Added expect.satisfies(predicate) matcher

[johnw42]

Summary

This PR adds a new matcher, expect.satisfies(predicate), similar to toSatisfy matcher from the jest-extended package but implemented as an asymmetric matcher for more flexibility. It is useful for composing with other expectation functions to test for arbitrary conditions without going outside the expect(subject).toVerb(object) pattern.

For example, consider the example code for expect.objectContaining(object), but modified to accept only even numbers:

test('onPress gets called with the right thing', () => {
  const onPress = jest.fn();
  simulatePresses(onPress);
  const isEven = (n) => n % 2 === 0;
  expect(onPress).toHaveBeenCalledWith(
    expect.objectContaining({
      x: expect.satisfies(isEven), // Prints as "Satisfies isEven"
      y: expect.satisfies(isEven),
    }),
  );
});

Without expect.satisfies, the expect call has to be totally rewritten in a way that's harder to read and produces much less helpful error messages:

let isOk = false;
for (const [arg] of onPress.mock.calls) {
  if (isEven(arg.x) && isEven(arg.y)) {
    isOk = true;
    break;
  }
}
expect(isOk).toBe(true);

For further motivation, consider the Truly matcher from Gtest, which is used in numerous places in Chromium.

Test plan

This PR includes full unit tests for the new functionality.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: johnw42 / name: John Williams (94def65, 3153cf2, 19f528d, e194155)

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