tictactoe: added method countCharsInCol

src/main/java/de/tims/tictactoe/ai/AIHard.java

@@ -59,10 +59,15 @@ public class AIHard implements TicTacToeAI {
 	public int countCharsInRow(int index, char charToCount) {
 		int count = 0;
 		char[][] board = gl.getBoard();
+		
 		for (int i = 0; i < BOARD_SIZE; i++) {
 			count += (board[index][i] == charToCount) ? 1 : 0;
 		}
 		
 		return count;
 	}
+	
+	public int countCharsInCol(int index, char charToCount) {
+		return 0;
+	}
 }

src/test/java/de/tims/tictactoe/ai/AIHardTest.java

@@ -85,5 +85,22 @@ class AIHardTest {
 						new char[][] { {'-', '-', '-'}, {'o', 'o', '-'}, {'-', '-', '-'} },
 						1, 'o', 2));
 	}
+	
+	@ParameterizedTest
+	@MethodSource("testCasesForCountCharsInCol")
+	void countCharsInColTest(String testName, char[][] board, int rowNum, char charToCount, int expectedResult) {
+		doReturn(board).when(gl).getBoard();
+		
+		AIHard ai = new AIHard(gl);
+		int realResult = ai.countCharsInCol(rowNum, charToCount);
+		
+		assertThat(realResult).describedAs(testName).isEqualTo(expectedResult);
+	}
+	
+	private static Stream<Arguments> testCasesForCountCharsInCol() {
+		return Stream.of(Arguments.of("EmptyFieldReturns0", 
+						new char[][] { {'-', '-', '-'}, {'-', '-', '-'}, {'-', '-', '-'} },
+						0, 'o', 0));
+	}
 
 }