build: use isolated declarations

eslint.config.js

@@ -39,6 +39,7 @@ export default defineConfig(
       parserOptions: {
         sourceType: 'module',
         ecmaVersion: 2022,
+        isolatedDeclarations: true,
         project: shouldTypeCheck
           ? [
               './packages/*/tsconfig.json',

packages/plugin-legacy/src/index.ts

@@ -1004,7 +1004,7 @@ function wrapIIFEBabelPlugin(): BabelPlugin {
   }
 }
 
-export const cspHashes = [
+export const cspHashes: string[] = [
   safari10NoModuleFix,
   systemJSInlineCode,
   detectModernBrowserCode,

packages/plugin-legacy/src/snippets.ts

@@ -1,14 +1,14 @@
 // https://gist.github.com/samthor/64b114e4a4f539915a95b91ffd340acc
 // DO NOT ALTER THIS CONTENT
-export const safari10NoModuleFix = `!function(){var e=document,t=e.createElement("script");if(!("noModule"in t)&&"onbeforeload"in t){var n=!1;e.addEventListener("beforeload",(function(e){if(e.target===t)n=!0;else if(!e.target.hasAttribute("nomodule")||!n)return;e.preventDefault()}),!0),t.type="module",t.src=".",e.head.appendChild(t),t.remove()}}();`
+export const safari10NoModuleFix: string = `!function(){var e=document,t=e.createElement("script");if(!("noModule"in t)&&"onbeforeload"in t){var n=!1;e.addEventListener("beforeload",(function(e){if(e.target===t)n=!0;else if(!e.target.hasAttribute("nomodule")||!n)return;e.preventDefault()}),!0),t.type="module",t.src=".",e.head.appendChild(t),t.remove()}}();`
 
-export const legacyPolyfillId = 'vite-legacy-polyfill'
-export const legacyEntryId = 'vite-legacy-entry'
-export const systemJSInlineCode = `System.import(document.getElementById('${legacyEntryId}').getAttribute('data-src'))`
+export const legacyPolyfillId: string = 'vite-legacy-polyfill'
+export const legacyEntryId: string = 'vite-legacy-entry'
+export const systemJSInlineCode: string = `System.import(document.getElementById('${legacyEntryId}').getAttribute('data-src'))`
 
 const detectModernBrowserVarName = '__vite_is_modern_browser'
-export const detectModernBrowserDetector = `import.meta.url;import("_").catch(()=>1);(async function*(){})().next()`
-export const detectModernBrowserCode = `${detectModernBrowserDetector};window.${detectModernBrowserVarName}=true`
-export const dynamicFallbackInlineCode = `!function(){if(window.${detectModernBrowserVarName})return;console.warn("vite: loading legacy chunks, syntax error above and the same error below should be ignored");var e=document.getElementById("${legacyPolyfillId}"),n=document.createElement("script");n.src=e.src,n.onload=function(){${systemJSInlineCode}},document.body.appendChild(n)}();`
+export const detectModernBrowserDetector: string = `import.meta.url;import("_").catch(()=>1);(async function*(){})().next()`
+export const detectModernBrowserCode: string = `${detectModernBrowserDetector};window.${detectModernBrowserVarName}=true`
+export const dynamicFallbackInlineCode: string = `!function(){if(window.${detectModernBrowserVarName})return;console.warn("vite: loading legacy chunks, syntax error above and the same error below should be ignored");var e=document.getElementById("${legacyPolyfillId}"),n=document.createElement("script");n.src=e.src,n.onload=function(){${systemJSInlineCode}},document.body.appendChild(n)}();`
 
-export const modernChunkLegacyGuard = `export function __vite_legacy_guard(){${detectModernBrowserDetector}};`
+export const modernChunkLegacyGuard: string = `export function __vite_legacy_guard(){${detectModernBrowserDetector}};`

packages/plugin-legacy/tsconfig.json

@@ -1,13 +1,14 @@
 {
-  "include": ["tsdown.config.ts", "src"],
+  "include": ["src"],
   "exclude": ["**/*.spec.ts"],
   "compilerOptions": {
     "outDir": "dist",
     "target": "ES2023",
     "module": "Preserve",
     "moduleResolution": "bundler",
-    "strict": true,
+    "isolatedDeclarations": true,
     "declaration": true,
+    "strict": true,
     "sourceMap": true,
     "noUnusedLocals": true,
     "esModuleInterop": true,

