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node.jstypescriptintellij-ideamocha.jsts-node

How to pass separate TypeScript config for TSNode when it has being indecency running by Mocha & IntellIJ IDEA?

Although TS-Node started the ECMAScript modules support, it has a lot of limitations and below example:

import { assert as Assert } from "chai";


describe("firstTest", (): void => {

  it("", (): void => {
    Assert.isTrue(true);
  });

});

does not work with next settings:

tsconfig.json

{
  "compilerOptions": {

    "target": "ES2020",
    "module": "ES2020",
    "moduleResolution": "node",

    "strict": true,
    "allowSyntheticDefaultImports": true,
    "experimentalDecorators": true,

    "skipLibCheck": true,

    "baseUrl": "./",
    "paths": {},

    "noUnusedParameters": true,
    "noImplicitReturns": true
  }
}

.mocharc.yaml

extension:
  - ts

spec: "**/*.test.ts"

require:
  - ts-node/register
  - tsconfig-paths/register

Error:

import { assert as Assert } from "chai";
^^^^^^

SyntaxError: Cannot use import statement outside a module

I need the ECMAScript modules because the Webpack dynamic loading does not work with CommonJS modules. So the conceptual solution is create the additional tsconfig.json for TSNode or pass modules type via console. It's has been documented how to do it for TSNode, but here I don't execute TSNode directly - I launch the Mocha via IntelliJ IDEA:

enter image description here

IntelliJ IDEA and, I suppose, all IDEs of this family including WebStorm generates the below command (added the line breaks):

"C:\Program Files\nodejs\node.exe" 
"D:\XXX\MyProject\node_modules\mocha\bin\mocha" --require ts-node/register --ui bdd --reporter C:\Users\XXX\AppData\Local\JetBrains\Toolbox\apps\IDEA-U\ch-0\203.7148.57\plugins\NodeJS\js\mocha-intellij\lib\mochaIntellijReporter.js 
"D:\XXX\MyProject\Test\Test.test.ts" --grep "^firstTest "

Now how to set CommonJS modules type?

Solution

  • According to ts-node's documentation (search for IntelliJ), you can create an alternative tsconfig.json (containing the option "module": "CommonJS") and enforce it for Mocha tests using environment variable TS_NODE_PROJECT. In the configuration corresponding to your Mocha testing, in the Environment variables section, you set this variable to the pathname of this alternative tsconfig.json. Note, multiple tsconfig.json files can use one common "base" file and extend/partially override it (see).