Refactor and simplify umd wrapper (#2594)

* Refactor UMD output to check for and use `self` before using `this`,
remove unnecessary parentheses in UMD and IIFE

* Do not render special CJS intro if IIFE and CJS result are identical,
do not render global if not used in intro

src/finalisers/iife.ts

@@ -54,7 +54,7 @@ export default function iife(
 	}
 
 	if (extend) {
-		deps.unshift(`(${thisProp(name)}${_}=${_}${thisProp(name)}${_}||${_}{})`);
+		deps.unshift(`${thisProp(name)}${_}=${_}${thisProp(name)}${_}||${_}{}`);
 		args.unshift('exports');
 	} else if (namedExportsMode && hasExports) {
 		deps.unshift('{}');

src/finalisers/umd.ts

@@ -39,8 +39,6 @@ export default function umd(
 	const _ = options.compact ? '' : ' ';
 	const n = options.compact ? '' : '\n';
 
-	const wrapperOutro = n + n + '})));';
-
 	if (hasExports && !options.name) {
 		error({
 			code: 'INVALID_OPTION',
@@ -53,20 +51,20 @@ export default function umd(
 	const amdDeps = dependencies.map(m => `'${m.id}'`);
 	const cjsDeps = dependencies.map(m => `require('${m.id}')`);
 
-	const trimmed = trimEmptyImports(dependencies);
-	const globalDeps = trimmed.map(module => globalProp(module.globalName));
-	const args = trimmed.map(m => m.name);
+	const trimmedImports = trimEmptyImports(dependencies);
+	const globalDeps = trimmedImports.map(module => globalProp(module.globalName));
+	const factoryArgs = trimmedImports.map(m => m.name);
 
-	if (namedExportsMode && hasExports) {
+	if (namedExportsMode && (hasExports || options.noConflict === true)) {
 		amdDeps.unshift(`'exports'`);
 		cjsDeps.unshift(`exports`);
 		globalDeps.unshift(
-			`(${setupNamespace(options.name, 'global', true, options.globals, options.compact)}${_}=${_}${
+			`${setupNamespace(options.name, 'global', true, options.globals, options.compact)}${_}=${_}${
 				options.extend ? `${globalProp(options.name)}${_}||${_}` : ''
-			}{})`
+			}{}`
 		);
 
-		args.unshift('exports');
+		factoryArgs.unshift('exports');
 	}
 
 	const amdOptions = options.amd || {};
@@ -94,28 +92,42 @@ export default function umd(
 			factory = `var exports${_}=${_}factory(${globalDeps});`;
 		} else if (namedExportsMode) {
 			const module = globalDeps.shift();
-			factory = `var exports${_}=${_}${module};${n}`;
-			factory += `${t}${t}factory(${['exports'].concat(globalDeps)});`;
+			factory =
+				`var exports${_}=${_}${module};${n}` +
+				`${t}${t}factory(${['exports'].concat(globalDeps)});`;
 		}
-		globalExport = `(function()${_}{${n}`;
-		globalExport += `${t}${t}var current${_}=${_}${safeAccess(options.name, options.compact)};${n}`;
-		globalExport += `${t}${t}${factory}${n}`;
-		globalExport += `${t}${t}${globalProp(options.name)}${_}=${_}exports;${n}`;
-		globalExport += `${t}${t}exports.noConflict${_}=${_}function()${_}{${_}`;
-		globalExport += `${globalProp(options.name)}${_}=${_}current;${_}return exports${
-			options.compact ? '' : '; '
-		}};${n}`;
-		globalExport += `${t}})()`;
+		globalExport =
+			`(function()${_}{${n}` +
+			`${t}${t}var current${_}=${_}${safeAccess(options.name, options.compact)};${n}` +
+			`${t}${t}${factory}${n}` +
+			`${t}${t}${globalProp(options.name)}${_}=${_}exports;${n}` +
+			`${t}${t}exports.noConflict${_}=${_}function()${_}{${_}` +
+			`${globalProp(options.name)}${_}=${_}current;${_}return exports${
+				options.compact ? '' : '; '
+			}};${n}` +
+			`${t}})()`;
 	} else {
-		globalExport = `(${defaultExport}factory(${globalDeps}))`;
+		globalExport = `${defaultExport}factory(${globalDeps})`;
 	}
 
