TypeScript Node

TypeScript execution environment and REPL for node. Works with typescript@>=1.5.

Installation

npm install -g ts-node

# Install a TypeScript compiler (requires `typescript` by default).
npm install -g typescript

Features

• Execute TypeScript files with node
• Interactive REPL
• Execute (and print) TypeScript through the CLI
• Uses source maps
• Loads compiler options and .d.ts files from tsconfig.json

Usage

# Execute a script as you would normally with `node`.
ts-node script.ts

# Starts the TypeScript REPL.
ts-node

# Execute code with TypeScript.
ts-node -e 'console.log("Hello, world!")'

# Execute, and print, code with TypeScript.
ts-node -p '"Hello, world!"'

# Pipe scripts to execute with TypeScript.
echo "console.log('Hello, world!')" | ts-node

Programmatic

You can require ts-node and register the loader for future requires by using require('ts-node').register({ /* options */ }). You can also use the shortcut files node -r ts-node/register or node -r ts-node/register/type-check depending on your preferences.

Mocha

mocha --require ts-node/register --watch-extensions ts,tsx "test/**/*.{ts,tsx}" [...args]

Note: --watch-extensions is only used in --watch mode.

Tape

ts-node node_modules/tape/bin/tape [...args]

Gulp

# Just create a `gulpfile.ts` and run `gulp`.
gulp

How It Works

TypeScript Node works by registering the TypeScript compiler for the .ts, .tsx and - when allowJs is enabled - .js extensions. When node.js has a file extension registered (the require.extensions object), it will use the extension internally with module resolution. By default, when an extension is unknown to node.js, it will fallback to handling the file as .js (JavaScript).

P.S. This means that if you don't register an extension, it'll be compiled as JavaScript. When ts-node is used with allowJs, JavaScript files are transpiled using the TypeScript compiler.

Loading tsconfig.json

Typescript Node uses tsconfig.json automatically, use --no-project to skip loading tsconfig.json.

NOTE: You can use ts-node together with tsconfig-paths to load modules according to the paths section in tsconfig.json.

Configuration Options

You can set options by passing them in before the script.

Note: These are in addition to the node.js CLI arguments.

ts-node --compiler ntypescript --project src --ignoreWarnings 2304 hello-world.ts

• --project, -P Path to load TypeScript configuration from (JSON file, a directory containing tsconfig.json, or --no-project/false to disable) (also process.env.TS_NODE_PROJECT)
• --compiler, -C Use a custom, require-able TypeScript compiler compatible with typescript@>=1.5.0-alpha (also process.env.TS_NODE_COMPILER)
• --ignore Specify an array of regular expression strings for ts-node to skip compiling as TypeScript (defaults to /node_modules/, --no-ignore/false to disable) (also process.env.TS_NODE_IGNORE)
• --ignoreWarnings, -I Set an array of TypeScript diagnostic codes to ignore (also process.env.TS_NODE_IGNORE_WARNINGS)
• --compilerOptions, -O Set compiler options using JSON (E.g. --compilerOptions '{"target":"es6"}') (also process.env.TS_NODE_COMPILER_OPTIONS)
• --type-check Use TypeScript with type checking (also process.env.TS_NODE_TYPE_CHECK)
• --no-cache Skip hitting the compiled JavaScript cache (also process.env.TS_NODE_CACHE)
• --cache-directory Configure the TypeScript cache directory (also process.env.TS_NODE_CACHE_DIRECTORY)

Additionally, the transformers option may be provided when programmatically registering ts-node to specify custom TypeScript transformers.

License

MIT