Table tests with Jest (including exceptions)

testing.helper.ts

// If you ever so fancy, you might want to check: unzip.dev

export const tableTest = (
  test: jest.It,
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  cases: any[][],
  testFn: CallableFunction
) => {
  test.each(cases)(`${testFn.name}(%s) should be %s`, async (input, output) => {
    const asyncFn = testFn.constructor.name == 'AsyncFunction';
    const inputIsArr = Array.isArray(input) && input.length > 0;

    if (output instanceof Error) {
      if (asyncFn) {
        await expect(() =>
          inputIsArr ? testFn(...input) : testFn(input)
        ).rejects.toThrow((output as Error).message);
      } else {
        expect(() => {
          inputIsArr ? testFn(...input) : testFn(input);
        }).toThrow((output as Error).message);
      }
    } else if (output instanceof Function) {
      const result = inputIsArr ? testFn(...input) : testFn(input);
      expect(output(result)).toBeTruthy();
    } else {
      if (asyncFn) {
        const result = inputIsArr
          ? await testFn(...input)
          : await testFn(input);
        expect(result).toEqual(output);
      } else {
        const result = inputIsArr ? testFn(...input) : testFn(input);
        expect(result).toEqual(output);
      }
    }
  });
};


// Example
// You can use a value, an Error or a function as the output (2nd item in the cases array).
describe('domainToBaseURL', () => {
  const cases = [
    ['example.com', 'https://example.com/'],
    ['asd.example.com', 'https://asd.example.com/'],
    ['asd.example.com', 'https://asd.example.com/'],
    ['', Error('domain is empty')],
    ['https://test.com?ref', (result) => result.includes('ref')],
    [['param1', 'param2', 'param3'], 'result']
  ];
  tableTest(test, cases, domainToBaseURL);
});