tests: add tests for edge cases

Author: CrodiYa

src/test/java/com/thealgorithms/others/IterativeFloodFillTest.java

@@ -1,10 +1,10 @@
 package com.thealgorithms.others;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
+import org.junit.jupiter.api.Test;
+
 class IterativeFloodFillTest {
 
     @Test
@@ -25,6 +25,15 @@ void testForSingleElementImage() {
         assertArrayEquals(expected, image);
     }
 
+    @Test
+    void testForEmptyRow() {
+        int[][] image = {{}};
+        int[][] expected = {{}};
+
+        IterativeFloodFill.floodFill(image, 4, 5, 3, 2);
+        assertArrayEquals(expected, image);
+    }
+
     @Test
     void testForImageOne() {
         int[][] image = {
@@ -111,4 +120,45 @@ void testForBigImage() {
 
         assertDoesNotThrow(() -> IterativeFloodFill.floodFill(image, 0, 0, 1, 0));
     }
+
+    @Test
+    void testForBelowZeroX() {
+        int[][] image = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        int[][] expected = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        IterativeFloodFill.floodFill(image, -1, 1, 1, 0);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForBelowZeroY() {
+        int[][] image = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        int[][] expected = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        IterativeFloodFill.floodFill(image, 1, -1, 1, 0);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForAboveBoundaryX() {
+        int[][] image = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        int[][] expected = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        IterativeFloodFill.floodFill(image, 100, 1, 1, 0);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForAboveBoundaryY() {
+        int[][] image = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        int[][] expected = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        IterativeFloodFill.floodFill(image, 1, 100, 1, 0);
+        assertArrayEquals(expected, image);
+    }
+
 }