more type fixes

browser/resolveId.ts

@@ -13,9 +13,9 @@ export async function resolveId(
 		importer: string | undefined,
 		customOptions: CustomPluginOptions | undefined,
 		isEntry: boolean | undefined,
-		skip: { importer: string | undefined; plugin: Plugin; source: string }[] | null
+		skip: readonly { importer: string | undefined; plugin: Plugin; source: string }[] | null
 	) => Promise<ResolvedId | null>,
-	skip: { importer: string | undefined; plugin: Plugin; source: string }[] | null,
+	skip: readonly { importer: string | undefined; plugin: Plugin; source: string }[] | null,
 	customOptions: CustomPluginOptions | undefined,
 	isEntry: boolean
 ): Promise<ResolveIdResult> {

build-plugins/generate-license-file.ts

@@ -1,9 +1,9 @@
-import fs from 'fs';
+import { readFileSync, writeFileSync } from 'fs';
 import { PluginImpl } from 'rollup';
 import license, { Dependency, Person } from 'rollup-plugin-license';
 
 function generateLicenseFile(dependencies: Dependency[]) {
-	const coreLicense = fs.readFileSync('LICENSE-CORE.md');
+	const coreLicense = readFileSync('LICENSE-CORE.md');
 	const licenses = new Set();
 	const dependencyLicenseTexts = dependencies
 		.sort(({ name: nameA }, { name: nameB }) => (nameA! > nameB! ? 1 : -1))
@@ -52,9 +52,9 @@ function generateLicenseFile(dependencies: Dependency[]) {
 		`${Array.from(licenses).join(', ')}\n\n` +
 		`# Bundled dependencies:\n` +
 		dependencyLicenseTexts;
-	const existingLicenseText = fs.readFileSync('LICENSE.md', 'utf8');
+	const existingLicenseText = readFileSync('LICENSE.md', 'utf8');
 	if (existingLicenseText !== licenseText) {
-		fs.writeFileSync('LICENSE.md', licenseText);
+		writeFileSync('LICENSE.md', licenseText);
 		console.warn('LICENSE.md updated. You should commit the updated file.');
 	}
 }

cli/run/batchWarnings.ts

@@ -248,17 +248,22 @@ const deferredHandlers: {
 	}
 };
 
-function title(str: string) {
+function title(str: string): void {
 	stderr(bold(yellow(`(!) ${str}`)));
 }
 
-function info(url: string) {
+function info(url: string): void {
 	stderr(gray(url));
 }
 
-function nest<T>(array: T[], prop: string) {
-	const nested: { items: T[]; key: string }[] = [];
-	const lookup = new Map<string, { items: T[]; key: string }>();
+interface Nested<T> {
+	items: T[];
+	key: string;
+}
+
+function nest<T>(array: readonly T[], prop: string): Nested<T>[] {
+	const nested: Nested<T>[] = [];
+	const lookup = new Map<string, Nested<T>>();
 
 	for (const item of array) {
 		const key = (item as any)[prop];
@@ -275,7 +280,7 @@ function nest<T>(array: T[], prop: string) {
 	return nested;
 }
 
-function showTruncatedWarnings(warnings: RollupWarning[]) {
+function showTruncatedWarnings(warnings: readonly RollupWarning[]): void {
 	const nestedByModule = nest(warnings, 'id');
 
 	const displayedByModule = nestedByModule.length > 5 ? nestedByModule.slice(0, 3) : nestedByModule;

cli/run/commandPlugins.ts

@@ -38,7 +38,10 @@ export async function addPluginsFromCommandOption(
 	}
 }
 
-async function loadAndRegisterPlugin(inputOptions: InputOptions, pluginText: string) {
+async function loadAndRegisterPlugin(
+	inputOptions: InputOptions,
+	pluginText: string
+): Promise<void> {
 	let plugin: any = null;
 	let pluginArg: any = undefined;
 	if (pluginText[0] === '{') {

cli/run/getConfigPath.ts

@@ -1,5 +1,5 @@
 import { readdirSync } from 'fs';
-import * as path from 'path';
+import { resolve } from 'path';
 import relative from 'require-relative';
 import { handleError } from '../logging';
 
