update&test[utils]: Add positive and negative JUnit tests to Paramete…

…rValidator class, ensuring full test coverage

src/main/java/edu/group5/app/utils/ParameterValidator.java

@@ -29,7 +29,6 @@ public static final void stringChecker(String stringArg, String variableName) th
    * @throws IllegalArgumentException if the integer is null or not a positive integer
    */
   public static final void intChecker(int intArg, String variableName) throws IllegalArgumentException {
-    nullCheck(intArg, variableName);
     if (intArg <= 0) {
       throw new IllegalArgumentException(String.format("%s must be a positive integer", variableName));
     }

src/test/java/edu/group5/app/utils/ParameterValidatorTest.java

@@ -0,0 +1,63 @@
+package edu.group5.app.utils;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class ParameterValidatorTest {
+
+  @Test
+  void testValidatorDoesNotThrowWithValidParameters() {
+    assertDoesNotThrow(() -> ParameterValidator.stringChecker("valid", "validString"));
+    assertDoesNotThrow(() -> ParameterValidator.intChecker(1, "positiveInt"));
+    assertDoesNotThrow(() -> ParameterValidator.objectChecker(new Object(), "validObject"));
+    assertDoesNotThrow(() -> ParameterValidator.bigDecimalChecker(java.math.BigDecimal.valueOf(1), "positiveBigDecimal"));
+  }
+
+  @Test
+  void testValidatorThrowsWithStringChecker() {
+    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {
+      ParameterValidator.stringChecker(null, "nullString");
+    });
+    IllegalArgumentException exception2 = assertThrows(IllegalArgumentException.class, () -> {
+      ParameterValidator.stringChecker("", "emptyString");
+    });
+    IllegalArgumentException exception3 = assertThrows(IllegalArgumentException.class, () -> {
+      ParameterValidator.stringChecker("   ", "blankString");
+    });
+    assertEquals("nullString can't be null", exception.getMessage());
+    assertEquals("emptyString can't be blank", exception2.getMessage());
+    assertEquals("blankString can't be blank", exception3.getMessage());
+  }
+
+  @Test
+  void testValidatorThrowsWithIntChecker() {
+    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {
+      ParameterValidator.intChecker(-1, "negativeInt");
+    });
+    assertEquals("negativeInt must be a positive integer", exception.getMessage());
+  }
+
+  @Test
+  void testValidatorThrowsWithObjectChecker() {
+    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {
+      ParameterValidator.objectChecker(null, "nullObject");
+    });
+    assertEquals("nullObject can't be null", exception.getMessage());
+  }
+
+  @Test
+  void testValidatorThrowsWithBigDecimalChecker() {
+    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {
+      ParameterValidator.bigDecimalChecker(null, "nullBigDecimal");
+    });
+    IllegalArgumentException exception2 = assertThrows(IllegalArgumentException.class, () -> {
+      ParameterValidator.bigDecimalChecker(java.math.BigDecimal.valueOf(-1), "negativeBigDecimal");
+    });
+    IllegalArgumentException exception3 = assertThrows(IllegalArgumentException.class, () -> {
+    ParameterValidator.bigDecimalChecker(java.math.BigDecimal.ZERO, "zeroBigDecimal");
+    });
+    assertEquals("nullBigDecimal can't be null", exception.getMessage());
+    assertEquals("negativeBigDecimal must be larger than 0", exception2.getMessage());
+    assertEquals("zeroBigDecimal must be larger than 0", exception3.getMessage());
+  }
+}