node-typescript-compiler

node-typescript-compiler

Exposes the TypesScript compiler (tsc) as a node.js module

Allows you to invoke tsc from a node script.

This work trivially by spawning tsc from whenever it can be found, ideally a sibling ../node_modules/typescript module.

Example use case: I'm using this to build several variants of my modules = node / browser, calling tsc with slight modifications of target and lib.

Note to evaluators: This module is solidly built (not a hack), it works in a straightforward and reliable way and will properly catch and report any possible error. Usage in production is thus possible.

installation

node-typescript-compiler requires the typescript module as a sibling, not included so you can choose your version. (node-typescript-compiler will intelligently try to locate another typescript install if it can't be found as a sibling. This is not recommended)

npm i --save-dev typescript
npm i --save-dev node-typescript-compiler

Node requirements: >=12 since this module is now pure ESM. If needed, the older v3 should work for older node >=4. Not promising anything.

Usage

WARNING You should have a working TypeScript setup with a tsc+tsconfig.json before using this tool. It'll be easier to know where the errors are from: your setup or this tool?

The module exposes a unique function, compile({tscOptions}, [files], [{options}]):

• tscOptions is a hashmap of tsc options
  • Note: you're better re-using a tsconfig.json and using just { project: '.' } to refer to it
• files is an optional array of files to compile, if not implied through tscOptions (force it to undefined if you need the 3rd param)
• options is an optional hash of:
  • verbose: boolean (default false) explain what's happening and display more detailed errors
  • banner: string (default node-typescript-compiler:) what is displayed as the first line of stdout

Example invocation: Compile current project:

import tsc from 'node-typescript-compiler'
await tsc.compile({
	'project': '.'
})

--> Will spawn tsc --project .

Example invocation: Compile current project with some options overridden

import tsc from 'node-typescript-compiler'
const tsconfig = { json: require('../tsconfig.json') }

await tsc.compile(
	{
		...tsconfig.json.compilerOptions,
		declaration: false,
		outDir: 'dist/es6.amd',
		module: 'amd'
	},
	tsconfig.json.files,
)

--> Will spawn tsc <…non-overriden tsconfig options> --outDir dist/es6.amd --module amd (boolean "false" values cause the corresponding option to not be added to the invocation string, this is the intended behaviour)

Example invocation: Get help

import tsc from 'node-typescript-compiler'

await tsc.compile({
	help: true
})

--> Will spawn tsc --help (boolean "true" values are not needed thus don't appear on the invocation string, option presence is enough)

Usage notes

This module should be fairly stable. Its behaviour is straightforward and all possible error cases should be caught.

This module will intelligently try to extract the error message from stdout/stderr if possible.

Output is forwarded, with a radix: tsc>

The output is monitored and on detection of an incremental recompilation, a convenient separator will be displayed.

Also the --listFiles option should lead to a readable output.

This module should work on Windows thanks to using the cross-spawn package. However this has NOT been tested personally by the author.

Design considerations

It seems we could do that more elegantly and at a lower level by directly calling tsc code, as explained here: https://basarat.gitbooks.io/typescript/content/docs/compiler/overview.html

However, that would take a lot of time and effort, and I'm afraid of API changes. So no.

See also

https://www.npmjs.com/package/ntypescript but they have poor doc and don't allow choosing the typescript version (ex. using the unstable "next")