SWC uses @swc/helpers instead of tslib. This feature is meant to facilitate scenarios where normal compilerOptions and package.json configuration is not possible.

In many cases, setting NODE_OPTIONS will enable ts-node within other node tools, child processes, and worker threads.

This configuration is necessary if your package.json has "type": "module". Node's ESM loader hooks are experimental and subject to change. moduleTypes achieves the same effect for .ts and .js files, and also overrides your tsconfig.json "module" The compiler must transform this syntax via "downleveling," which is controlled by Environment: TS_NODE_LOG_ERROR, Default: false To write scripts with maximum portability, specify options in your tsconfig.json and omit them from the shebang. node flags must be passed directly to node; they cannot be passed to the ts-node binary nor can they be specified in tsconfig.json. @tsconfig/bases maintains recommended configurations for several node versions. Environment: TS_NODE_SCOPE. Wherever possible, it is recommended to use TypeScript's NodeNext or Node16 mode instead of the options described and require that file to execute as CommonJS. Available from 4.7+, the node16 and nodenext modes integrate with Nodes native ECMAScript Module support. ts-node will import the pre-compiled JavaScript. The emitted JavaScript uses either CommonJS or ES2020 output depending on the file extension and the value of the type setting in the nearest package.json. If you are unsure which configuration is used, you can log it with ts-node --showConfig.

When executing TypeScript with npx or yarn dlx, the code resides within a temporary node_modules directory. Our hook runs in the middle, transforming code from TypeScript to JavaScript and passing the result to node for execution. We refer to this mechanism as "scoping." Connect and share knowledge within a single location that is structured and easy to search. TypeScript is almost always written using modern import syntax, but it is also transformed before being executed by the underlying runtime. These are the same as errors you get from tsc. How did this note help previous owner of this old film camera?

Override the module type of certain files, ignoring the package.json "type" field. For global definitions, you can use the typeRoots compiler option. If you use "target": "esnext", then the following TypeScript syntax: When you try to run this code, node 12 will throw a SyntaxError. ts-node supports --project and --showConfig similar to the tsc CLI. Default: false Note: --watch-extensions is only used in --watch mode.

ts-node will always resolve the compiler from cwd before checking relative to its own installation. Alternatively, you can invoke node directly and install ts-node via --require/-r. All command-line flags support both --camelCase and --hyphen-case. Making statements based on opinion; back them up with references or personal experience. transpiler must be given the If a file requires transformation but is ignored, node may either fail to resolve it or attempt to execute it as vanilla JavaScript. Note that ts-node-dev is incompatible with our native ESM loader. You can use ts-node together with tsconfig-paths to load modules according to the paths section in tsconfig.json.

US to Canada by car with an enhanced driver's license, no passport? Note: If you are using the --project command line argument as per the Configuration Options, and want to apply this same behavior when launching in IntelliJ, specify under "Environment Variables": TS_NODE_PROJECT=.

Note: --esm must spawn a child process to pass it --loader. By default, this search is performed relative to the entrypoint script. This tells any node processes which receive this environment variable to install ts-node's hooks before executing other code.

To force ts-node to import the TypeScript source, not the precompiled JavaScript, use --preferTsExts. You must also ensure node is passed --loader. Find centralized, trusted content and collaborate around the technologies you use most. This may cause syntax errors or other failures, because node does not understand TypeScript type syntax nor bleeding-edge ECMAScript features. Environment: TS_NODE_FILES, Ignore TypeScript warnings by diagnostic code, Override the path patterns to skip compilation, Default: /node_modules/ If you are not using our CLI, pass the loader flag to node. Trending is based off of the highest score sort and falls back to it if no posts are trending.

