ESM exports [feat]

.babelrc.js

@@ -0,0 +1,22 @@
+/* --------------------
+ * is-it-type module
+ * Babel config
+ * ------------------*/
+
+'use strict';
+
+// Exports
+
+module.exports = api => ({
+	presets: [
+		[
+			'@babel/preset-env',
+			{
+				// Loose mode to reduce ponyfills
+				loose: true,
+				// If running tests, compile for current Node version
+				...(api.env('test') && {targets: {node: 'current'}})
+			}
+		]
+	]
+});

.eslintignore

@@ -1,2 +1,3 @@
 !.*
+dist
 coverage

.eslintrc.js

@@ -11,5 +11,15 @@ module.exports = {
 	extends: [
 		'@overlookmotel/eslint-config',
 		'@overlookmotel/eslint-config-node'
+	],
+	overrides: [
+		{
+			// Entry point references files in dist folder which only exist after build
+			files: ['./index.js'],
+			rules: {
+				'node/no-missing-require': 'off',
+				'import/no-unresolved': 'off'
+			}
+		}
 	]
 };

.gitignore

@@ -1,3 +1,4 @@
 .DS_Store
 coverage
+dist
 node_modules

.npmignore

@@ -1,10 +1,13 @@
+src
 test
 coverage
 
 .DS_Store
+.babelrc.js
 .editorconfig
 .eslintignore
 .eslintrc.js
 .gitattributes
 .travis.yml
 jest.config.js
+rollup.config.js

README.md

@@ -7,7 +7,7 @@
 
 # Determine type of a variable
 
-All the functions from [core-util-is](https://www.npmjs.com/package/core-util-is) plus a few extras.
+All the functions from [core-util-is](https://www.npmjs.com/package/core-util-is) plus a few extras, in both CJS and ES forms for use in Node.js or browser.
 
 ## Usage
 
@@ -17,6 +17,12 @@ All the functions from [core-util-is](https://www.npmjs.com/package/core-util-is
 const { isString } = require('is-it-type');
 ```
 
+or:
+
+```js
+import { isString } from 'is-it-type/es';
+```
+
 ### Use a method
 
 ```js

es/.eslintrc.js

@@ -0,0 +1,23 @@
+/* --------------------
+ * is-it-type module
+ * ESLint src config
+ * ------------------*/
+
+'use strict';
+
+// Exports
+
+module.exports = {
+	overrides: [{
+		files: ['!.*'],
+		parserOptions: {
+			sourceType: 'module'
+		},
+		rules: {
+			'node/no-unsupported-features/es-syntax': ['error', {ignores: ['modules']}],
+			// Entry point references files in dist folder which only exist after build
+			'node/no-missing-import': 'off',
+			'import/no-unresolved': 'off'
+		}
+	}]
+};

es/index.js

@@ -0,0 +1,8 @@
+/* --------------------
+ * is-it-type module
+ * ESM Entry point
+ * ------------------*/
+
+// Exports
+
+export * from '../dist/esm/is-it-type.js';

index.js

@@ -1,9 +1,10 @@
 /* --------------------
  * is-it-type module
+ * CJS Entry point
  * ------------------*/
 
 'use strict';
 
 // Exports
 
-module.exports = require('./lib/index.js');
+module.exports = require('./dist/cjs/is-it-type.js');

jest.config.js

@@ -10,13 +10,24 @@
 module.exports = {
 	testEnvironment: 'node',
 	coverageDirectory: 'coverage',
-	collectCoverageFrom: [
-		'**/*.js',
-		'!.**',
-		'!**/.**',
-		'!**/node_modules/**',
-		'!test/**',
-		'!jest.config.js'
-	],
-	setupFilesAfterEnv: ['jest-extended']
+	collectCoverageFrom: ['src/**/*.js'],
+	setupFilesAfterEnv: ['jest-extended'],
+	// Resolve `import from 'is-it-type'` to src or build, depending on env variable
+	moduleNameMapper: {
+		'^is-it-type$': resolvePath()
+	}
 };
+
+function resolvePath() {
+	const testEnv = (process.env.TEST_ENV || '').toLowerCase(),
+		isProd = process.env.NODE_ENV === 'production';
+
+	if (!testEnv) return '<rootDir>/src/index.js';
+	if (testEnv === 'cjs') return '<rootDir>/index.js';
+	if (testEnv === 'esm') return `<rootDir>/dist/esm/is-it-type${isProd ? '.min' : ''}.js`;
+	if (testEnv === 'umd') return `<rootDir>/dist/umd/is-it-type${isProd ? '.min' : ''}.js`;
+
+	throw new Error(
+		`Invalid TEST_ENV '${testEnv}' - valid options are 'cjs', 'esm', 'umd' or undefined`
+	);
+}