@dvashim/typescript-config

TypeScript Configurations

Shareable tsconfig.json presets for libraries, React applications, and Node.js tooling — strict ES2025 + ESM defaults with bundler module resolution.

Why

These presets encode an opinionated, modern-TypeScript baseline so you don't have to re-derive it per project:

• Maximum type safety — full strict plus exactOptionalPropertyTypes, noUncheckedIndexedAccess, noUnusedLocals/noUnusedParameters, and more.
• ESM-only, bundler-first — ES2025 module output with moduleResolution: "bundler"; no downleveling or polyfilling is performed.
• Erasable-only syntax — no enums, namespaces, or parameter properties, so files transpile in isolation and stay portable across tsc, esbuild, swc, and Node's native type stripping.

They lean on TypeScript 6 defaults (strict, module: "esnext", moduleResolution: "bundler", …) rather than restating them, so the configs stay small and track upstream. Intended for greenfield ES2025 projects that ship or consume ESM on a recent toolchain — not for CommonJS, legacy targets, or projects that need enums/namespaces.

Contents

• Why
• Requirements
• Installation
• Configurations
• Usage
• Options
• Notes
• Contributing
• License

Requirements

• TypeScript >=6.0.0 (declared as a peer dependency)
• A runtime/toolchain that supports ES2025 — these presets do not downlevel or polyfill
• A bundler or a modern Node.js ESM loader — configs use moduleResolution: "bundler"

Installation

typescript is a peer dependency (>=6.0.0); it is not bundled and won't always be installed automatically (e.g. pnpm without auto-install-peers), so install it alongside this package.

npm:

npm install -D @dvashim/typescript-config typescript

or pnpm:

pnpm add -D @dvashim/typescript-config typescript

Configurations

Name	Import specifier	Use when
Base	@dvashim/typescript-config	Foundation; extend directly when composing your own preset
Library development	@dvashim/typescript-config/lib-dev	Developing a publishable library (emits .d.ts + .js, composite, source maps)
Library production	@dvashim/typescript-config/lib-prod	Release builds (extends lib-dev; strips maps, comments, @internal)
React JSX application	@dvashim/typescript-config/app-react	React app bundled by a non-Vite tool (no emit)
Vite + React JSX application	@dvashim/typescript-config/app-react-vite	React app bundled by Vite (extends app-react; adds vite/client types)
Node	@dvashim/typescript-config/node	Node.js tooling/config files, type-checked only

Not sure which one? Pick the matching extends:

{
  // Publishing a library? Use lib-dev while developing, lib-prod for release builds:
  "extends": "@dvashim/typescript-config/lib-dev",
  // Building a React app bundled by Vite:
  "extends": "@dvashim/typescript-config/app-react-vite",
  // Building a React app with another bundler:
  "extends": "@dvashim/typescript-config/app-react",
  // Type-checking Node tooling (build scripts, config files):
  "extends": "@dvashim/typescript-config/node",
  // Just need the strict ES2025 + ESM base for something else:
  "extends": "@dvashim/typescript-config"
}

Usage

Base configuration:

// tsconfig.json (Base)
// ---
// Strict ES2025 + 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, isolated declarations,
// and .ts/.tsx → .js/.jsx import rewriting on emit.

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

The lib-dev and lib-prod presets emit declarations and JavaScript and enable composite: true. Set outDir (and usually rootDir) yourself, otherwise output lands next to your sources. Because composite is on, build in build mode with tsc -b for incremental and project-reference (monorepo) builds and a .tsbuildinfo cache.

React JSX application configuration:

// tsconfig.json (React JSX application)
// ---
// Extends base for React applications.
// Adds DOM + DOM.Iterable + DOM.AsyncIterable libs,
// automatic JSX runtime, 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). Adds @types/node
// and allows .ts extension imports. Type-checked
// only (no emit) — run via a bundler or a TS-aware
// runner (Vite, tsx, esbuild).

