import { parseKeyValuePairs } from './parseKeyValuePairs';

interface TestCase {
  description: string;
  input: string[];
  result: Record<string, string>;
  tests: TestFunction[];
}

type TestFunction = (t: TestCase) => void;

function checkResult(t: TestCase) {
  it('should return the expected result', () => {
    const result = parseKeyValuePairs(t.input);

    expect(result).toEqual(t.result);
  });
}

function shouldNotThrow(t: TestCase) {
  it('should not throw an error', () => {
    let err: Error | undefined;
    try {
      parseKeyValuePairs(t.input);
    } catch (e) {
      err = e as Error;
    }

    expect(err).toBeUndefined();
  });
}

const testCases: TestCase[] = [
  {
    description: 'when the input is a single key=value item',
    input: ['alpha=beta'],
    result: {
      alpha: 'beta',
    },
    tests: [checkResult, shouldNotThrow],
  },
  {
    description:
      'when the input is multiple key=value items in the same string',
    input: ['alpha=beta,gamma=delta'],
    result: {
      alpha: 'beta',
      gamma: 'delta',
    },
    tests: [checkResult, shouldNotThrow],
  },
  {
    description: 'when the input is a single JSON style item',
    input: ['{"alpha":"beta"}'],
    result: {
      alpha: 'beta',
    },
    tests: [checkResult, shouldNotThrow],
  },
  {
    description: 'when the input is a JSON object with multiple items',
    input: ['{"alpha":"beta","gamma":"delta"}'],
    result: {
      alpha: 'beta',
      gamma: 'delta',
    },
    tests: [checkResult, shouldNotThrow],
  },
  {
    description: 'when the input is multiple JSON items',
    input: ['{"alpha":"beta"}', '{"gamma":"delta"}'],
    result: {
      alpha: 'beta',
      gamma: 'delta',
    },
    tests: [checkResult, shouldNotThrow],
  },
  {
    description: 'when the input is a mix of JSON items and key-value pairs',
    input: ['{"alpha":"beta"}', 'gamma=delta'],
    result: {
      alpha: 'beta',
      gamma: 'delta',
    },
    tests: [checkResult, shouldNotThrow],
  },
  {
    description: 'when the input is an empty string',
    input: [''],
    result: {},
    tests: [checkResult, shouldNotThrow],
  },
  {
    description: 'when the input is invalid JSON',
    input: ['{"alpha":"beta'],
    result: {},
    tests: [checkResult, shouldNotThrow],
  },
  {
    description: 'when the input is invalid comma-separated key=value pairs',
    input: ['alpha,beta,=gamma,delta='],
    result: {},
    tests: [checkResult, shouldNotThrow],
  },
];

describe('parseKeyValuePairs', () => {
  for (const t of testCases) {
    describe(t.description, () => {
      for (const test of t.tests) {
        test(t);
      }
    });
  }
});