Use Object.values and Object.entries instead of Object.keys where useful

cli/run/build.ts

@@ -24,9 +24,7 @@ export default async function build(
 		} else if (inputOptions.input instanceof Array) {
 			inputFiles = inputOptions.input.join(', ');
 		} else if (typeof inputOptions.input === 'object' && inputOptions.input !== null) {
-			inputFiles = Object.keys(inputOptions.input)
-				.map(name => (inputOptions.input as Record<string, string>)[name])
-				.join(', ');
+			inputFiles = Object.values(inputOptions.input).join(', ');
 		}
 		stderr(cyan(`\n${bold(inputFiles!)} → ${bold(files.join(', '))}...`));
 	}

cli/run/watch-cli.ts

@@ -106,9 +106,7 @@ export async function watch(command: any) {
 						if (typeof input !== 'string') {
 							input = Array.isArray(input)
 								? input.join(', ')
-								: Object.keys(input as Record<string, string>)
-										.map(key => (input as Record<string, string>)[key])
-										.join(', ');
+								: Object.values(input as Record<string, string>).join(', ');
 						}
 						stderr(
 							cyan(`bundles ${bold(input)} → ${bold(event.output.map(relativeId).join(', '))}...`)

src/Bundle.ts

@@ -6,6 +6,7 @@ import {
 	GetManualChunk,
 	NormalizedInputOptions,
 	NormalizedOutputOptions,
+	OutputAsset,
 	OutputBundle,
 	OutputBundleWithPlaceholders,
 	OutputChunk,
@@ -41,11 +42,7 @@ export default class Bundle {
 	async generate(isWrite: boolean): Promise<OutputBundle> {
 		timeStart('GENERATE', 1);
 		const outputBundle: OutputBundleWithPlaceholders = Object.create(null);
-		this.pluginDriver.setOutputBundle(
-			outputBundle,
-			this.outputOptions,
-			this.facadeChunkByModule
-		);
+		this.pluginDriver.setOutputBundle(outputBundle, this.outputOptions, this.facadeChunkByModule);
 		try {
 			await this.pluginDriver.hookParallel('renderStart', [this.outputOptions, this.inputOptions]);
 
@@ -104,9 +101,9 @@ export default class Bundle {
 	): Promise<Map<Module, string>> {
 		const manualChunkAliasByEntry = new Map<Module, string>();
 		const chunkEntries = await Promise.all(
-			Object.keys(manualChunks).map(async alias => ({
+			Object.entries(manualChunks).map(async ([alias, files]) => ({
 				alias,
-				entries: await this.graph.moduleLoader.addAdditionalModules(manualChunks[alias])
+				entries: await this.graph.moduleLoader.addAdditionalModules(files)
 			}))
 		);
 		for (const { alias, entries } of chunkEntries) {
@@ -169,24 +166,23 @@ export default class Bundle {
 	}
 
 	private finaliseAssets(outputBundle: OutputBundleWithPlaceholders): void {
-		for (const key of Object.keys(outputBundle)) {
-			const file = outputBundle[key] as any;
+		for (const file of Object.values(outputBundle)) {
 			if (!file.type) {
 				warnDeprecation(
 					'A plugin is directly adding properties to the bundle object in the "generateBundle" hook. This is deprecated and will be removed in a future Rollup version, please use "this.emitFile" instead.',
 					true,
 					this.inputOptions
 				);
-				file.type = 'asset';
+				(file as OutputAsset).type = 'asset';
 			}
-			if (this.outputOptions.validate && typeof file.code == 'string') {
+			if (this.outputOptions.validate && typeof (file as OutputChunk).code == 'string') {
 				try {
-					this.graph.contextParse(file.code, {
+					this.graph.contextParse((file as OutputChunk).code, {
 						allowHashBang: true,
 						ecmaVersion: 'latest'
 					});
 				} catch (exception) {
-					this.inputOptions.onwarn(errChunkInvalid(file, exception));
+					this.inputOptions.onwarn(errChunkInvalid(file as OutputChunk, exception));
 				}
 			}
 		}

src/Chunk.ts

@@ -1326,8 +1326,8 @@ export default class Chunk {
 		if (!this.outputOptions.preserveModules) {
 			if (this.includedNamespaces.has(module)) {
 				const memberVariables = module.namespace.getMemberVariables();
-				for (const name of Object.keys(memberVariables)) {
-					moduleImports.add(memberVariables[name]);
+				for (const variable of Object.values(memberVariables)) {
+					moduleImports.add(variable);
 				}
 			}
 		}

