Ensure system-reserved identifiers are deduped

src/Chunk.ts

@@ -1088,16 +1088,17 @@ export default class Chunk {
 		if (this.needsExportsShim) {
 			usedNames.add(MISSING_EXPORT_SHIM_VARIABLE);
 		}
-		if (options.format !== 'es') {
-			usedNames.add('exports');
-			if (options.format === 'cjs') {
-				usedNames
-					.add(INTEROP_DEFAULT_VARIABLE)
-					.add('require')
-					.add('module')
-					.add('__filename')
-					.add('__dirname');
-			}
+		switch (options.format) {
+			case 'es':
+				break;
+			case 'cjs':
+				usedNames.add(INTEROP_DEFAULT_VARIABLE).add('require').add('__filename').add('__dirname');
+			// fallthrough
+			case 'system':
+				usedNames.add('module');
+			// fallthrough
+			default:
+				usedNames.add('exports');
 		}
 
 		deconflictChunk(

test/form/samples/protect-cjs-globals/_expected/system.js

@@ -5,7 +5,7 @@ System.register('bundle', [], function (exports) {
 
 			const exports$1 = exports('exports', 1);
 			const require = exports('require', 2);
-			const module = exports('module', 3);
+			const module$1 = exports('module', 3);
 			const __filename = exports('__filename', 4);
 			const __dirname = exports('__dirname', 5);
 

test/form/samples/sequence-expression/_expected/system.js

@@ -23,9 +23,9 @@ System.register([], function () {
             var g = ((() => {console.log(foo$1());})(), 1);
 
             // should maintain this context
-            var module = {};
-            module.bar = function () { console.log( 'bar' );};
-            var h = (0, module.bar)();
+            var module$1 = {};
+            module$1.bar = function () { console.log( 'bar' );};
+            var h = (0, module$1.bar)();
 
         }
     };

test/form/samples/system-module-reserved/_config.js

@@ -0,0 +1,10 @@
+module.exports = {
+	description: 'does not output reserved system format identifiers',
+	options: {
+		external: ['test'],
+		output: {
+			name: 'systemReserved',
+			globals: { test: 'test' }
+		}
+	}
+};

test/form/samples/system-module-reserved/_expected/amd.js

@@ -0,0 +1,5 @@
+define(['test'], function (test) { 'use strict';
+
+	console.log(test.module, test.other);
+
+});

test/form/samples/system-module-reserved/_expected/cjs.js

@@ -0,0 +1,5 @@
+'use strict';
+
+var test = require('test');
+
+console.log(test.module, test.other);

test/form/samples/system-module-reserved/_expected/es.js

@@ -0,0 +1,3 @@
+import { module, other } from 'test';
+
+console.log(module, other);

test/form/samples/system-module-reserved/_expected/iife.js

@@ -0,0 +1,6 @@
+(function (test) {
+	'use strict';
+
+	console.log(test.module, test.other);
+
+}(test));

test/form/samples/system-module-reserved/_expected/system.js

@@ -0,0 +1,15 @@
+System.register('systemReserved', ['test'], function () {
+	'use strict';
+	var module$1, other;
+	return {
+		setters: [function (module) {
+			module$1 = module.module;
+			other = module.other;
+		}],
+		execute: function () {
+
+			console.log(module$1, other);
+
+		}
+	};
+});

test/form/samples/system-module-reserved/_expected/umd.js

@@ -0,0 +1,9 @@
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory(require('test')) :
+	typeof define === 'function' && define.amd ? define(['test'], factory) :
+	(global = global || self, factory(global.test));
+}(this, (function (test) { 'use strict';
+
+	console.log(test.module, test.other);
+
+})));

test/form/samples/system-module-reserved/main.js

@@ -0,0 +1,3 @@
+import { module, other } from 'test';
+
+console.log(module, other);