Add tests

__test__/game.test.js

@@ -0,0 +1,97 @@
+const Game = require('../src/game').default
+
+describe('Game', () => {
+  let game, p1, p2
+  beforeEach(() => {
+    p1 = 'Salem'
+    p2 = 'Nate'
+    game = new Game(p1, p2)
+  })
+
+  describe('Game', () => {
+    it('Initializes with two players', async () => {
+      expect(game.p1).toBe('Salem')
+      expect(game.p2).toBe('Nate')
+    })
+
+    it('Initializes with an empty board', async () => {
+      for (let r = 0; r < game.board.length; r++) {
+        for (let c = 0; c < game.board[r].lenght; c++) {
+          expect(game.board[r][c]).toBeUndefined()
+        }
+      }
+    })
+
+    it('Starts the game with a random player', async () => {
+      Math.random = () => 0.4
+      expect(new Game(p1, p2).player).toBe('Salem')
+
+      Math.random = () => 0.6
+      expect(new Game(p1, p2).player).toBe('Nate')
+    })
+  })
+
+  describe('turn', () => {
+    it("Inserts an 'X' into the top center", async () => {
+      game.turn(0, 1)
+      expect(game.board[0][1]).toBe('X')
+    })
+
+    it("Inserts an 'X' into the top left", async () => {
+      game.turn(0)
+      expect(game.board[0][0]).toBe('X')
+    })
+  })
+
+  describe('nextPlayer', () => {
+    it('Sets the current player to be whoever it is not', async () => {
+      Math.random = () => 0.4
+      const game = new Game(p1, p2)
+      expect(game.player).toBe('Salem')
+      game.nextPlayer()
+      expect(game.player).toBe('Nate')
+    })
+  })
+
+  describe('hasWinner', () => {
+    it('Wins if any row is filled', async () => {
+      for (let r = 0; r < game.board.length; r++) {
+        for (let c = 0; c < game.board[r].length; c++) {
+          game.board[r][c] = 'X'
+        }
+        expect(game.hasWinner()).toBe(true)
+
+        for (let c = 0; c < game.board[r].length; c++) {
+          game.board[r][c] = null
+        }
+      }
+    })
+
+    it('Wins if any column is filled', async () => {
+      for (let r = 0; r < game.board.length; r++) {
+        for (let c = 0; c < game.board[r].length; c++) {
+          game.board[c][r] = 'X'
+        }
+        expect(game.hasWinner()).toBe(true)
+
+        for (let c = 0; c < game.board[r].length; c++) {
+          game.board[c][r] = null
+        }
+      }
+    })
+
+    it('Wins if down-left diagonal is filled', async () => {
+      for (let r = 0; r < game.board.length; r++) {
+        game.board[r][r] = 'X'
+      }
+      expect(game.hasWinner()).toBe(true)
+    })
+
+    it('Wins if up-right diagonal is filled', async () => {
+      for (let r = 0; r < game.board.length; r++) {
+        game.board[2 - r][r] = 'X'
+      }
+      expect(game.hasWinner()).toBe(true)
+    })
+  })
+})