src/Graph.ts

@@ -34,9 +34,9 @@ function normalizeEntryModules(
 			name: null
 		}));
 	}
-	return Object.keys(entryModules).map(name => ({
+	return Object.entries(entryModules).map(([name, id]) => ({
 		fileName: null,
-		id: entryModules[name],
+		id,
 		implicitlyLoadedAfter: [],
 		importer: undefined,
 		name
@@ -74,13 +74,14 @@ export default class Graph {
 			// increment access counter
 			for (const name in this.pluginCache) {
 				const cache = this.pluginCache[name];
-				for (const key of Object.keys(cache)) cache[key][0]++;
+				for (const value of Object.values(cache)) value[0]++;
 			}
 		}
 
 		if (watcher) {
 			this.watchMode = true;
-			const handleChange: WatchChangeHook = (...args) => this.pluginDriver.hookSeqSync('watchChange', args);
+			const handleChange: WatchChangeHook = (...args) =>
+				this.pluginDriver.hookSeqSync('watchChange', args);
 			const handleClose = () => this.pluginDriver.hookSeqSync('closeWatcher', []);
 			watcher.on('change', handleChange);
 			watcher.on('close', handleClose);
@@ -118,9 +119,9 @@ export default class Graph {
 
 		if (onCommentOrig && typeof onCommentOrig == 'function') {
 			options.onComment = (block, text, start, end, ...args) => {
-				comments.push({type: block ? "Block" : "Line", value: text, start, end});
+				comments.push({ type: block ? 'Block' : 'Line', value: text, start, end });
 				return onCommentOrig.call(options, block, text, start, end, ...args);
-			}
+			};
 		} else {
 			options.onComment = comments;
 		}
@@ -146,8 +147,8 @@ export default class Graph {
 		for (const name in this.pluginCache) {
 			const cache = this.pluginCache[name];
 			let allDeleted = true;
-			for (const key of Object.keys(cache)) {
-				if (cache[key][0] >= this.options.experimentalCacheExpiry) delete cache[key];
+			for (const [key, value] of Object.entries(cache)) {
+				if (value[0] >= this.options.experimentalCacheExpiry) delete cache[key];
 				else allDeleted = false;
 			}
 			if (allDeleted) delete this.pluginCache[name];
@@ -238,8 +239,7 @@ export default class Graph {
 
 	private warnForMissingExports() {
 		for (const module of this.modules) {
-			for (const importName of Object.keys(module.importDescriptions)) {
-				const importDescription = module.importDescriptions[importName];
+			for (const importDescription of Object.values(module.importDescriptions)) {
 				if (
 					importDescription.name !== '*' &&
 					!(importDescription.module as Module).getVariableForExportName(importDescription.name)

src/Module.ts

@@ -1002,8 +1002,7 @@ export default class Module {
 	private addModulesToImportDescriptions(importDescription: {
 		[name: string]: ImportDescription | ReexportDescription;
 	}) {
-		for (const name of Object.keys(importDescription)) {
-			const specifier = importDescription[name];
+		for (const specifier of Object.values(importDescription)) {
 			const id = this.resolvedIds[specifier.source].id;
 			specifier.module = this.graph.modulesById.get(id)!;
 		}

src/ast/keys.ts

@@ -9,7 +9,7 @@ export const keys: {
 
 export function getAndCreateKeys(esTreeNode: GenericEsTreeNode) {
 	keys[esTreeNode.type] = Object.keys(esTreeNode).filter(
-		key => key !== '_rollupAnnotations' && typeof esTreeNode[key] === 'object'
+		key => typeof esTreeNode[key] === 'object' && key !== '_rollupAnnotations'
 	);
 	return keys[esTreeNode.type];
 }

src/ast/nodes/shared/ClassNode.ts

@@ -21,14 +21,10 @@ import { ObjectEntity, ObjectProperty } from './ObjectEntity';
 import { ObjectMember } from './ObjectMember';
 import { OBJECT_PROTOTYPE } from './ObjectPrototype';
 
