How to add custom message to Jest expect?

Question

Image following test case:

it(\'valid emails checks\', () => {
  [\'abc@y.com\', \'a@b.nz\'/*, ...*/].map(mail => {
    expect(isValid(mail)).toBe(true);
          


        

Answer 1

You can use try-catch:

try {
    expect(methodThatReturnsBoolean(inputValue)).toBeTruthy();
}
catch (e) {
    throw new Error(`Something went wrong with value ${JSON.stringify(inputValue)}`, e);
}