How to run Mocha tests written in TypeScript?

node.js typescript mocha
Thomas picture Thomas · Nov 17, 2014 · Viewed 20.8k times · Source

Setup: I have a Node project (pure Node, no browser bits) written in TypeScript. I can use the TypeScript compiler (tsc) from the typescript module to compile the code. So far so good.

However, I want to write tests using Mocha, and that's where I'm having trouble. I tried --compilers ts:typescript, but I keep getting errors like:

error TS5023: Unknown compiler option 'compilers'.

It looks like the command line to mocha ends up being passed to tsc, which is obviously not good.

Answer

jpierson picture jpierson · Feb 26, 2016

For anybody who has tried and had problems with typescript-require you may want to try ts-node. 

$ npm install -g ts-node
$ mocha test.ts --require ts-node/register src/**/*.spec.ts

It also appears that there has been some ongoing discussion about deprecating typescript-require in favor of ts-node.

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