-	let wrapperIntro = `(function${_}(global,${_}factory)${_}{${n}`;
-	wrapperIntro += `${t}typeof exports${_}===${_}'object'${_}&&${_}typeof module${_}!==${_}'undefined'${_}?`;
-	wrapperIntro += `${_}${cjsExport}factory(${cjsDeps.join(`,${_}`)})${_}:${n}`;
-	wrapperIntro += `${t}typeof ${define}${_}===${_}'function'${_}&&${_}${define}.amd${_}?${_}${define}(${amdParams}factory)${_}:${n}`;
-	wrapperIntro += `${t}${globalExport};${n}`;
-	wrapperIntro += `}(this,${_}(function${_}(${args})${_}{${useStrict}${n}`;
+	const iifeNeedsGlobal = hasExports || (options.noConflict === true && namedExportsMode);
+	const globalParam = iifeNeedsGlobal ? `global,${_}` : '';
+	const globalArg = iifeNeedsGlobal
+		? `typeof self${_}!==${_}'undefined'${_}?${_}self${_}:${_}this,${_}`
+		: '';
+	const cjsIntro = iifeNeedsGlobal
+		? `${t}typeof exports${_}===${_}'object'${_}&&${_}typeof module${_}!==${_}'undefined'${_}?` +
+		  `${_}${cjsExport}factory(${cjsDeps.join(`,${_}`)})${_}:${n}`
+		: '';
+
+	const wrapperIntro =
+		`(function${_}(${globalParam}factory)${_}{${n}` +
+		cjsIntro +
+		`${t}typeof ${define}${_}===${_}'function'${_}&&${_}${define}.amd${_}?${_}${define}(${amdParams}factory)${_}:${n}` +
+		`${t}${globalExport};${n}` +
+		`}(${globalArg}function${_}(${factoryArgs})${_}{${useStrict}${n}`;
+
+	const wrapperOutro = n + n + '}));';
 
 	// var foo__default = 'default' in foo ? foo['default'] : foo;
 	const interopBlock = getInteropBlock(dependencies, options, graph.varOrConst);

test/cli/samples/indent-none/_expected.js

@@ -1,9 +1,8 @@
-(function (global, factory) {
-typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+(function (factory) {
 typeof define === 'function' && define.amd ? define(factory) :
-(factory());
-}(this, (function () { 'use strict';
+factory();
+}(function () { 'use strict';
 
 assert.equal( 1 + 1, 2 );
 
-})));
+}));

test/cli/samples/module-name/_expected.js

@@ -1,11 +1,11 @@
 (function (global, factory) {
 	typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
 	typeof define === 'function' && define.amd ? define(factory) :
-	(global.myBundle = factory());
-}(this, (function () { 'use strict';
+	global.myBundle = factory();
+}(typeof self !== 'undefined' ? self : this, function () { 'use strict';
 
 	var main = 42;
 
 	return main;
 
-})));
+}));

test/cli/samples/no-conflict/_expected.js

@@ -7,10 +7,10 @@
 		global.conflictyName = exports;
 		exports.noConflict = function() { global.conflictyName = current; return exports; };
 	})();
-}(this, (function () { 'use strict';
+}(typeof self !== 'undefined' ? self : this, function () { 'use strict';
 
 	var main = {};
 
 	return main;
 
-})));
+}));

test/form/samples/absolute-path-resolver/_expected/iife.js

@@ -8,4 +8,4 @@
     a();
     a();
 
-}());
+}());

test/form/samples/absolute-path-resolver/_expected/umd.js

@@ -1,8 +1,7 @@
-(function (global, factory) {
-    typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+(function (factory) {
     typeof define === 'function' && define.amd ? define(factory) :
-    (factory());
-}(this, (function () { 'use strict';
+    factory();
+}(function () { 'use strict';
 
     var a = () => {
         console.log('props');
@@ -11,4 +10,4 @@
     a();
     a();
 
-})));
+}));

test/form/samples/arrow-function-call-parameters/_expected/umd.js

@@ -1,8 +1,7 @@
-(function (global, factory) {
-	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+(function (factory) {
 	typeof define === 'function' && define.amd ? define(factory) :
-	(factory());
-}(this, (function () { 'use strict';
+	factory();
+}(function () { 'use strict';
 
 	const callArg = arg => arg();
 	callArg( () => console.log( 'effect' ) );
@@ -34,4 +33,4 @@
 	const multiArgument2 = ( func, obj ) => func( obj );
 	multiArgument2( obj => obj.foo.bar = 1, {} );
 
-})));
+}));

test/form/samples/arrow-function-return-values/_expected/umd.js

@@ -1,8 +1,7 @@
-(function (global, factory) {
-	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+(function (factory) {
 	typeof define === 'function' && define.amd ? define(factory) :
-	(factory());
-}(this, (function () { 'use strict';
+	factory();
+}(function () { 'use strict';
 
 	(() => () => console.log( 'effect' ))()();
 	(() => () => () => console.log( 'effect' ))()()();
@@ -15,4 +14,4 @@
 	(() => ({ foo: () => console.log( 'effect' ) }))().foo();
 	(() => ({ foo: () => ({ bar: () => console.log( 'effect' ) }) }))().foo().bar();
 
-})));
+}));

test/form/samples/assignment-to-array-buffer-view/_expected/umd.js

@@ -1,8 +1,8 @@
 (function (global, factory) {
 	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
 	typeof define === 'function' && define.amd ? define(['exports'], factory) :
-	(factory((global.bundle = {})));
-}(this, (function (exports) { 'use strict';
+	factory(global.bundle = {});
+}(typeof self !== 'undefined' ? self : this, function (exports) { 'use strict';
 
 	var buffer = new ArrayBuffer( 8 );
 
