Created Chess class with convertInput method with test

src/main/java/Game/Chess.java

@@ -0,0 +1,53 @@
+package Game;
+
+import Game.ChessObj.ChessBoard;
+
+public class Chess extends Game {
+
+    ChessBoard chessBoard;
+
+    public Chess() {
+        init();
+    }
+
+    private void init() {
+        chessBoard = new ChessBoard();
+        outputBuffer.addAll(chessBoard.getOutputBoard());
+    }
+
+    @Override
+    public void update(String input) {
+
+    }
+
+    //int[0] = x, int[1] = y;
+    public int[] convertInput(String input) {
+        int[] temp = new int[2];
+
+        //input is not 2 chars big
+        if (input.length() != 2)
+            return null;
+        char[] symbols = input.toCharArray();
+        int counterDigit = 0;
+        int counterChar = 0;
+        //input contains one number and one char
+        for (char x : symbols) {
+            if (Character.isDigit(x)) {
+                counterDigit++;
+                temp[1] = Character.getNumericValue(x) - 1;
+            }
+            if (Character.isAlphabetic(x)) {
+                counterChar++;
+                temp[0] = x;
+            }
+        }
+        if (counterChar != 1 || counterDigit != 1)
+            return null;
+
+        temp[0] = Character.toLowerCase(temp[0]) - 97;
+        if (!chessBoard.isCellInBoard(temp[0], temp[1]))
+            return null;
+        else
+            return temp;
+    }
+}

src/test/java/Game/ChessTest.java

@@ -0,0 +1,43 @@
+package Game;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+class ChessTest {
+
+    Chess chess;
+
+    @BeforeEach
+    void setUp() {
+        chess = new Chess();
+    }
+
+    @AfterEach
+    void tearDown() {
+    }
+
+    @Test
+    void convertInput() {
+        int[] test1 = {0, 0};
+        int[] test2 = {7, 7};
+        int[] test3 = {6, 2};
+
+        assertNull(chess.convertInput("0g2"));
+        assertNull(chess.convertInput("25"));
+        assertNull(chess.convertInput("bg"));
+        assertNull(chess.convertInput("9b"));
+        assertNull(chess.convertInput("2i"));
+
+        assertArrayEquals(chess.convertInput("1a"), test1);
+        assertArrayEquals((chess.convertInput("a1")), test1);
+        assertArrayEquals((chess.convertInput("8h")), test2);
+        assertArrayEquals((chess.convertInput("h8")), test2);
+
+        assertArrayEquals((chess.convertInput("3G")), test3);
+        assertArrayEquals((chess.convertInput("G3")), test3);
+    }
+}