feat(jest): create jest config package for unit testing (#3678)

* feat(jest): create jest config package for unit testing
* chore: housekeeping
* fix: now we need to explicitly allow importing without extension
* fix: recover EditorDriverInterface import
* Apply suggestions from code review
* chore: yarn

Signed-off-by: Sami Mazouz <sychocouldy@gmail.com>

js-packages/jest-config/index.cjs

@@ -0,0 +1,22 @@
+const path = require('path');
+
+module.exports = (options = {}) => ({
+  testEnvironment: 'jsdom',
+  extensionsToTreatAsEsm: ['.ts', '.tsx'],
+  transform: {
+    '^.+\\.[tj]sx?$': [
+      'babel-jest',
+      require('flarum-webpack-config/babel.config.js'),
+    ],
+    '^.+\\.tsx?$': [
+      'ts-jest',
+      {
+        useESM: true,
+      },
+    ],
+  },
+  preset: 'ts-jest',
+  setupFilesAfterEnv: [path.resolve(__dirname, 'setup-env.js')],
+  moduleDirectories: ['node_modules', 'src'],
+  ...options,
+});