The instances are used to transform Node.js license information, ts-node includes source code from the TypeScript compiler which is licensed under the Apache License 2.0. You can run tsc --noEmit to do this. (instead of occupation of Japan, occupied Japan or Occupation-era Japan), JavaScript front end for Odin Project book library database. sourcemap support, and global ts-node CLI. tools and libraries. Solution: downgrade the dependency to an older, CommonJS version. The following example tells ts-node to execute a webpack config as CommonJS: Each key is a glob pattern with the same syntax as tsconfig's "include" array. We recommend this because it works even when you cannot pass CLI flags, such as node --require ts-node/register and when using shebangs. If you are invoking node directly, you can avoid the environment variable and pass those flags to node. This may be helpful if you prefer not to change your compilerOptions or structure your type definitions for typeRoots. TypeScript execution and REPL for node.js, with source map and native ESM support. Use --project to explicitly specify the path to a tsconfig.json. See Missing types for details. Most ts-node options can be specified in a "ts-node" object using their programmatic, camelCase names. within a directory. name of a module which can be require()d. The built-in swc plugin is exposed as ts-node/transpilers/swc. Watching files and code reloads are out of scope for the project. Proof that When all the sides of two triangles are congruent, the angles of those triangles must also be congruent (Side-Side-Side Congruence). The difference between "require(x)" and "import x", Understanding esModuleInterop in tsconfig file, Angular: 7.2.1 ES6 class ReferenceError : Cannot access 'X' before initialization, Cardboard box giving me strange mesh errors, Sum of Convergent Series for Problem Like Schrdingers Cat, Short story about the creation of a spell that creates a copy of a specific woman.

Ignoring a file means we do not transform it from TypeScript into JavaScript, but it does not prevent execution. In the TypeScript 2.0 release notes, it says: "Previously flagged as an invalid flag combination, target: es5 and module: es6 is now supported. To learn more, see our tips on writing great answers. Environment: TS_NODE_TYPE_CHECK, Default: false ts-node's complete API is documented here: API Docs. This may change if node adds the ability to install loader hooks Here are a few highlights of what you can accomplish: ts-node focuses on adding first-class TypeScript support to node. Environment: TS_NODE_EMIT.

This is accomplished by hooking node's module loading APIs, enabling it to be used seamlessly alongside other Node.js This error is thrown by node when a module is require()d, but node believes it should execute as native ESM. The API includes additional options not shown here. Solution: Configure a module type override. Was there a Russian safe haven city for politicians and scientists?

In rare cases, you may need to override this behavior for some files. You will need to force the config and In many cases, setting NODE_OPTIONS will enable ts-node within other node tools, child processes, and worker threads. Vanilla node loads .js by reading code from disk and executing it.

You can now choose to sort by Trending, which boosts votes that have happened recently, helping to surface more up-to-date answers. Here you have specified using the ES2015 module system, so that enables the ES6 module syntax. // Remove if you want ts-node to do typechecking. As a convenience, these are bundled with ts-node. This makes it an order of magnitude faster than vanilla transpileOnly.

Wherever possible you should favor using traditional package.json and tsconfig.json configurations. This means TypeScript files are transformed according to your tsconfig.json "module" This can be combined with other node flags. Modules should always be published in a format node.js can consume, Transpiling the entire dependency tree will make your project slower, Differing behaviours between TypeScript and node.js (e.g. Older versions of typescript are incompatible with @tsconfig/node16. These are bugs in your code or configuration.

Environment: TS_NODE_SCOPE_DIR. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. SWC support is built-in via the --swc flag or "swc": true tsconfig option. Typescript target not affecting source javascript files (with allowJs)? ts-node's ESM support is as stable as possible, but it relies on APIs which node can and will break in new versions of node. Solution: configure your project to compile and execute as native ESM. into something node can understand. Plugins automatically derive an appropriate configuration from your existing In --cwdMode or if no entrypoint is specified -- for example when using the REPL -- the search is performed relative to --cwd / process.cwd(). For example: ts-node automatically finds and loads tsconfig.json. // ts-node options are read from tsconfig.json, // This shebang works on Mac and Linux with newer versions of env, // Technically, Mac allows omitting `-S`, but Linux requires it. Set "module": "NodeNext" and everything should work.