@@ -8,7 +8,7 @@ const DEFAULT_CONFIG_BASE = 'rollup.config';
 export function getConfigPath(commandConfig: string | true): string {
 	const cwd = process.cwd();
 	if (commandConfig === true) {
-		return path.resolve(findConfigFileNameInCwd());
+		return resolve(findConfigFileNameInCwd());
 	}
 	if (commandConfig.slice(0, 5) === 'node:') {
 		const pkgName = commandConfig.slice(5);
@@ -28,7 +28,7 @@ export function getConfigPath(commandConfig: string | true): string {
 			}
 		}
 	}
-	return path.resolve(commandConfig);
+	return resolve(commandConfig);
 }
 
 function findConfigFileNameInCwd(): string {

cli/run/loadConfigFile.ts

@@ -1,5 +1,5 @@
-import * as fs from 'fs';
-import * as path from 'path';
+import { realpathSync } from 'fs';
+import { extname, isAbsolute } from 'path';
 import { pathToFileURL } from 'url';
 import * as rollup from '../../src/node-entry';
 import { MergedRollupOptions } from '../../src/rollup/types';
@@ -12,7 +12,7 @@ import { stderr } from '../logging';
 import batchWarnings, { BatchWarnings } from './batchWarnings';
 import { addCommandPluginsToInputOptions, addPluginsFromCommandOption } from './commandPlugins';
 
-function supportsNativeESM() {
+function supportsNativeESM(): boolean {
 	return Number(/^v(\d+)/.exec(process.version)![1]) >= 13;
 }
 
@@ -44,7 +44,7 @@ async function loadConfigFile(
 	fileName: string,
 	commandOptions: Record<string, unknown>
 ): Promise<GenericConfigObject[]> {
-	const extension = path.extname(fileName);
+	const extension = extname(fileName);
 
 	const configFileExport =
 		commandOptions.configPlugin ||
@@ -68,7 +68,7 @@ async function getDefaultFromTranspiledConfigFile(
 	const warnings = batchWarnings();
 	const inputOptions = {
 		external: (id: string) =>
-			(id[0] !== '.' && !path.isAbsolute(id)) || id.slice(-5, id.length) === '.json',
+			(id[0] !== '.' && !isAbsolute(id)) || id.slice(-5, id.length) === '.json',
 		input: fileName,
 		onwarn: warnings.add,
 		plugins: [],
@@ -102,9 +102,9 @@ async function getDefaultFromTranspiledConfigFile(
 	return loadConfigFromBundledFile(fileName, code);
 }
 
-async function loadConfigFromBundledFile(fileName: string, bundledCode: string) {
-	const resolvedFileName = fs.realpathSync(fileName);
-	const extension = path.extname(resolvedFileName);
+async function loadConfigFromBundledFile(fileName: string, bundledCode: string): Promise<unknown> {
+	const resolvedFileName = realpathSync(fileName);
+	const extension = extname(resolvedFileName);
 	const defaultLoader = require.extensions[extension];
 	require.extensions[extension] = (module: NodeModule, requiredFileName: string) => {
 		if (requiredFileName === resolvedFileName) {
@@ -132,7 +132,7 @@ async function loadConfigFromBundledFile(fileName: string, bundledCode: string)
 	}
 }
 
-async function getConfigList(configFileExport: any, commandOptions: any) {
+async function getConfigList(configFileExport: any, commandOptions: any): Promise<any[]> {
 	const config = await (typeof configFileExport === 'function'
 		? configFileExport(commandOptions)
 		: configFileExport);

cli/run/resetScreen.ts

@@ -4,7 +4,7 @@ import { stderr } from '../logging';
 const CLEAR_SCREEN = '\u001Bc';
 
 export function getResetScreen(
-	configs: MergedRollupOptions[],
+	configs: readonly MergedRollupOptions[],
 	allowClearScreen: boolean | undefined
 ): (heading: string) => void {
 	let clearScreen = allowClearScreen;

cli/run/watch-cli.ts

@@ -1,4 +1,4 @@
-import fs from 'fs';
+import { type FSWatcher, readFileSync } from 'fs';
 import chokidar from 'chokidar';
 import dateTime from 'date-time';
 import ms from 'pretty-ms';
@@ -22,17 +22,17 @@ export async function watch(command: Record<string, any>): Promise<void> {
 	let configs: MergedRollupOptions[];
 	let warnings: BatchWarnings;
 	let watcher: RollupWatcher;
-	let configWatcher: fs.FSWatcher;
+	let configWatcher: FSWatcher;
 	const configFile = command.config ? getConfigPath(command.config) : null;
 
 	onExit(close);
-	process.on('uncaughtException' as any, close);
+	process.on('uncaughtException', close);
 	if (!process.stdin.isTTY) {
 		process.stdin.on('end', close);
 		process.stdin.resume();
 	}
 