-// TODO Lukas
-//  * __proto__ assignment handling might be possible solely via the object prototype? But it would need to deoptimize the entire prototype chain: Bad. Better we always replace the prototype with "unknown" on assigment
-//  * __proto__: foo handling however is an ObjectExpression feature
 export default class ClassNode extends NodeBase implements DeoptimizableEntity {
 	body!: ClassBody;
 	id!: Identifier | null;
 	superClass!: ExpressionNode | null;
-
 	private classConstructor!: MethodDefinition | null;
 	private objectEntity: ObjectEntity | null = null;
 

src/ast/nodes/shared/FunctionNode.ts

@@ -13,15 +13,13 @@ import { ObjectEntity } from './ObjectEntity';
 import { OBJECT_PROTOTYPE } from './ObjectPrototype';
 import { PatternNode } from './Pattern';
 
-// TODO Lukas improve prototype handling to fix #2219
 export default class FunctionNode extends NodeBase {
 	async!: boolean;
 	body!: BlockStatement;
 	id!: IdentifierWithVariable | null;
 	params!: PatternNode[];
 	preventChildBlockScope!: true;
 	scope!: FunctionScope;
-
 	private isPrototypeDeoptimized = false;
 
 	createScope(parentScope: FunctionScope) {
@@ -42,7 +40,6 @@ export default class FunctionNode extends NodeBase {
 		}
 	}
 
-	// TODO Lukas handle other event types as well
 	deoptimizeThisOnEventAtPath(event: NodeEvent, path: ObjectPath, thisParameter: ExpressionEntity) {
 		if (event === EVENT_CALLED) {
 			if (path.length > 0 ) {

src/ast/nodes/shared/MethodBase.ts

@@ -22,7 +22,6 @@ export default class MethodBase extends NodeBase implements DeoptimizableEntity
 	private accessedValue: ExpressionEntity | null = null;
 	private accessorCallOptions: CallOptions = {
 		args: NO_ARGS,
-		// TODO Lukas in the end, handle this differently or get rid of the shared call options
 		thisParam: null,
 		withNew: false
 	};

src/ast/nodes/shared/MethodTypes.ts

@@ -76,7 +76,6 @@ export class Method extends ExpressionEntity {
 					EMPTY_PATH,
 					{
 						args: NO_ARGS,
-						// TODO Lukas check if we need something else here
 						thisParam: null,
 						withNew: false
 					},

src/ast/nodes/shared/Node.ts

@@ -195,10 +195,9 @@ export class NodeBase extends ExpressionEntity implements ExpressionNode {
 	}
 
 	parseNode(esTreeNode: GenericEsTreeNode) {
-		for (const key of Object.keys(esTreeNode)) {
+		for (const [key, value] of Object.entries(esTreeNode)) {
 			// That way, we can override this function to add custom initialisation and then call super.parseNode
 			if (this.hasOwnProperty(key)) continue;
-			const value = esTreeNode[key];
 			if (key === '_rollupAnnotations') {
 				this.annotations = value;
 			} else if (typeof value !== 'object' || value === null) {

src/ast/nodes/shared/ObjectEntity.ts

@@ -85,9 +85,9 @@ export class ObjectEntity extends ExpressionEntity {
 			return;
 		}
 		this.hasUnknownDeoptimizedInteger = true;
-		for (const key of Object.keys(this.propertiesAndGettersByKey)) {
+		for (const [key, propertiesAndGetters] of Object.entries(this.propertiesAndGettersByKey)) {
 			if (INTEGER_REG_EXP.test(key)) {
-				for (const property of this.propertiesAndGettersByKey[key]) {
+				for (const property of propertiesAndGetters) {
 					property.deoptimizePath(UNKNOWN_PATH);
 				}
 			}
@@ -421,7 +421,6 @@ export class ObjectEntity extends ExpressionEntity {
 		}
 	}
 
-	// TODO Lukas check everywhere if we can replace Object.keys with Object.entries/values
 	private deoptimizeCachedIntegerEntities() {
 		for (const [key, expressionsToBeDeoptimized] of Object.entries(
 			this.expressionsToBeDeoptimizedByKey

src/ast/variables/NamespaceVariable.ts

@@ -66,9 +66,7 @@ export default class NamespaceVariable extends Variable {
 		const t = options.indent;
 
 		const memberVariables = this.getMemberVariables();
-		const members = Object.keys(memberVariables).map(name => {
-			const original = memberVariables[name];
-
+		const members = Object.entries(memberVariables).map(([name, original]) => {
 			if (this.referencedEarly || original.isReassigned) {
 				return `${t}get ${name}${_}()${_}{${_}return ${original.getName()}${
 					options.compact ? '' : ';'

