Added StudentTest.java file and added test for writeToFile Method for Student class

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

@@ -0,0 +1,28 @@
+package org.example;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.*;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+class StudentTest {
+
+    @org.junit.jupiter.api.Test
+    void writeToFile() throws IOException {
+        Student student = new Student("Sebastian", "S1001", "Student") ;
+
+        String filename = "testStudentData.txt";
+
+        student.writeToFile(student, filename);
+
+        Path path = Path.of(filename);
+        String content = Files.readString(path);
+        assertEquals("Sebastian\nS1001\nStudent", content);
+
+        Files.delete(path);
+
+    }
+}