances and results before every test
+    // Automatically clear mock calls, instances, contexts and results before every test
     clearMocks: true,
 
     // Indicates whether the coverage information should be collected while executing the test
-    // collectCoverage: false,
+    collectCoverage: true,
 
     // An array of glob patterns indicating a set of files for which coverage information should be collected
     // collectCoverageFrom: undefined,
 
     // The directory where Jest should output its coverage files
-    // coverageDirectory: undefined,
+    coverageDirectory: "coverage",
 
     // An array of regexp pattern strings used to skip coverage collection
-    // coveragePathIgnorePatterns: [
-    //   "/node_modules/"
-    // ],
+    coveragePathIgnorePatterns: [
+      "/node_modules/",
+      "/tests/fixtures/",
+    ],
 
     // Indicates which provider should be used to instrument code for coverage
     // coverageProvider: "babel",
@@ -50,6 +52,11 @@ module.exports = {
     // Make calling deprecated APIs throw helpful error messages
     // errorOnDeprecated: false,
 
+    // The default configuration for fake timers
+    // fakeTimers: {
+    //   "enableGlobally": false
+    // },
+
     // Force coverage collection from ignored files using an array of glob patterns
     // forceCoverageMatch: [],
 
@@ -73,6 +80,8 @@ module.exports = {
     // An array of file extensions your modules use
     // moduleFileExtensions: [
     //   "js",
+    //   "mjs",
+    //   "cjs",
     //   "jsx",
     //   "ts",
     //   "tsx",
@@ -137,7 +146,7 @@ module.exports = {
     // snapshotSerializers: [],
 
     // The test environment that will be used for testing
-    // testEnvironment: "jest-environment-node",
+    testEnvironment: "jsdom",
 
     // Options that will be passed to the testEnvironment
     // testEnvironmentOptions: {},
@@ -165,14 +174,10 @@ module.exports = {
     // This option allows use of a custom test runner
     // testRunner: "jest-circus/runner",
 
-    // This option sets the URL for the jsdom environment. It is reflected in properties such as location.href
-    // testURL: "http://localhost",
-
-    // Setting this value to "fake" allows the use of fake timers for functions such as "setTimeout"
-    // timers: "real",
-
     // A map from regular expressions to paths to transformers
-    // transform: undefined,
+    transform: {
+        "^.+\\.jsx?$": "babel-jest",
+    },
 
     // An array of regexp pattern strings that are matched against all source file paths, matched files will skip transformation
     // transformIgnorePatterns: [
@@ -192,3 +197,5 @@ module.exports = {
     // Whether to use watchman for file crawling
     // watchman: true,
 };
+
+module.exports = config;