Use more efficient loops for const bindings

rollup · Sep 16, 2021 · e819692 · e819692
1 parent b7a3933
commit e819692
Show file tree

Hide file tree

Showing 14 changed files with 28 additions and 23 deletions.
diff --git a/src/finalisers/shared/getExportBlock.ts b/src/finalisers/shared/getExportBlock.ts
@@ -14,12 +14,13 @@ export function getExportBlock(
 	interop: GetInterop,
 	{
 		_,
-		s,
+		cnst,
 		directReturnFunctionRight,
 		getDirectReturnFunctionLeft,
 		getFunctionIntro,
 		getPropertyAccess,
-		n
+		n,
+		s
 	}: GenerateCodeSnippets,
 	t: string,
 	externalLiveBindings: boolean,
@@ -98,12 +99,14 @@ export function getExportBlock(
 								name: null
 						  })}${name}[k]${directReturnFunctionRight}${n}${t}})`
 						: `exports[k]${_}=${_}${name}[k]`;
+					const copyPropertyIfNecessary = `{${n}${t}if${_}(k${_}!==${_}'default'${_}&&${_}!exports.hasOwnProperty(k))${_}${defineProperty}${s}${n}}`;
 					exportBlock +=
-						`Object.keys(${name}).forEach(${getFunctionIntro(['k'], {
-							isAsync: false,
-							name: null
-						})}{${n}` +
-						`${t}if${_}(k${_}!==${_}'default'${_}&&${_}!exports.hasOwnProperty(k))${_}${defineProperty}${s}${n}});`;
+						cnst === 'const'
+							? `for${_}(const k in ${name})${_}${copyPropertyIfNecessary}`
+							: `Object.keys(${name}).forEach(${getFunctionIntro(['k'], {
+									isAsync: false,
+									name: null
+							  })}${copyPropertyIfNecessary});`;
 				}
 			}
 		}

diff --git a/src/utils/interopHelpers.ts b/src/utils/interopHelpers.ts
@@ -153,6 +153,7 @@ const HELPER_GENERATORS: {
 	[MERGE_NAMESPACES_VARIABLE](t, snippets, liveBindings, freeze) {
 		const { _, directReturnFunctionRight, getDirectReturnFunctionLeft, getFunctionIntro, n } =
 			snippets;
+		// TODO Lukas use more efficient loops if we can use const and document it
 		return (
 			`function ${MERGE_NAMESPACES_VARIABLE}(n, m)${_}{${n}` +
 			`${t}m.forEach(${getDirectReturnFunctionLeft(['e'], {
@@ -194,6 +195,7 @@ const createNamespaceObject = (
 				: 'Object.create(null)'
 		};${n}` +
 		`${i}if${_}(e)${_}{${n}` +
+		// TODO Lukas use more efficient loops if we can use const and document it
 		`${i}${t}Object.keys(e).forEach(${getFunctionIntro(['k'], {
 			isAsync: false,
 			name: null

diff --git a/test/form/samples/generated-code-compact/const-bindings-false/_expected/amd.js b/test/form/samples/generated-code-compact/const-bindings-false/_expected/amd.js
diff --git a/test/form/samples/generated-code-compact/const-bindings-false/_expected/cjs.js b/test/form/samples/generated-code-compact/const-bindings-false/_expected/cjs.js
diff --git a/test/form/samples/generated-code-compact/const-bindings-false/_expected/iife.js b/test/form/samples/generated-code-compact/const-bindings-false/_expected/iife.js
diff --git a/test/form/samples/generated-code-compact/const-bindings-false/_expected/umd.js b/test/form/samples/generated-code-compact/const-bindings-false/_expected/umd.js
diff --git a/test/form/samples/generated-code-compact/const-bindings-true/_expected/amd.js b/test/form/samples/generated-code-compact/const-bindings-true/_expected/amd.js
diff --git a/test/form/samples/generated-code-compact/const-bindings-true/_expected/cjs.js b/test/form/samples/generated-code-compact/const-bindings-true/_expected/cjs.js
diff --git a/test/form/samples/generated-code-compact/const-bindings-true/_expected/iife.js b/test/form/samples/generated-code-compact/const-bindings-true/_expected/iife.js
diff --git a/test/form/samples/generated-code-compact/const-bindings-true/_expected/umd.js b/test/form/samples/generated-code-compact/const-bindings-true/_expected/umd.js
diff --git a/test/form/samples/generated-code/const-bindings-true/_expected/amd.js b/test/form/samples/generated-code/const-bindings-true/_expected/amd.js
@@ -40,12 +40,12 @@ define(['exports', 'external'], (function (exports, foo$1) { 'use strict';
 
 	exports["default"] = main;
 	exports.syntheticMissing = synthetic.syntheticMissing;
-	Object.keys(foo$1).forEach(k => {
+	for (const k in foo$1) {
 		if (k !== 'default' && !exports.hasOwnProperty(k)) Object.defineProperty(exports, k, {
 			enumerable: true,
 			get: () => foo$1[k]
 		});
-	});
+	}
 
 	Object.defineProperty(exports, '__esModule', { value: true });
 

diff --git a/test/form/samples/generated-code/const-bindings-true/_expected/cjs.js b/test/form/samples/generated-code/const-bindings-true/_expected/cjs.js
@@ -44,9 +44,9 @@ const main = 42;
 
 exports["default"] = main;
 exports.syntheticMissing = synthetic.syntheticMissing;
-Object.keys(foo$1).forEach(k => {
+for (const k in foo$1) {
 	if (k !== 'default' && !exports.hasOwnProperty(k)) Object.defineProperty(exports, k, {
 		enumerable: true,
 		get: () => foo$1[k]
 	});
-});
+}
diff --git a/test/form/samples/generated-code/const-bindings-true/_expected/iife.js b/test/form/samples/generated-code/const-bindings-true/_expected/iife.js
@@ -41,12 +41,12 @@ const bundle = (function (exports, foo$1) {
 
 	exports["default"] = main;
 	exports.syntheticMissing = synthetic.syntheticMissing;
-	Object.keys(foo$1).forEach(k => {
+	for (const k in foo$1) {
 		if (k !== 'default' && !exports.hasOwnProperty(k)) Object.defineProperty(exports, k, {
 			enumerable: true,
 			get: () => foo$1[k]
 		});
-	});
+	}
 
 	Object.defineProperty(exports, '__esModule', { value: true });
 

diff --git a/test/form/samples/generated-code/const-bindings-true/_expected/umd.js b/test/form/samples/generated-code/const-bindings-true/_expected/umd.js
@@ -49,12 +49,12 @@
 
 	exports["default"] = main;
 	exports.syntheticMissing = synthetic.syntheticMissing;
-	Object.keys(foo$1).forEach(k => {
+	for (const k in foo$1) {
 		if (k !== 'default' && !exports.hasOwnProperty(k)) Object.defineProperty(exports, k, {
 			enumerable: true,
 			get: () => foo$1[k]
 		});
-	});
+	}
 
 	Object.defineProperty(exports, '__esModule', { value: true });