Fix jest tests for ESM

jest.config.js

@@ -1,21 +1,22 @@
-module.exports = {
-    rootDir: './',
-    moduleFileExtensions: ['ts', 'js'],
-    testMatch: ['**/test/**/*.test.ts', '**/test/tests.ts'],
-    coverageProvider: 'v8',
-    coveragePathIgnorePatterns: [
-      '/node_modules/',
-      './jest.config.js',
-      './test',
+/** @type {import('ts-jest').JestConfigWithTsJest} */
+export default {
+  rootDir: "./",
+  moduleFileExtensions: ["ts", "js"],
+  testMatch: ["**/test/**/*.test.ts", "**/test/tests.ts"],
+  coverageProvider: "v8",
+  coveragePathIgnorePatterns: ["/node_modules/", "./jest.config.js", "./test"],
+  extensionsToTreatAsEsm: ['.ts'],
+  reporters: [
+    "default",
+    ["jest-junit", { outputDirectory: "test-results/jest" }],
+  ],
+  coverageReporters: ["lcov", "text", "text-summary"],
+  setupFiles: [],
+  preset: 'ts-jest/presets/default-esm',
+  transform: {
+    "^.+\\.ts?$": [
+      "ts-jest",
+      { useESM: true, tsconfig: "./tsconfig.test.json" },
     ],
-    reporters: [
-      'default',
-      ['jest-junit', { outputDirectory: 'test-results/jest' }]
-    ],
-    coverageReporters: ['lcov', 'text', 'text-summary'],
-    setupFiles: [],
-    preset: 'ts-jest',
-    transform: {
-      '^.+\\.ts?$': ['ts-jest', {tsconfig: './tsconfig.test.json'}]
-    },
-  };
+  },
+};

package.json

@@ -20,8 +20,8 @@
         "build": "rimraf dist && rollup -m -c --environment NODE_ENV:production",
         "postbuild": "echo '{\"type\": \"commonjs\"}'> dist/cjs/package.json",
         "test": "npm run test:node && npm run test:browser",
-        "test:node": "jest --coverage",
-        "test:browser": "jest --coverage --testEnvironment=jsdom"
+        "test:node": "NODE_OPTIONS='--experimental-vm-modules --no-warnings' jest --coverage",
+        "test:browser": "NODE_OPTIONS='--experimental-vm-modules --no-warnings' jest --coverage --testEnvironment=jsdom"
     },
     "author": "Jose F. Romaniello <jfromaniello@gmail.com> (http://joseoncode.com)",
     "contributors": [