@@ -15,4 +15,4 @@
 
 	Object.defineProperty(exports, '__esModule', { value: true });
 
-})));
+}));

test/form/samples/assignment-to-exports-class-declaration/_expected/umd.js

@@ -1,12 +1,12 @@
 (function (global, factory) {
 	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
 	typeof define === 'function' && define.amd ? define(['exports'], factory) :
-	(factory((global.myModule = {})));
-}(this, (function (exports) { 'use strict';
+	factory(global.myModule = {});
+}(typeof self !== 'undefined' ? self : this, function (exports) { 'use strict';
 
 	exports.Foo = class Foo {};
 	exports.Foo = lol( exports.Foo );
 
 	Object.defineProperty(exports, '__esModule', { value: true });
 
-})));
+}));

test/form/samples/assignment-to-exports/_expected/umd.js

@@ -1,8 +1,8 @@
 (function (global, factory) {
 	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
 	typeof define === 'function' && define.amd ? define(['exports'], factory) :
-	(factory((global.bundle = {})));
-}(this, (function (exports) { 'use strict';
+	factory(global.bundle = {});
+}(typeof self !== 'undefined' ? self : this, function (exports) { 'use strict';
 
 	// Unassigned export
 	var foo1;
@@ -32,4 +32,4 @@
 
 	Object.defineProperty(exports, '__esModule', { value: true });
 
-})));
+}));

test/form/samples/assignment-to-global/_expected/umd.js

@@ -1,9 +1,8 @@
-(function (global, factory) {
-	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+(function (factory) {
 	typeof define === 'function' && define.amd ? define(factory) :
-	(factory());
-}(this, (function () { 'use strict';
+	factory();
+}(function () { 'use strict';
 
 	globalVar = 1;
 
-})));
+}));

test/form/samples/async-function-unused/_expected/umd.js

@@ -1,13 +1,12 @@
-(function (global, factory) {
-	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+(function (factory) {
 	typeof define === 'function' && define.amd ? define(factory) :
-	(factory());
-}(this, (function () { 'use strict';
+	factory();
+}(function () { 'use strict';
 
 	async function foo () {
 		return 'foo';
 	}
 
 	foo().then( value => console.log( value ) );
 
-})));
+}));

test/form/samples/banner-and-footer/_expected/umd.js

@@ -2,15 +2,14 @@
 /* first banner */
 /* second banner */
 /* 3rd banner */
-(function (global, factory) {
-	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+(function (factory) {
 	typeof define === 'function' && define.amd ? define(factory) :
-	(factory());
-}(this, (function () { 'use strict';
+	factory();
+}(function () { 'use strict';
 
 	console.log( 'hello world' );
 
-})));
+}));
 /* this is a footer */
 /* first footer */
 /* second footer */

test/form/samples/block-comments/_expected/umd.js

@@ -1,8 +1,7 @@
-(function (global, factory) {
-	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+(function (factory) {
 	typeof define === 'function' && define.amd ? define(factory) :
-	(factory());
-}(this, (function () { 'use strict';
+	factory();
+}(function () { 'use strict';
 
 	function foo () {
 		return embiggen( 6, 7 );
@@ -20,4 +19,4 @@
 
 	alert( foo() );
 
-})));
+}));

test/form/samples/body-less-for-loops/_expected/iife.js

@@ -14,4 +14,4 @@
 	let index;
 	for ( index in array ) console.log( index );
 
-}());
+}());

test/form/samples/body-less-for-loops/_expected/umd.js

@@ -1,8 +1,7 @@
-(function (global, factory) {
-	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+(function (factory) {
 	typeof define === 'function' && define.amd ? define(factory) :
-	(factory());
-}(this, (function () { 'use strict';
+	factory();
+}(function () { 'use strict';
 
 	for ( let i = 0; i < 10; i += 1 ) console.log( i );
 	for ( const letter of array ) console.log( letter );
@@ -17,4 +16,4 @@
 	let index;
 	for ( index in array ) console.log( index );
 
-})));
+}));

test/form/samples/catch-parameter-shadowing/_expected/umd.js

@@ -1,8 +1,8 @@
 (function (global, factory) {
 	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
 	typeof define === 'function' && define.amd ? define(['exports'], factory) :
-	(factory((global.bundle = {})));
-}(this, (function (exports) { 'use strict';
+	factory(global.bundle = {});
+}(typeof self !== 'undefined' ? self : this, function (exports) { 'use strict';
 
 	const e = 2.7182818284;
 
@@ -18,4 +18,4 @@
 
 	Object.defineProperty(exports, '__esModule', { value: true });
 
-})));
+}));

test/form/samples/circular-member-expression/_expected/umd.js

@@ -1,13 +1,12 @@
-(function (global, factory) {
-  typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+(function (factory) {
   typeof define === 'function' && define.amd ? define(factory) :
-  (factory());
-}(this, (function () { 'use strict';
+  factory();
+}(function () { 'use strict';
 
   var foo = function() {
     foo.toString = null;
   }.toString();
 
   console.log(foo);
 
-})));
+}));