Test: added testAssignGrade

src/test/java/org/example/StudentTest.java

@@ -87,6 +87,25 @@ class StudentTest {
 
     }
 
+    @Test
+    void testAssignGrade() {
+
+        Student student = new Student("John Doe", "S1001", "Student");
+        Course course = new Course("Introduction to Java", "C101", 3); // Assuming your Course class has a constructor that accepts name, ID, and credits
+        // Pre-assignment check: Ensure the course is not already graded
+        assertNull(student.getCourseGrades().get(course), "Course should not have a grade assigned before test.");
+
+        // Assign a grade to the course
+        String grade = "A";
+        student.assignGrade(course, grade);
 
+        // Post-assignment check: Ensure the grade is correctly assigned
+        assertEquals(grade, student.getCourseGrades().get(course), "Grade assigned to course does not match expected grade.");
+
+        // Optional: Test changing the grade
+        String newGrade = "B";
+        student.assignGrade(course, newGrade);
+        assertEquals(newGrade, student.getCourseGrades().get(course), "Grade update for course does not match expected new grade.");
+    }
 
 }