Is there source map support for typescript in node / nodemon?

Question

I have a node project written in typescript@2.

My tsconfig has sourceMap set to true and the *.map.js files are generated. When I execute my transpiled *.js JavaScript files via node or nodemon, I only see the error messages relative to the js file and not to the mapped typescript files; I assume it's completely ignored.

Is sourceMap support only intended for browser-support? Or can I use it together with node or nodemon? If the latter, how would I enable it?

I want to see runtime errors detected from an executed javascript file relative to the original typescript file.

Answer 1

🚩 for Node versions since v12.12, there is an easier and better solution.

I recently got this working in my express app. Steps as follows:

Install the required library:

npm install --save-dev source-map-support

In your entry point (eg app.ts):

require('source-map-support').install();

In your app.ts, you may also require better logging for errors within promises:

process.on('unhandledRejection', console.log);

In your tsconfig, under compilerOptions:

"inlineSourceMap": true

Answer 2

Install source map support:

npm install source-map-support 

(I run in in production as well, as it immensely helps finding bugs from the logs of when an error an occurs. I did not experience a large performance impact, yet your experience may be different.)

Add to your tsconfig.json:

{    "compilerOptions": {       "sourceMap": true    } } 

When running your JavaScript file, add the require parameter:

nodemon -r source-map-support/register dist/pathToJson.js  node -r source-map-support/register dist/pathToJson.js 

Alternatively, you add in your entry call:

require('source-map-support').install() 

yet I find this tedious is projects with multiple entry points.

---

Sidenote: mocha also supports the --require / -r option, so to have the sourcemap support in mocha you can also call your tests with it, e.g. similar to:

NODE_ENV=test npx mocha --forbid-only --require source-map-support/register --exit --recursive ./path/to/your/tests/