Custom matcher is not recognized (TS2339) on the running with ---no-cache

[mugifly]

Hi there.
I tried to make a custom matcher with ts-jest, however it doesn't recognize it well.
Apparently, it throws an error when running jest with --no-cache.
On the other hand, without --no-cache (if there is a cache?) it works correctly.

Could you tell me the right way please?
Here is the simplest code that doesn't work...

Log:

$ npm run test -- --no-cache

> tmp@1.0.0 test /home/masanori/tmp
> jest "--no-cache"

 FAIL  src/index.spec.ts
  ● Test suite failed to run

    src/index.spec.ts:6:17 - error TS2339: Property 'toBeFoo' does not exist on type 'Matchers<string>'.

    6   expect("foo").toBeFoo();
                      ~~~~~~~

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        4.407 s
Ran all test suites.
...

$ npm run test 

> tmp@1.0.0 test /home/masanori/tmp
> jest

 PASS  src/index.spec.ts
  ✓ foo (3 ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        1.397 s
Ran all test suites.

src/index.spec.ts:

import { expect } from "@jest/globals";

import "./matcher";

test("foo", async () => {
  expect("foo").toBeFoo();
});

src/matcher.ts:

import { expect } from "@jest/globals";

declare global {
  namespace jest {
    interface Matchers<R> {
      toBeFoo(): R;
    }
  }
}

expect.extend({
  toBeFoo(received: string) {
    if (received == "foo") {
      return {
        message: () => "OK",
        pass: true,
      };
    } else {
      return {
        message: () => "NG",
        pass: false,
      };
    }
  },
});

package.json:

{
  "name": "tmp",
  "version": "1.0.0",
  "description": "",
  "scripts": {
    "test": "jest"
  },
  "jest": {
    "preset": "ts-jest",
    "setupFilesAfterEnv": [
      "<rootDir>/src/matcher.ts"
    ]
  },
  "dependencies": {},
  "devDependencies": {
    "typescript": "^4.1.3",
    "@types/jest": "^26.0.20",
    "jest": "^26.6.3",
    "ts-jest": "^26.4.4"
  }
}

(Node.js version: v14.2.0)

[ahnpnl]

I think in this case, TypeScript doesn't recognize your custom typing. Maybe you can try to put the typing in a d.ts and add that d.ts to tsconfig files

[mugifly]

Thanks for your reply!
I added a typings with the name global.d.ts, and it was loaded automatically.
In fact, I also tried adding ***.d.ts before posting this question, but it didn't work well...

[mugifly]

Here is the minimum code that worked:

src/index.spec.ts:

import "./matcher";

test("foo", async () => {
  expect("foo").toBeFoo();
});

src/global.d.ts:

declare namespace jest {
  interface Matchers<R> {
    toBeFoo(): R;
  }
}

src/matcher.ts:

import { expect } from "@jest/globals";

expect.extend({
  toBeFoo(received: string) {
    if (received == "foo") {
      return {
        message: () => "OK",
        pass: true,
      };
    } else {
      return {
        message: () => "NG",
        pass: false,
      };
    }
  },
});

package.json:

{
  "name": "tmp",
  "version": "1.0.0",
  "description": "",
  "scripts": {
    "test": "jest"
  },
  "jest": {
    "preset": "ts-jest"
  },
  "dependencies": {},
  "devDependencies": {
    "typescript": "^4.1.3",
    "@types/jest": "^26.0.20",
    "jest": "^26.6.3",
    "ts-jest": "^26.4.4"
  }
}