TypeScript Configurations

Requires TypeScript >= 6.

Installation

npm:

npm install -D @dvashim/typescript-config

or pnpm:

pnpm add -D @dvashim/typescript-config

Configurations

| Name | Path | Alias | | ---- | ---- | ----- | | Base | @dvashim/typescript-config or @dvashim/typescript-config/base | — | | Library development | @dvashim/typescript-config/lib/dev or @dvashim/typescript-config/lib-dev | @dvashim/typescript-config/lib | | Library production | @dvashim/typescript-config/lib/prod or @dvashim/typescript-config/lib-prod | — | | React JSX application | @dvashim/typescript-config/app/react or @dvashim/typescript-config/app-react | @dvashim/typescript-config/app | | Vite + React JSX application | @dvashim/typescript-config/app/react/vite or @dvashim/typescript-config/app-react-vite | — | | Node | @dvashim/typescript-config/node | — |

Use

Base configuration:

// tsconfig.json (base)

// Strict ES2024 + ESM foundation with bundler resolution.
// Enforces verbatim module syntax, erasable-only syntax,
// and maximum type safety (strict, exactOptionalPropertyTypes,
// noUncheckedIndexedAccess, noUnusedLocals, etc.).

{
  "$schema": "https://json.schemastore.org/tsconfig",
  "extends": "@dvashim/typescript-config",
  "include": ["src"]
}

Library development configuration:

// tsconfig.json (library development)

// Extends base for library development.
// Enables .d.ts declarations, composite builds,
// source maps, declaration maps, and isolated declarations.

{
  "$schema": "https://json.schemastore.org/tsconfig",
  "extends": "@dvashim/typescript-config/lib-dev",
  "include": ["src"]
}

Library production configuration:

// tsconfig.json (library production)

// Extends lib-dev for production builds.
// Strips source maps, declaration maps, comments,
// and @internal declarations for minimal output.

{
  "$schema": "https://json.schemastore.org/tsconfig",
  "extends": "@dvashim/typescript-config/lib-prod",
  "include": ["src"]
}

React JSX application configuration:

// tsconfig.json (react jsx application)

// Extends base for React applications.
// Adds DOM + DOM.Iterable + DOM.AsyncIterable libs,
// automatic JSX runtime, esnext modules, and
// .ts/.tsx extension imports.
// No emit — bundler handles output.

{
  "$schema": "https://json.schemastore.org/tsconfig",
  "extends": "@dvashim/typescript-config/app-react",
  "include": ["src"]
}

Vite + React JSX application configuration:

// tsconfig.json (vite + react jsx application)

// Extends React config with Vite client types
// (import.meta.env, import.meta.hot, asset imports).

{
  "$schema": "https://json.schemastore.org/tsconfig",
  "extends": "@dvashim/typescript-config/app-react-vite",
  "include": ["src"]
}

Node configuration:

// tsconfig.json (node)

// Extends base for Node.js tooling files
// (build configs, scripts). @types/node,
// esnext modules, and .ts extension imports.
// No emit — bundler handles output.

{
  "$schema": "https://json.schemastore.org/tsconfig",
  "extends": "@dvashim/typescript-config/node",
  "include": ["vite.config.ts"]
}

Rules

Base configuration

Options listed below are set explicitly. Additional options (strict, moduleResolution: "bundler", noUncheckedSideEffectImports, forceConsistentCasingInFileNames, useDefineForClassFields, esModuleInterop) rely on TypeScript 6 defaults.

• Type Checking

  • exactOptionalPropertyTypes: true — Treats optional properties as strictly T | undefined.
  • noFallthroughCasesInSwitch: true — Reports errors for fallthrough cases in switch statements.
  • noImplicitOverride: true — Requires the override keyword when overriding class members.
  • noImplicitReturns: true — Reports errors when not all code paths in a function return a value.
  • noPropertyAccessFromIndexSignature: true — Disallows property access via dot notation when defined only by an index signature.
  • noUncheckedIndexedAccess: true — Adds undefined to types accessed via index signatures.
  • noUnusedLocals: true — Reports errors for unused local variables.
  • noUnusedParameters: true — Reports errors for unused function parameters.
  • allowUnreachableCode: false — Reports errors for unreachable code after return, throw, break, or continue.
  • allowUnusedLabels: false — Reports errors for unused labels in the code.

