Observe side-effects in second argument of Array.from

src/Chunk.ts

@@ -291,13 +291,13 @@ export default class Chunk {
 			}
 		}
 		for (const module of this.entryModules) {
-			const requiredFacades: FacadeName[] = [...module.userChunkNames].map(name => ({
+			const requiredFacades: FacadeName[] = Array.from(module.userChunkNames, name => ({
 				name
 			}));
 			if (requiredFacades.length === 0 && module.isUserDefinedEntryPoint) {
 				requiredFacades.push({});
 			}
-			requiredFacades.push(...[...module.chunkFileNames].map(fileName => ({ fileName })));
+			requiredFacades.push(...Array.from(module.chunkFileNames, fileName => ({ fileName })));
 			if (requiredFacades.length === 0) {
 				requiredFacades.push({});
 			}
@@ -416,7 +416,7 @@ export default class Chunk {
 	}
 
 	getDynamicImportIds(): string[] {
-		return [...this.dynamicDependencies].map(chunk => chunk.id as string);
+		return Array.from(this.dynamicDependencies, chunk => chunk.id as string);
 	}
 
 	getExportNames(): string[] {
@@ -426,7 +426,7 @@ export default class Chunk {
 	}
 
 	getImportIds(): string[] {
-		return [...this.dependencies].map(chunk => chunk.id as string);
+		return Array.from(this.dependencies, chunk => chunk.id as string);
 	}
 
 	getRenderedHash(outputPluginDriver: PluginDriver): string {

src/Module.ts

@@ -717,7 +717,7 @@ export default class Module {
 			ast: this.esTreeAst,
 			code: this.code,
 			customTransformCache: this.customTransformCache,
-			dependencies: [...this.dependencies].map(module => module.id),
+			dependencies: Array.from(this.dependencies, module => module.id),
 			id: this.id,
 			moduleSideEffects: this.moduleSideEffects,
 			originalCode: this.originalCode,

src/ModuleLoader.ts

@@ -234,7 +234,7 @@ export class ModuleLoader {
 
 	private fetchAllDependencies(module: Module): Promise<unknown> {
 		return Promise.all([
-			...[...module.sources].map(async source => {
+			...Array.from(module.sources, async source => {
 				const resolution = await this.fetchResolvedDependency(
 					source,
 					module.id,

src/ast/nodes/shared/knownGlobals.ts

@@ -76,7 +76,7 @@ const knownGlobals: GlobalDescription = {
 		// @ts-ignore
 		__proto__: null,
 		[ValueProperties]: IMPURE,
-		from: PF,
+		from: O,
 		isArray: PF,
 		of: PF,
 		prototype: O

test/function/samples/array-from-side-effect/_config.js

@@ -0,0 +1,8 @@
+const assert = require('assert');
+
+module.exports = {
+	description: 'Observes side-effects in Array.from',
+	exports(exports) {
+		assert.strictEqual(exports.x, 7);
+	}
+};

test/function/samples/array-from-side-effect/main.js

@@ -0,0 +1,3 @@
+export let x = 1;
+const list = [1, 2, 3];
+Array.from(list, v => (x += v));