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

Options

Base

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

Option	Value	Effect
exactOptionalPropertyTypes	true	Optional properties are strictly T | undefined
noFallthroughCasesInSwitch	true	Errors on fallthrough switch cases
noImplicitOverride	true	Requires override keyword on class member overrides
noImplicitReturns	true	Errors when not all code paths return a value
noPropertyAccessFromIndexSignature	true	Disallows dot access for index-signature-only properties
noUncheckedIndexedAccess	true	Adds undefined to index-signature access types
noUnusedLocals	true	Errors on unused local variables
noUnusedParameters	true	Errors on unused function parameters
allowUnreachableCode	false	Errors on unreachable code
allowUnusedLabels	false	Errors on unused labels
moduleDetection	"force"	All files treated as ES modules
resolveJsonModule	true	Allows importing .json files as typed modules
types	[]	Blocks ambient @types/* auto-discovery
noEmitOnError	true	Prevents emit when type errors are present
verbatimModuleSyntax	true	Preserves import/export syntax as written
isolatedModules	true	Each file can be safely transpiled in isolation
erasableSyntaxOnly	true	No enums, namespaces, or parameter properties
target	"es2025"	ES2025 JavaScript output
lib	["ES2025"]	ES2025 built-in type declarations
skipLibCheck	true	Skips type checking of .d.ts files

Library development

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

Option	Value	Effect
allowImportingTsExtensions	true	Allows .ts/.tsx extension imports in source
rewriteRelativeImportExtensions	true	Rewrites .ts/.tsx import extensions to .js/.jsx on emit
declaration	true	Emits .d.ts type declaration files
declarationMap	true	Source maps for .d.ts ("Go to Definition" navigates to source)
sourceMap	true	Generates .js.map source maps
isolatedDeclarations	true	Requires explicit type annotations on exports
composite	true	Enables project references and incremental compilation

Library production

Extends library development; strips debug artifacts for smaller, cleaner output.

Option	Value	Effect
sourceMap	false	Disables .js.map source maps
declarationMap	false	Disables .d.ts.map source maps
removeComments	true	Strips comments from emitted JavaScript
stripInternal	true	Removes @internal declarations from .d.ts output

React JSX application

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

Option	Value	Effect
allowImportingTsExtensions	true	Allows .ts/.tsx extension imports
noEmit	true	Bundler handles output
jsx	"react-jsx"	Automatic JSX runtime (no import React needed)
lib	["ES2025", "DOM", "DOM.Iterable", "DOM.AsyncIterable"]	ES2025 + DOM + iterable/async iterable DOM APIs

Vite + React JSX application

Extends React JSX application with Vite-specific type declarations.

Option	Value	Effect
types	["vite/client"]	Vite client types (import.meta.env, import.meta.hot, asset imports)

Node

Extends base for Node.js tooling files (build configs, scripts), type-checked only (noEmit). Because it keeps the inherited moduleResolution: "bundler" and allows .ts extension imports, execution is expected via a bundler or a TypeScript-aware runner (Vite, tsx, esbuild, swc). It is not tuned for Node's native type stripping (node --experimental-strip-types), which requires nodenext-style resolution and explicit file extensions — use a runner like tsx, or compile first, when running these files.

Option	Value	Effect
allowImportingTsExtensions	true	Allows .ts extension imports
types	["node"]	Node.js global and built-in module types
noEmit	true	Type-checking only; runner/bundler handles execution

Notes

• Ambient types are off by default. The base sets types: [] to block @types/* auto-discovery. If you rely on global types (e.g. node, vite/client, vitest/globals), add them to types in your own config — the node and Vite presets already do this for their cases.
• Restart the TS server after first install or after changing extends. VS Code and tsc resolve the extends package specifier from node_modules; in VS Code run "TypeScript: Restart TS Server" from the Command Palette.
• "Cannot find / read tsconfig.base.json" usually means the typescript peer dependency is not installed. See Installation.
• Layering configs. extends accepts an array, so you can compose these presets with project-specific overrides, e.g. "extends": ["@dvashim/typescript-config/node", "./tsconfig.paths.json"].

Contributing

Issues and pull requests are welcome at dvashim/typescript-config.

This project uses Changesets for versioning — run pnpm run changeset alongside your change to describe it. See the CHANGELOG for release history.

License

MIT © Aleksei Reznichenko