• Modules

  • module: es2022 — Specifies the module code generation format.
  • moduleDetection: force — Forces all files to be treated as ES modules.
  • resolveJsonModule: true — Allows importing .json files as typed modules.
  • types: [] — Disables auto-inclusion of @types/* packages; extending configs provide their own.

• Emit

  • noEmitOnError: true — Prevents emitting output files when type errors are present.

• Interop Constraints

  • verbatimModuleSyntax: true — Preserves import and export syntax exactly as written.
  • isolatedModules: true — Ensures each file can be safely transpiled in isolation.
  • erasableSyntaxOnly: true — Restricts usage to syntax that can be fully erased during compilation (no enums, namespaces, or parameter properties).

• Language and Environment

  • target: es2024 — Sets the JavaScript language version for emitted output.
  • lib: ["ES2024"] — Specifies built-in library declaration files included in compilation.

• Completeness

  • skipLibCheck: true — Skips type checking of declaration files for faster builds.

Library development configuration

Extends the base configuration with emit settings for .d.ts generation and incremental builds.

• Emit

  • declaration: true — Emits .d.ts type declaration files alongside JavaScript output.
  • declarationMap: true — Generates source maps for .d.ts files, enabling "Go to Definition" to navigate to the original source.
  • sourceMap: true — Generates .js.map source map files for debugging.

• Modules

  • types: [] — Explicitly blocks ambient @types/* auto-discovery.

• Interop Constraints

  • isolatedDeclarations: true — Requires explicit type annotations on exports so declaration files can be generated by tools other than tsc.

• Projects

  • composite: true — Enables project references and incremental compilation.

Library production configuration

Extends the library development configuration and strips debug artifacts for smaller, cleaner output.

• Emit

  • sourceMap: false — Disables .js.map source map generation.
  • declarationMap: false — Disables .d.ts.map source map generation.
  • removeComments: true — Strips comments from emitted JavaScript.
  • stripInternal: true — Removes declarations marked with @internal JSDoc tags from .d.ts output.

React JSX application configuration

Extends the base configuration for React applications with DOM types and no-emit mode.

• Modules

  • module: esnext — Uses the latest module features for bundler consumption.
  • allowImportingTsExtensions: true — Allows importing TypeScript files with explicit .ts/.tsx extensions.
  • types: [] — Explicitly blocks ambient @types/* auto-discovery.

• Emit

  • noEmit: true — Disables emitting compiled JavaScript files (bundler handles output).

• Language and Environment

  • jsx: react-jsx — Uses the automatic React JSX runtime (react/jsx-runtime), no manual import React needed.
  • lib: ["ES2024", "DOM", "DOM.Iterable", "DOM.AsyncIterable"] — Includes ES2024 APIs, DOM APIs, iterable DOM collections, and async iterable DOM APIs (e.g., ReadableStream async iteration).

Vite + React JSX application configuration

Extends the React JSX application configuration with Vite-specific type declarations.

• Modules

  • types: ["vite/client"] — Includes Vite client types (import.meta.env, import.meta.hot, asset imports). Restricts auto-included global types to only vite/client.

Node configuration

Extends the base configuration for Node.js tooling files (Vite configs, build scripts, etc.) processed by bundlers.

• Modules

  • module: esnext — Uses the latest module features for bundler consumption.
  • allowImportingTsExtensions: true — Allows importing TypeScript files with explicit .ts extensions.
  • types: ["node"] — Includes type declarations for Node.js globals and built-in modules.

• Emit

  • noEmit: true — Disables emitting compiled JavaScript files (bundler handles output).