在Mocha测试中使用带有ts-node的assert

Question

I created a mocha test in a test.ts

import * as assert from "assert";

describe('it', () => {
  it('should ', done => {
    assert.strictEqual(true, false);
    done();
  });
});

My package.json s devDependencies :

"devDependencies": {
    "@types/mocha": "^5.2.5",
    "@types/node": "^10.12.18",
    "mocha": "^5.2.0",
    "ts-node": "^8.0.1",
    "typescript": "^3.2.4"
  }

tsconfig.json :

{
  "compilerOptions": {
    "target": "es2015",
    "module": "commonjs",
    "sourceMap": true,
    "declaration": true,
    "outDir": "./dist",
    "strict": true,
    "types": ["mocha"]
  }
}

When running ts-node , I get this error:

error TS2307: Cannot find module 'assert'.

My commandline call is this:

./node_modules/mocha/bin/mocha -r ts-node/register test/test.ts

Regular tsc throws no errors.

Answer 1

Solved it via this issue comment on GitHub:

types in tsconfig.json needs to include node :

{
  "compilerOptions": {
    "target": "es2015",
    "module": "commonjs",
    "sourceMap": true,
    "declaration": true,
    "outDir": "./dist",
    "strict": true,
    "types": ["mocha", "node"]
  }
}