packages/vite/package.json

@@ -73,7 +73,7 @@
     "build-types": "pnpm build-types-roll && pnpm build-types-check",
     "build-types-roll": "rolldown --config rolldown.dts.config.ts",
     "build-types-check": "tsc --project tsconfig.check.json",
-    "typecheck": "tsc && tsc -p src/node",
+    "typecheck": "tsc && tsc -p src/node && tsc -p src/module-runner && tsc -p src/shared && tsc -p src/node/__tests_dts__",
     "lint": "eslint --cache --ext .ts src/**",
     "format": "prettier --write --cache --parser typescript \"src/**/*.ts\"",
     "generate-target": "tsx scripts/generateTarget.ts",

packages/vite/src/client/tsconfig.json

@@ -5,6 +5,7 @@
     "types": [],
     "target": "ES2020",
     "lib": ["ESNext", "DOM"],
+    "isolatedDeclarations": false,
     "declaration": false
   }
 }

packages/vite/src/module-runner/esmEvaluator.ts

@@ -13,7 +13,8 @@ import {
 import type { ModuleEvaluator, ModuleRunnerContext } from './types'
 
 export class ESModulesEvaluator implements ModuleEvaluator {
-  public readonly startOffset = getAsyncFunctionDeclarationPaddingLineCount()
+  public readonly startOffset: number =
+    getAsyncFunctionDeclarationPaddingLineCount()
 
   async runInlinedModule(
     context: ModuleRunnerContext,

packages/vite/src/module-runner/evaluatedModules.ts

@@ -9,8 +9,8 @@ const MODULE_RUNNER_SOURCEMAPPING_REGEXP = new RegExp(
 )
 
 export class EvaluatedModuleNode {
-  public importers = new Set<string>()
-  public imports = new Set<string>()
+  public importers: Set<string> = new Set()
+  public imports: Set<string> = new Set()
   public evaluated = false
   public meta: ResolvedResult | undefined
   public promise: Promise<any> | undefined
@@ -27,9 +27,10 @@ export class EvaluatedModuleNode {
 }
 
 export class EvaluatedModules {
-  public readonly idToModuleMap = new Map<string, EvaluatedModuleNode>()
-  public readonly fileToModulesMap = new Map<string, Set<EvaluatedModuleNode>>()
-  public readonly urlToIdModuleMap = new Map<string, EvaluatedModuleNode>()
+  public readonly idToModuleMap: Map<string, EvaluatedModuleNode> = new Map()
+  public readonly fileToModulesMap: Map<string, Set<EvaluatedModuleNode>> =
+    new Map()
+  public readonly urlToIdModuleMap: Map<string, EvaluatedModuleNode> = new Map()
 
   /**
    * Returns the module node by the resolved module ID. Usually, module ID is

packages/vite/src/module-runner/runner.ts

@@ -50,7 +50,7 @@ export class ModuleRunner {
   constructor(
     public options: ModuleRunnerOptions,
     public evaluator: ModuleEvaluator = new ESModulesEvaluator(),
-    private debug?: ModuleRunnerDebugger,
+    private debug?: ModuleRunnerDebugger | undefined,
   ) {
     this.evaluatedModules = options.evaluatedModules ?? new EvaluatedModules()
     this.transport = normalizeModuleRunnerTransport(options.transport)

packages/vite/src/module-runner/tsconfig.json

@@ -1,7 +1,7 @@
 {
   "extends": "../../tsconfig.base.json",
-  "include": ["./", "../node", "../dep-types", "../types"],
-  "exclude": ["**/__tests__", "**/__tests_dts__"],
+  "include": ["./", "../node", "../types"],
+  "exclude": ["../**/__tests__", "../**/__tests_dts__"],
   "compilerOptions": {
     "lib": ["ESNext", "DOM"],
     "stripInternal": true

packages/vite/src/module-runner/utils.ts

@@ -1,7 +1,7 @@
 import * as pathe from 'pathe'
 import { isWindows } from '../shared/utils'
 
-export const decodeBase64 =
+export const decodeBase64: typeof atob =
   typeof atob !== 'undefined'
     ? atob
     : (str: string) => Buffer.from(str, 'base64').toString('utf-8')
@@ -32,8 +32,8 @@ function encodePathChars(filepath: string) {
   return filepath
 }
 
