refactor: 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

@@ -248,20 +248,25 @@ 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 extends Record<string, any>>(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];
+		const key = item[prop];
 		getOrCreate(lookup, key, () => {
 			const items = {
 				items: [],
@@ -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/Bundle.ts

@@ -30,8 +30,8 @@ import { basename, isAbsolute } from './utils/path';
 import { timeEnd, timeStart } from './utils/timers';
 
 export default class Bundle {
-	private facadeChunkByModule = new Map<Module, Chunk>();
-	private includedNamespaces = new Set<Module>();
+	private readonly facadeChunkByModule = new Map<Module, Chunk>();
+	private readonly includedNamespaces = new Set<Module>();
 
 	constructor(
 		private readonly outputOptions: NormalizedOutputOptions,
@@ -82,7 +82,7 @@ export default class Bundle {
 	}
 
 	private async addFinalizedChunksToBundle(
-		chunks: Chunk[],
+		chunks: readonly Chunk[],
 		inputBase: string,
 		addons: Addons,
 		outputBundle: OutputBundleWithPlaceholders,
@@ -122,11 +122,11 @@ export default class Bundle {
 	}
 
 	private assignChunkIds(
-		chunks: Chunk[],
+		chunks: readonly Chunk[],
 		inputBase: string,
 		addons: Addons,
 		bundle: OutputBundleWithPlaceholders
-	) {
+	): void {
 		const entryChunks: Chunk[] = [];
 		const otherChunks: Chunk[] = [];
 		for (const chunk of chunks) {
@@ -137,7 +137,7 @@ export default class Bundle {
 		}
 
 		// make sure entry chunk names take precedence with regard to deconflicting
-		const chunksForNaming: Chunk[] = entryChunks.concat(otherChunks);
+		const chunksForNaming = entryChunks.concat(otherChunks);
 		for (const chunk of chunksForNaming) {
 			if (this.outputOptions.file) {
 				chunk.id = basename(this.outputOptions.file);
@@ -241,7 +241,7 @@ export default class Bundle {
 	}
 
 	private prerenderChunks(
-		chunks: Chunk[],
+		chunks: readonly Chunk[],
 		inputBase: string,
 		snippets: GenerateCodeSnippets
 	): void {
@@ -254,7 +254,7 @@ export default class Bundle {
 	}
 }
 
-function getAbsoluteEntryModulePaths(chunks: Chunk[]): string[] {
+function getAbsoluteEntryModulePaths(chunks: readonly Chunk[]): string[] {
 	const absoluteEntryModulePaths: string[] = [];
 	for (const chunk of chunks) {
 		for (const entryModule of chunk.entryModules) {