feature: implement toHaveDisplayValue Jest matcher

[mdjastrzebski]

Describe the Feature

toHaveDisplayValue is a Jest DOM matcher that asserts the value visible to the user in text inputs.

Adapting it to our case it would assert the value in TextInput host elements, to match given value.

Possible Implementations

Proposed API:

export function toHaveDisplayValue(
  this: jest.MatcherContext,
  element: ReactTestInstance,
  valueToMatch: TextMatch,
  options?: TextMatchOptions
)

The matcher should:

1. Validate that it is invoked on host TextInput element
2. Get the current value as props.value ?? props.defaultValue
3. Compare it with passed valueToMatch.

Each matcher should have a fairly comprehensive test suite.

Links

• toHaveDisplayValue matcher code from Jest DOM: https://github.com/testing-library/jest-dom/blob/main/src/to-have-display-value.js

Related Issues

#1454

[mdjastrzebski]

🎉 Release in version: v12.4.0