-export const posixDirname = pathe.dirname
-export const posixResolve = pathe.resolve
+export const posixDirname: (path: string) => string = pathe.dirname
+export const posixResolve: (...paths: string[]) => string = pathe.resolve
 
 export function posixPathToFileHref(posixPath: string): string {
   let resolved = posixResolve(posixPath)

packages/vite/src/node/__tests_dts__/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "isolatedDeclarations": false,
+    "declaration": false
+  },
+  "include": ["../", "../../types"],
+  "exclude": ["../**/__tests__"]
+}

packages/vite/src/node/build.ts

@@ -354,7 +354,7 @@ export interface ResolvedBuildOptions
   modulePreload: false | ResolvedModulePreloadOptions
 }
 
-export const buildEnvironmentOptionsDefaults = Object.freeze({
+const _buildEnvironmentOptionsDefaults = Object.freeze({
   target: 'baseline-widely-available',
   /** @deprecated */
   polyfillModulePreload: true,
@@ -390,7 +390,10 @@ export const buildEnvironmentOptionsDefaults = Object.freeze({
   chunkSizeWarningLimit: 500,
   watch: null,
   // createEnvironment
-})
+} satisfies BuildEnvironmentOptions)
+export const buildEnvironmentOptionsDefaults: Readonly<
+  Partial<BuildEnvironmentOptions>
+> = _buildEnvironmentOptionsDefaults
 
 export function resolveBuildEnvironmentOptions(
   raw: BuildEnvironmentOptions,
@@ -414,7 +417,7 @@ export function resolveBuildEnvironmentOptions(
 
   const merged = mergeWithDefaults(
     {
-      ...buildEnvironmentOptionsDefaults,
+      ..._buildEnvironmentOptionsDefaults,
       cssCodeSplit: !raw.lib,
       minify: consumer === 'server' ? false : 'esbuild',
       ssr: consumer === 'server',
@@ -1443,8 +1446,10 @@ export function toOutputFilePathWithoutRuntime(
   }
 }
 
-export const toOutputFilePathInCss = toOutputFilePathWithoutRuntime
-export const toOutputFilePathInHtml = toOutputFilePathWithoutRuntime
+export const toOutputFilePathInCss: typeof toOutputFilePathWithoutRuntime =
+  toOutputFilePathWithoutRuntime
+export const toOutputFilePathInHtml: typeof toOutputFilePathWithoutRuntime =
+  toOutputFilePathWithoutRuntime
 
 export class BuildEnvironment extends BaseEnvironment {
   mode = 'build' as const
@@ -1505,18 +1510,20 @@ export interface BuilderOptions {
   buildApp?: (builder: ViteBuilder) => Promise<void>
 }
 
-export const builderOptionsDefaults = Object.freeze({
+const _builderOptionsDefaults = Object.freeze({
   sharedConfigBuild: false,
   sharedPlugins: false,
   // buildApp
-})
+} satisfies BuilderOptions)
+export const builderOptionsDefaults: Readonly<Partial<BuilderOptions>> =
+  _builderOptionsDefaults
 
 export function resolveBuilderOptions(
   options: BuilderOptions | undefined,
 ): ResolvedBuilderOptions | undefined {
   if (!options) return
   return mergeWithDefaults(
-    { ...builderOptionsDefaults, buildApp: async () => {} },
+    { ..._builderOptionsDefaults, buildApp: async () => {} },
     options,
   )
 }

packages/vite/src/node/config.ts

@@ -113,7 +113,7 @@ import {
 
 const debug = createDebugger('vite:config', { depth: 10 })
 const promisifiedRealpath = promisify(fs.realpath)
-const SYMBOL_RESOLVED_CONFIG = Symbol('vite:resolved-config')
+const SYMBOL_RESOLVED_CONFIG: unique symbol = Symbol('vite:resolved-config')
 
 export interface ConfigEnv {
   /**
@@ -641,7 +641,7 @@ export interface ResolvedConfig
   > {}
 
 // inferred ones are omitted
-export const configDefaults = Object.freeze({
+const configDefaults = Object.freeze({
   define: {},
   dev: {
     warmup: [],
@@ -721,7 +721,7 @@ export const configDefaults = Object.freeze({
   envPrefix: 'VITE_',
   worker: {
     format: 'iife',
-    plugins: () => [],
+    plugins: (): never[] => [],
     // rollupOptions
   },
   optimizeDeps: {