Convert package to ES Module

jest.config.js → jest.config.cjs

@@ -1,11 +1,13 @@
 /** @type {import('ts-jest/dist/types').InitialOptionsTsJest} */
 module.exports = {
+    extensionsToTreatAsEsm: ['.ts'],
     preset: 'ts-jest',
     testEnvironment: 'node',
     collectCoverage: true,
     globals: {
         'ts-jest': {
             tsconfig: 'tsconfig.test.json',
+            useESM: true,
         },
     },
 };

package.json

@@ -2,12 +2,10 @@
   "name": "@prezly/theme-kit-nextjs",
   "version": "1.18.2",
   "description": "Data layer and utility library for developing Prezly themes with NextJS",
+  "type": "module",
   "main": "build/index.js",
   "types": "build/index.d.ts",
-  "files": [
-    "build",
-    "src"
-  ],
+  "files": ["build"],
   "engines": {
     "node": ">= 14.x",
     "npm": ">= 7.x"
@@ -31,7 +29,7 @@
     "clean": "rimraf build/ node_modules/",
     "build": "tsc --project .",
     "watch": "tsc --watch --preserveWatchOutput --project .",
-    "test": "jest",
+    "test": "node --experimental-vm-modules node_modules/jest/bin/jest.js",
     "typecheck": "tsc --noEmit --incremental --project .",
     "lint": "eslint src",
     "lint:fix": "npm run lint -- --fix",

src/intl/index.ts

@@ -1,4 +1,4 @@
 export * from './languages';
 export * from './locale';
-export { default as localeConfig } from './localeConfig';
+export { localeConfig } from './localeConfig';
 export * from './localeObject';

src/intl/locale.test.ts

@@ -1,3 +1,5 @@
+import { jest } from '@jest/globals';
+
 import {
     DEFAULT_LOCALE,
     DUMMY_DEFAULT_LOCALE,

src/intl/localeConfig.js → src/intl/localeConfig.ts

@@ -3,9 +3,9 @@
  * Together with permutation performed lower in the code,
  * the exported list represents all of the possible locale codes that Next.js theme application might accept.
  */
-const supportedLocales = require('./localeList');
+import { localeList } from './localeList';
 
-const lowercaseLocales = supportedLocales.map((l) => l.toLowerCase());
+const lowercaseLocales = localeList.map((l) => l.toLowerCase());
 
 // Get all permutations for the shorter locale codes supported by Prezly (e.g. short region codes and neutral language codes)
 const lowercaseLocalPermutations = Array.from(
@@ -20,4 +20,4 @@ const lowercaseLocalPermutations = Array.from(
     ]),
 ).sort();
 
-module.exports = lowercaseLocalPermutations;
+export const localeConfig = lowercaseLocalPermutations;

src/intl/localeList.js → src/intl/localeList.ts

@@ -1,7 +1,7 @@
 /**
  * This list is pulled from the main Prezly application. The underscores are replaced with dashes.
  */
-module.exports = [
+export const localeList = [
     'af-ZA',
     'ar',
     'ar-AE',

src/intl/localeObject.ts

@@ -1,4 +1,4 @@
-import localeConfig from './localeConfig';
+import { localeConfig } from './localeConfig';
 
 /**
  * This class is created to simplify working with locales and transforming between different locale code formats.

tsconfig.json

@@ -1,13 +1,13 @@
 {
   "compilerOptions": {
-    "allowJs": true,
+    "allowJs": false,
     "allowSyntheticDefaultImports": true,
     "declaration": true,
     "downlevelIteration": true,
     "esModuleInterop": true,
     "forceConsistentCasingInFileNames": true,
     "lib": ["dom", "es2019"],
-    "module": "commonjs",
+    "module": "esnext",
     "moduleResolution": "node",
     "noImplicitAny": true,
     "noImplicitReturns": true,

tsconfig.test.json

@@ -1,5 +1,5 @@
 {
   "extends": "./tsconfig.json",
   "exclude": ["node_modules"],
-  "include": ["./src", "next-env.d.ts", "jest.config.js"]
+  "include": ["./src", "next-env.d.ts", "jest.config.cjs"]
 }