gistfile1.txt

/**
 * @format
 */

import 'react-native';
import React from 'react';
import App from '../App';


// initial value: 0,
// matrix: [
//   00   01   02
//  ['x', 'x', 'y'],
//   10   11   12
//  ['y', 'y', 'x'],
//   20   21   22
//  ['x', 'y', 'x'],
// ]
// 'x', 'x', 'x' row 1, 2, 3
// 
// 'x', col 1, 2, 3
// 'x',
// 'x'
// 
// 'x', 1
//    'x',
//       'x'
//       'x', 1
//    'x',
// 'x'
function isRowWin(row) {
  return row[0] === row[1] && row[0] === row[2];
}
function isColWin(matrix) {
  return (
    (matrix[0][0] === matrix[0][1] && matrix[0][0] === matrix[0][2]) ||
    (matrix[0][1] === matrix[1][1] && matrix[0][1] === matrix[1][2]) ||
    (matrix[0][2] === matrix[2][1] && matrix[0][2] === matrix[2][2])
  )
}
function isDiagWin(matrix) {
  return (
    (matrix[0][0] === matrix[1][1] && matrix[0][0] === matrix[2][2]) ||
    (matrix[2][0] === matrix[1][1] && matrix[0][0] === matrix[0][2])
  )
}
function isDraw(matrix) {
  const isNotYetFinished = matrix.some(row => row.some(x => x === 0));
  if (isNotYetFinished) { return false; }
  // row win
  const [r1, r2, r3] = matrix;
  if (isRowWin(r1) || isRowWin(r2) || isRowWin(r3)) {
    return false;
  }
  // col win
  if (isColWin(matrix)) {
    return false;
  }
  // diagnol win 
  if (isDiagWin(matrix)) {
    return false;
  }
  return true;
}

describe('is draw or not', () => {
  it('return false if it is in initial state', () => {
    expect(isDraw([
      [0, 0, 0],
      [0, 0, 0],
      [0, 0, 0],
    ])).toBe(false);
  });
  it('return false if it is not finished yet', () => {
    expect(isDraw([
      ['x', 'x', 'y'],
      ['y', 'y', 'x'],
      ['x', 'y', 0],
    ])).toBe(false);
  });
  it('when it is finished, return true if draw', () => {
    expect(isDraw([
      ['x', 'x', 'y'],
      ['y', 'y', 'x'],
      ['x', 'y', 'x'],
    ])).toBe(true);
  });
  it('when it is finished, return false if it is not draw', () => {
    expect(isDraw([
      ['x', 'x', 'x'],
      ['y', 'y', 'x'],
      ['x', 'y', 'y'],
    ])).toBe(false);
  });
  it('when it is finished, return false if it is not draw', () => {
    expect(isDraw([
      ['x', 'x', 'y'],
      ['x', 'y', 'x'],
      ['x', 'y', 'y'],
    ])).toBe(false);
  });
  it('when it is finished, return false if it is not draw', () => {
    expect(isDraw([
      ['x', 'y', 'y'],
      ['y', 'x', 'y'],
      ['x', 'y', 'x'],
    ])).toBe(false);
  });
});