jest-extended-snapshot: Property 'toVerifyAllCombinations' does not exist on type 'JestMatchersShape'

Question

I am trying to write TypeScript for the first time in my life, and I want to use a testing library that can do snapshot testing, with combinations of parameters.

I have already tried jest + jest-extended-snapshot.

Code:

function myFunction(aNumber, aString) {
  if (aNumber > 0) {
    return `${aString} #${aNumber}`;
  }

  if (aString === "foo") {
    return `${aNumber} bar`;
  }

  return "This is twisted…";
}

it("should continue working as before", () => {
  expect(myFunction).toVerifyAllCombinations([1, -1], ["random", "foo"]);
});

Actual output:

> [email protected] test
> jest

 FAIL  test/gilded-rose.spec.ts
  ● Test suite failed to run

    test/gilded-rose.spec.ts:20:33 - error TS2339: Property 'toVerifyAllCombinations' does not exist on type 'JestMatchersShape<Matchers<void, () => string>, Matchers<Promise<void>, () => string>>'.

    20         expect(doUpdateQuality).toVerifyAllCombinations(
                                       ~~~~~~~~~~~~~~~~~~~~~~~

Expected output:

// Jest Snapshot v1, (redacted URL)

exports[`should continue working as before 1`] = `
Object {
  "-1,foo": "-1 bar",
  "-1,random": "This is twisted…",
  "1,foo": "foo #1",
  "1,random": "random #1",
}
`;

If jest&jest-extended-snapshot are not suitable, what should I use instead?

I found a workaround, which I know is the wrong way to fix it, but it does work for me.

I added a file jest.d.ts:

declare global {
    namespace jest {
        interface Matchers<R> {
            toVerifyAllCombinations(expected: string[], [], []): R
        }
    }
}

export {};

This is not maintainable. What is the proper way to tell jest that it needs to add toVerifyAllCombinations to its matchers?