This transformation will respect your tsconfig.json as if you had compiled via tsc. Prints the version. The TypeScript compiler has a set of additional flags to inform the compiler of transformations that are expected to happen to the sources to generate the final output. much faster than the TypeScript compiler. See how TypeScript improves day to day working with JavaScript with minimal additional syntax. optional chaining operator. You can choose to either transform to CommonJS or to preserve the native import syntax, using node's native ESM support.

Tip: Installing modules locally allows you to control and share the versions through package.json.

ts-node is a TypeScript execution engine and REPL for Node.js. When searching, it is resolved using the same search behavior as tsc. You have a mix of CommonJS and native ESM in your project, Solution: double-check all package.json "type" and tsconfig.json "module" configuration, Solution: consider simplifying by making your project entirely CommonJS or entirely native ESM, You are using a tool which has an extensionless binary, such as. Scope compiler to files within scopeDir. Or specify options via your mocha config file. option and executed according to node's rules for the package.json "type" field. // different options with a single tsconfig.json. CommonJS supports extensionless files but native ESM does not. Thus it is not recommended for production.

If you have package.json configured with "type": "module" and tsconfig.json with

For example, ttypescript and ts-patch implement the same API. TypeScript execution and REPL for node.js.

This is because a large majority of projects do not use all of the files in a project directory (e.g. in this section. This may

When ts-node is used with allowJs, all non-ignored JavaScript files are transformed by ts-node. .js and .jsx are only transformed when allowJs is enabled. Do any of these flags define in what language and module system the compiled code is output, or are these flags only to determine how the input source should be parsed?

Plugins are require()d by ts-node, so they can be a local script or a node module published to npm. This will only affect rare cases such as using const enums with preserveConstEnums disabled. ts-node supports a variety of options which can be specified via tsconfig.json, as CLI flags, as environment variables, or programmatically. ts-node index.ts) and TypeScript resolves dependencies based on imports and references. Environment: TS_NODE_COMPILER, Transpile with swc. Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Transforming to CommonJS is typically simpler and more widely supported because it is older. // Most ts-node options can be specified here using their programmatic names. With the latest node and typescript, this is @tsconfig/node16. But the javascript code that is generated is having import / export statements even though the target is es5 , how is it possible ? any supporting scripts to execute as CommonJS. Heres some example output for this file: If you are wondering about the difference between ES2015 (aka ES6) and ES2020, ES2020 adds support for dynamic imports, and import.meta. In these situations, our moduleTypes option can override certain files to be 465), Design patterns for asynchronous API communication. Create a new Node.js debug configuration, add -r ts-node/register to node args and move the program to the args list (so VS Code doesn't look for outFiles). Some projects require a patched typescript compiler which adds additional features. have one. TranspilerModule interface. add the ability to configure custom transformers. Disable top-level await in REPL. // Or install directly with `npm i -D @tsconfig/node16`, // This can be omitted; commonjs is the default, // Tell ts-node CLI to install the --loader automatically, explained below, /// , // Do not forget to `npm i -D tsconfig-paths`, // This can be omitted when using ts-patch, // plugin configuration is the same for both ts-patch and ttypescript, // Globs are also supported with the same behavior as tsconfig "include". Type errors from the compiler are thrown as a TSError. Note the uppercase -P. This is different from tsc's -p/--project option. Environment: TS_NODE_PRETTY, Behave as if invoked in this working directory, Default: process.cwd() Default: false

For example, to use a hypothetical "@cspotcode/fast-ts-compiler", first install it into your project: npm install @cspotcode/fast-ts-compiler. You have installed an ESM dependency but your own code compiles to CommonJS. The JavaScript itself may target ES5, and use only ES5 features, but it is theoretically possible to use a module loader with that code that operates with ES2015 module syntax. In other words, they intend us to write our imports in a way node already understands. Environment: TS_NODE_SKIP_IGNORE, Default: typescript If you want to restart the ts-node process on file change, existing node.js tools such as nodemon, onchange and node-dev work. ts-node is licensed under the MIT license. You have moved your project to ESM but still have a config file, such as, Solution: if supported by the relevant tool, rename your config file to.