Added JUnit tests fo BankersAlgorithmn

Author: Vinay8git

src/test/java/com/thealgorithms/operatingsystemconcepts/BankersAlgorithm.java renamed to src/main/java/com/thealgorithms/operatingsystemconcepts/BankersAlgorithm.java

@@ -1,5 +1,6 @@
 package com.thealgorithms.operatingsystemconcepts;
 
+
 import java.util.Arrays;
 import java.util.Scanner;
 

src/test/java/com/thealgorithms/operatingsystemconcepts/BankersAlgorithmTest.java

@@ -0,0 +1,93 @@
+package com.thealgorithms.operatingsystemconcepts;
+
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import java.io.FileOutputStream;
+import java.io.FileDescriptor;
+
+public class BankersAlgorithmTest {
+
+    private BankersAlgorithm bankersAlgorithm;
+
+    @BeforeEach
+    void setUp() {
+        // Example setup with 5 processes and 3 resources
+        bankersAlgorithm = new BankersAlgorithm(5, 3);
+        
+        // Setting up maximum resources
+        bankersAlgorithm.max = new int[][] {
+            {7, 5, 3},
+            {3, 2, 2},
+            {9, 0, 2},
+            {2, 2, 2},
+            {4, 3, 3}
+        };
+        
+        // Setting up allocation resources
+        bankersAlgorithm.allot = new int[][] {
+            {0, 1, 0},
+            {2, 0, 0},
+            {3, 0, 2},
+            {2, 1, 1},
+            {0, 0, 2}
+        };
+        
+        // Setting up available resources
+        bankersAlgorithm.available = new int[]{3, 3, 2};
+        
+        // Calculating need matrix
+        bankersAlgorithm.calculateNeed();
+    }
+
+    @Test
+    void testSystemIsInSafeState() {
+        assertTrue(bankersAlgorithm.isSafe(), "The system should be in a safe state.");
+    }
+
+    @Test
+    void testRequestResourcesSuccessfully() {
+        int[] request = {1, 0, 2};
+        assertDoesNotThrow(() -> bankersAlgorithm.requestResources(0, request), "Request should not throw an exception.");
+    }
+
+    @Test
+    void testRequestExceedsMaximumClaim() {
+        int[] request = {8, 0, 0};
+        assertEquals("Error: Process has exceeded its maximum claim.", 
+                     getOutput(() -> bankersAlgorithm.requestResources(0, request)),
+                     "Expected error message for exceeding maximum claim.");
+    }
+
+    @Test
+    void testRequestExceedsAvailableResources() {
+        int[] request = {1, 0, 3};
+        assertEquals("Process is waiting.", 
+                     getOutput(() -> bankersAlgorithm.requestResources(0, request)),
+                     "Expected message when requesting more resources than available.");
+    }
+
+    @Test
+    void testRequestResultsInUnsafeState() {
+        // Requesting resources that lead to an unsafe state
+        int[] request = {3, 3, 0};
+        assertEquals("Resources allocation leads to unsafe state, request denied.", 
+                     getOutput(() -> bankersAlgorithm.requestResources(1, request)),
+                     "Expected message when allocation leads to unsafe state.");
+    }
+
+    // Helper method to capture console output
+    private String getOutput(Runnable runnable) {
+        // Code to capture System.out output
+        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+        PrintStream originalOut = System.out; // Save original System.out
+        System.setOut(new PrintStream(outContent));
+        
+        runnable.run();
+        
+        System.setOut(originalOut); // Reset System.out
+        return outContent.toString().trim();
+    }
+}