-	async function loadConfigFromFileAndTrack(configFile: string) {
+	async function loadConfigFromFileAndTrack(configFile: string): Promise<void> {
 		let reloadingConfig = false;
 		let aborted = false;
 		let configFileData: string | null = null;
@@ -42,7 +42,7 @@ export async function watch(command: Record<string, any>): Promise<void> {
 
 		async function reloadConfigFile() {
 			try {
-				const newConfigFileData = fs.readFileSync(configFile, 'utf-8');
+				const newConfigFileData = readFileSync(configFile, 'utf-8');
 				if (newConfigFileData === configFileData) {
 					return;
 				}
@@ -83,7 +83,7 @@ export async function watch(command: Record<string, any>): Promise<void> {
 
 	const resetScreen = getResetScreen(configs!, isTTY);
 
-	function start(configs: MergedRollupOptions[]) {
+	function start(configs: MergedRollupOptions[]): void {
 		try {
 			watcher = rollup.watch(configs as any);
 		} catch (err: any) {
@@ -144,7 +144,7 @@ export async function watch(command: Record<string, any>): Promise<void> {
 		});
 	}
 
-	function close(code: number | null) {
+	function close(code: number | null): void {
 		process.removeListener('uncaughtException', close);
 		// removing a non-existent listener is a no-op
 		process.stdin.removeListener('end', close);

src/Chunk.ts

@@ -108,7 +108,7 @@ function getGlobalName(
 	globals: GlobalsOption,
 	hasExports: boolean,
 	warn: WarningHandler
-) {
+): string | undefined {
 	const globalName = typeof globals === 'function' ? globals(module.id) : globals[module.id];
 	if (globalName) {
 		return globalName;
@@ -126,7 +126,7 @@ function getGlobalName(
 }
 
 export default class Chunk {
-	entryModules: Module[] = [];
+	readonly entryModules: Module[] = [];
 	execIndex: number;
 	exportMode: 'none' | 'named' | 'default' = 'named';
 	facadeModule: Module | null = null;
@@ -136,27 +136,27 @@ export default class Chunk {
 	suggestedVariableName: string;
 	variableName = '';
 
-	private accessedGlobalsByScope = new Map<ChildScope, Set<string>>();
+	private readonly accessedGlobalsByScope = new Map<ChildScope, Set<string>>();
 	private dependencies = new Set<ExternalModule | Chunk>();
-	private dynamicDependencies = new Set<ExternalModule | Chunk>();
-	private dynamicEntryModules: Module[] = [];
+	private readonly dynamicDependencies = new Set<ExternalModule | Chunk>();
+	private readonly dynamicEntryModules: Module[] = [];
 	private dynamicName: string | null = null;
-	private exportNamesByVariable = new Map<Variable, string[]>();
-	private exports = new Set<Variable>();
-	private exportsByName: Record<string, Variable> = Object.create(null);
+	private readonly exportNamesByVariable = new Map<Variable, string[]>();
+	private readonly exports = new Set<Variable>();
+	private readonly exportsByName: Record<string, Variable> = Object.create(null);
 	private fileName: string | null = null;
 	private implicitEntryModules: Module[] = [];
-	private implicitlyLoadedBefore = new Set<Chunk>();
-	private imports = new Set<Variable>();
+	private readonly implicitlyLoadedBefore = new Set<Chunk>();
+	private readonly imports = new Set<Variable>();
 	private indentString: string = undefined as never;
-	private readonly isEmpty: boolean = true;
+	private isEmpty = true;
 	private name: string | null = null;
 	private renderedDependencies: Map<ExternalModule | Chunk, ModuleDeclarationDependency> | null =
 		null;
 	private renderedExports: ChunkExports | null = null;
-	private renderedHash: string = undefined as never;
-	private renderedModuleSources = new Map<Module, MagicString>();
-	private renderedModules: {
+	private renderedHash: string | undefined = undefined;
+	private readonly renderedModuleSources = new Map<Module, MagicString>();
+	private readonly renderedModules: {
 		[moduleId: string]: RenderedModule;
 	} = Object.create(null);
 	private renderedSource: MagicStringBundle | null = null;
@@ -251,7 +251,7 @@ export default class Chunk {
 		return chunk;
 	}
 
