ts-node using with mocha and tsconfig.json

Hello and first thank you for creating this project. I bumped is a problem that seems to be discussed before but it is not clear to me what the solution is:

Here is the problem:

I was following yesterday this unit testing manual that describe one of the ways how to do unit testing with mocha and chai. It is all working as presented there but i found out that if i add my tsconfig.json to the project then the test stop working and fail with the error

It all is working if the file tsconfig.json is not in the main directory

npm run test

> external@1.0.0 test /home/tito/Projects/test
> ./node_modules/mocha/bin/mocha -r ts-node/register  ./tests/example.ts

SyntaxError: Unexpected token ] in JSON at position 475
    at JSON.parse (<anonymous>)
    at parse (/home/tito/Projects/test/node_modules/tsconfig/src/tsconfig.ts:195:15)
    at readFileSync (/home/tito/Projects/test/node_modules/tsconfig/src/tsconfig.ts:181:10)
    at Object.loadSync (/home/tito/Projects/test/node_modules/tsconfig/src/tsconfig.ts:151:18)
    at readConfig (/home/tito/Projects/test/node_modules/ts-node/src/index.ts:455:18)
    at Object.register (/home/tito/Projects/test/node_modules/ts-node/src/index.ts:205:18)
    at Object.<anonymous> (/home/tito/Projects/test/node_modules/ts-node/register/index.js:1:16)
    at Module._compile (module.js:660:30)
    at Object.Module._extensions..js (module.js:671:10)
    at Module.load (module.js:573:32)
    at tryModuleLoad (module.js:513:12)
    at Function.Module._load (module.js:505:3)
    at Module.require (module.js:604:17)
    at require (internal/module.js:11:18)
    at requires.forEach.mod (/home/tito/Projects/test/node_modules/mocha/bin/_mocha:467:3)
    at Array.forEach (<anonymous>)
    at Object.<anonymous> (/home/tito/Projects/test/node_modules/mocha/bin/_mocha:466:10)
    at Module._compile (module.js:660:30)
    at Object.Module._extensions..js (module.js:671:10)
    at Module.load (module.js:573:32)
    at tryModuleLoad (module.js:513:12)
    at Function.Module._load (module.js:505:3)
    at Function.Module.runMain (module.js:701:10)
    at startup (bootstrap_node.js:193:16)
    at bootstrap_node.js:617:3

if I rename or remove the tsconfig.json file my test a running with mocha ok and if i execute npm run test

then i get:

[  Hello function
    ✓ should return hello world
  1 passing (5ms)

and here is how the test script is being executed in package.json:

  "scripts": {
    "echo": "echo \"Error not test specified \" && exit 1",
    ......
    "server": "webpack-dev-server --watch",
    "test": "./node_modules/mocha/bin/mocha -r ts-node/register  ./tests/example.ts"
    .....
  },

I have tired adding exclude parameter to my tsconfig.json as mentioned in the issue number 4 here, but that does not seems to fix the problem i.e. here is how my tsconfig.json looks like:

{
    "compilerOptions": {
      "outDir": "./dist/",
      "sourceMap": true,
      "noImplicitAny": true,
      "module": "es6",
      "target": "es5",
      "jsx": "react",
      "allowJs": true,
      "removeComments": false

    }
    "exclude": [
        "node_modules",
        "tests",

    ]

  }

I have tired adding the dist folder to the exclude statements but that only changes the exception thrown i…e

> ./node_modules/mocha/bin/mocha -r ts-node/register  ./tests/example.ts

/home/tito/test/tests/example.ts:1
(function (exports, require, module, __filename, __dirname) { import { expect } from '../node_modules/chai';
                                                              ^^^^^^

SyntaxError: Unexpected token import
    at new Script (vm.js:51:7)
    at createScript (vm.js:138:10)
    at Object.runInThisContext (vm.js:199:10)
    at Module._compile (module.js:624:28)
    at Module.m._compile (/home/tito/test/node_modules/ts-node/src/index.ts:422:23)
    at Module._extensions..js (module.js:671:10)
    at Object.require.extensions.(anonymous function) [as .ts] (/home/tito/test/node_modules/ts-node/src/index.ts:425:12)
    at Module.load (module.js:573:32)
    at tryModuleLoad (module.js:513:12)
    at Function.Module._load (module.js:505:3)
    at Module.require (module.js:604:17)
    at require (internal/module.js:11:18)
    at /home/tito/test/node_modules/mocha/lib/mocha.js:231:27
    at Array.forEach (<anonymous>)
    at Mocha.loadFiles (/home/tito/test/node_modules/mocha/lib/mocha.js:228:14)
    at Mocha.run (/home/tito/test/node_modules/mocha/lib/mocha.js:536:10)
    at Object.<anonymous> (/home/tito/test/node_modules/mocha/bin/_mocha:582:18)
    at Module._compile (module.js:660:30)
    at Object.Module._extensions..js (module.js:671:10)
    at Module.load (module.js:573:32)
    at tryModuleLoad (module.js:513:12)
    at Function.Module._load (module.js:505:3)
    at Function.Module.runMain (module.js:701:10)
    at startup (bootstrap_node.js:193:16)
    at bootstrap_node.js:617:3

but that does not seems to solve the problem as well.

In issue number 4 it was mentioned that i should use the “–noProject” directive but how to execute that with mocha? i.e what is the command line to test with i.e. ts-node --no-project node_modules/mocha/bin/mocha -r ts-node/register ./tests/example.ts`` or ts-node --no-project node_modules/mocha/bin/_mocha -r ts-node/register ./tests/example.ts or

i do not quite understand to what should i apply that “–no-project” directive.

basically the question is how to use the ts-node correctly with mocha.

and here are some stats

node_modules/ts-node/dist$ ./bin.js --version
ts-node v4.1.0
node v9.4.0
typescript v2.6.2

any help is really appreciated.

regards,

[courteous]

got it changing node-ts does not support es6 yet, described here:

https://github.com/TypeStrong/ts-node/issues/212

changing the module parameters from

// “module”: “es6”,
“module”: “commonjs”,

worked for me, although es6 support will be nice since that is where the road is going anyway.

[KillyMXI]

This gist did the job for me: https://gist.github.com/jordansexton/2a0c3c360aa700cc9528e89620e82c3d

I can’t see “node-option” documented anywhere but it actually works and seems prettier than using node_modules internals or falling back to CommonJS.

Mocha section in package.json:

  "mocha": {
    "extension": [
      "ts"
    ],
    "node-option": [
      "experimental-specifier-resolution=node",
      "loader=ts-node/esm"
    ],
    "spec": "test/**/*.ts"
  }

ts-node section in tsconfig.json:

  "ts-node": {
    "compilerOptions": {
      "module": "ESNext",
      "esModuleInterop": true,
      "moduleResolution": "Node"
    }
  }