src/rollup/rollup.ts

@@ -170,9 +170,7 @@ async function handleGenerateWrite(
 				message: 'You must specify "output.file" or "output.dir" for the build.'
 			});
 		}
-		await Promise.all(
-			Object.keys(generated).map(chunkId => writeOutputFile(generated[chunkId], outputOptions))
-		);
+		await Promise.all(Object.values(generated).map(chunk => writeOutputFile(chunk, outputOptions)));
 		await outputPluginDriver.hookParallel('writeBundle', [outputOptions, generated]);
 	}
 	return createOutput(generated);
@@ -228,12 +226,9 @@ function getOutputOptions(
 
 function createOutput(outputBundle: Record<string, OutputChunk | OutputAsset | {}>): RollupOutput {
 	return {
-		output: (Object.keys(outputBundle)
-			.map(fileName => outputBundle[fileName])
-			.filter(outputFile => Object.keys(outputFile).length > 0) as (
-			| OutputChunk
-			| OutputAsset
-		)[]).sort((outputFileA, outputFileB) => {
+		output: (Object.values(outputBundle).filter(
+			outputFile => Object.keys(outputFile).length > 0
+		) as (OutputChunk | OutputAsset)[]).sort((outputFileA, outputFileB) => {
 			const fileTypeA = getSortingFileType(outputFileA);
 			const fileTypeB = getSortingFileType(outputFileB);
 			if (fileTypeA === fileTypeB) return 0;

src/utils/FileEmitter.ts

@@ -106,9 +106,12 @@ function hasValidType(
 	);
 }
 
-function hasValidName(emittedFile: { type: 'asset' | 'chunk'; [key: string]: unknown; }): emittedFile is EmittedFile {
+function hasValidName(emittedFile: {
+	type: 'asset' | 'chunk';
+	[key: string]: unknown;
+}): emittedFile is EmittedFile {
 	const validatedName = emittedFile.fileName || emittedFile.name;
-	return !validatedName || typeof validatedName === 'string' && !isPathFragment(validatedName);
+	return !validatedName || (typeof validatedName === 'string' && !isPathFragment(validatedName));
 }
 
 function getValidSource(
@@ -351,8 +354,7 @@ function findExistingAssetFileNameWithSource(
 	bundle: OutputBundleWithPlaceholders,
 	source: string | Uint8Array
 ): string | null {
-	for (const fileName of Object.keys(bundle)) {
-		const outputFile = bundle[fileName];
+	for (const [fileName, outputFile] of Object.entries(bundle)) {
 		if (outputFile.type === 'asset' && areSourcesEqual(source, outputFile.source)) return fileName;
 	}
 	return null;

src/utils/chunkAssignment.ts

@@ -185,8 +185,8 @@ function createChunks(
 			chunkModules[chunkSignature] = [module];
 		}
 	}
-	return Object.keys(chunkModules).map(chunkSignature => ({
+	return Object.values(chunkModules).map(modules => ({
 		alias: null,
-		modules: chunkModules[chunkSignature]
+		modules
 	}));
 }

src/utils/options/normalizeInputOptions.ts

@@ -187,8 +187,8 @@ const getModuleContext = (
 	}
 	if (configModuleContext) {
 		const contextByModuleId = Object.create(null);
-		for (const key of Object.keys(configModuleContext)) {
-			contextByModuleId[resolve(key)] = configModuleContext[key];
+		for (const [key, moduleContext] of Object.entries(configModuleContext)) {
+			contextByModuleId[resolve(key)] = moduleContext;
 		}
 		return id => contextByModuleId[id] || context;
 	}

src/utils/timers.ts

@@ -76,8 +76,8 @@ function timeEndImpl(label: string, level = 3) {
 
 export function getTimings(): SerializedTimings {
 	const newTimings: SerializedTimings = {};
-	for (const label of Object.keys(timers)) {
-		newTimings[label] = [timers[label].time, timers[label].memory, timers[label].totalMemory];
+	for (const [label, { time, memory, totalMemory }] of Object.entries(timers)) {
+		newTimings[label] = [time, memory, totalMemory];
 	}
 	return newTimings;
 }
@@ -102,7 +102,7 @@ function getPluginWithTimers(plugin: any, index: number): Plugin {
 				timerLabel += ` (${plugin.name})`;
 			}
 			timerLabel += ` - ${hook}`;
-			timedPlugin[hook] = function() {
+			timedPlugin[hook] = function () {
 				timeStart(timerLabel, 4);
 				let result = plugin[hook].apply(this === timedPlugin ? plugin : this, arguments);
 				timeEnd(timerLabel, 4);