-	canModuleBeFacade(module: Module, exposedVariables: Set<Variable>): boolean {
+	canModuleBeFacade(module: Module, exposedVariables: ReadonlySet<Variable>): boolean {
 		const moduleExportNamesByVariable = module.getExportNamesByVariable();
 		for (const exposedVariable of this.exports) {
 			if (!moduleExportNamesByVariable.has(exposedVariable)) {
@@ -429,9 +429,9 @@ export default class Chunk {
 		preserveModulesRelativeDir: string,
 		options: NormalizedOutputOptions,
 		existingNames: Record<string, unknown>,
-		unsetOptions: Set<string>
+		unsetOptions: ReadonlySet<string>
 	): string {
-		const id = this.orderedModules[0].id;
+		const [{ id }] = this.orderedModules;
 		const sanitizedId = this.outputOptions.sanitizeFileName(id);
 		let path: string;
 
@@ -641,7 +641,7 @@ export default class Chunk {
 			this.renderedSource = magicString.trim();
 		}
 
-		this.renderedHash = undefined as never;
+		this.renderedHash = undefined;
 
 		if (this.isEmpty && this.getExportNames().length === 0 && this.dependencies.size === 0) {
 			const chunkName = this.getChunkName();
@@ -811,9 +811,9 @@ export default class Chunk {
 	}
 
 	private addDependenciesToChunk(
-		moduleDependencies: Set<Module | ExternalModule>,
+		moduleDependencies: ReadonlySet<Module | ExternalModule>,
 		chunkDependencies: Set<Chunk | ExternalModule>
-	) {
+	): void {
 		for (const module of moduleDependencies) {
 			if (module instanceof Module) {
 				const chunk = this.chunkByModule.get(module);
@@ -826,7 +826,7 @@ export default class Chunk {
 		}
 	}
 
-	private assignFacadeName({ fileName, name }: FacadeName, facadedModule: Module) {
+	private assignFacadeName({ fileName, name }: FacadeName, facadedModule: Module): void {
 		if (fileName) {
 			this.fileName = fileName;
 		} else {
@@ -870,7 +870,7 @@ export default class Chunk {
 		hash.update(
 			[addons.intro, addons.outro, addons.banner, addons.footer].map(addon => addon || '').join(':')
 		);
-		hash.update(options.format as string);
+		hash.update(options.format);
 		const dependenciesForHashing = new Set<Chunk | ExternalModule>([this]);
 		for (const current of dependenciesForHashing) {
 			if (current instanceof ExternalModule) {
@@ -1306,7 +1306,7 @@ export default class Chunk {
 				break;
 			}
 		}
-		const usedNames = new Set<string>(['Object', 'Promise']);
+		const usedNames = new Set(['Object', 'Promise']);
 		if (this.needsExportsShim) {
 			usedNames.add(MISSING_EXPORT_SHIM_VARIABLE);
 		}

src/ModuleLoader.ts

@@ -176,7 +176,7 @@ export class ModuleLoader {
 		importer: string | undefined,
 		customOptions: CustomPluginOptions | undefined,
 		isEntry: boolean | undefined,
-		skip: { importer: string | undefined; plugin: Plugin; source: string }[] | null = null
+		skip: readonly { importer: string | undefined; plugin: Plugin; source: string }[] | null = null
 	): Promise<ResolvedId | null> => {
 		return this.addDefaultsToResolvedId(
 			this.getNormalizedResolvedIdWithoutDefaults(

src/utils/PluginDriver.ts

@@ -69,19 +69,19 @@ function throwInvalidHookError(hookName: string, pluginName: string) {
 }
 
 export class PluginDriver {
-	public emitFile: EmitFile;
+	public readonly emitFile: EmitFile;
 	public finaliseAssets: () => void;
 	public getFileName: (fileReferenceId: string) => string;
-	public setOutputBundle: (
+	public readonly setOutputBundle: (
 		outputBundle: OutputBundleWithPlaceholders,
 		outputOptions: NormalizedOutputOptions,
 		facadeChunkByModule: Map<Module, Chunk>
 	) => void;
 
-	private fileEmitter: FileEmitter;
-	private pluginCache: Record<string, SerializablePluginCache> | undefined;
-	private pluginContexts = new Map<Plugin, PluginContext>();
-	private plugins: Plugin[];
+	private readonly fileEmitter: FileEmitter;
+	private readonly pluginCache: Record<string, SerializablePluginCache> | undefined;
+	private readonly pluginContexts = new Map<Plugin, PluginContext>();
+	private readonly plugins: Plugin[];
 
 	constructor(
 		private readonly graph: Graph,