'new' plugin

README.md

@@ -92,6 +92,7 @@ Plugins are registered by calling `jsep.plugins.register()` with the plugin(s) a
 #### JSEP-provided plugins:
 * `jsepTernary`: Built-in by default, adds support for ternary `a ? b : c` expressions
 * `jsepComment`: Adds support for ignoring comments: `a /* ignore this */ > 1 // ignore this too`
+* `jsepNew`: Adds 'new' keyword support: `new Date()`
 * `jsepObject`: Adds object expression support: `{ a: 1, b: { c }}`
 
 #### How to add plugins:

rollup.config.js

@@ -69,6 +69,7 @@ export default [
 	},
 	...[
 		'jsepComment',
+		'jsepNew',
 		'jsepObject',
 	].map(name => ({
 		input: `src/plugins/${name}.js`,

src/plugins/jsepNew.js

@@ -0,0 +1,18 @@
+export default {
+	name: 'jsepNew',
+
+	init(jsep) {
+		jsep.addUnaryOp('new');
+
+		jsep.hooks.add('after-token', function gobbleNew(env) {
+			const node = env.node;
+			if (node && node.operator === 'new') {
+				if (!node.argument || ![jsep.CALL_EXP, jsep.MEMBER_EXP].includes(node.argument.type)) {
+					this.throwError('Expected new function()');
+				}
+				env.node = node.argument;
+				env.node.type = 'NewExpression';
+			}
+		});
+	}
+};

test/plugins/jsepNew.test.js

@@ -0,0 +1,55 @@
+import jsep from '../../src/index.js';
+import jsepNew from '../../src/plugins/jsepNew.js';
+import { testParser, resetJsepHooks } from '../test_utils.js';
+
+const { test } = QUnit;
+
+(function () {
+	QUnit.module('Plugin:New', (qunit) => {
+		qunit.before(() => jsep.plugins.register(jsepNew));
+		qunit.after(() => {
+			jsep.removeUnaryOp('new');
+			resetJsepHooks();
+		});
+
+		test('should parse basic "new" expression', (assert) => {
+			testParser('new Date(123)', {
+				type: "NewExpression",
+				arguments: [
+					{
+						type: "Literal",
+						value: 123,
+						raw: "123"
+					}
+				],
+				callee: {
+					type: "Identifier",
+					name: "Date"
+				}
+			}, assert);
+		});
+
+		[
+			'new A().b',
+			'new A() != null',
+			'new A(), new B()',
+			'[new A(), new A()]',
+			'new A("1")',
+			'new A(1, 2)',
+		].forEach(expr => test(`should not throw any errors for ${expr}`, (assert) => {
+			testParser(expr, {}, assert);
+		}));
+
+		[
+			'new A',
+			'new A,new B',
+			'fn(new A)',
+			'!new A',
+			'new 123',
+			'new (a > 2 ? A : B)',
+			'new (a > 1)',
+		].forEach(expr => test(`should give an error for invalid expression ${expr}`, (assert) => {
+			assert.throws(() => jsep(expr));
+		}));
+	});
+}());

test/tests.js

@@ -4,4 +4,5 @@ export * from './hooks.test.js';
 export * from './plugins.test.js';
 export * from './plugins/jsepTernary.test.js';
 export * from './plugins/jsepComment.test.js';
+export * from './plugins/jsepNew.test.js';
 export * from './plugins/jsepObject.test.js';