feat: add getDetails method to Employee class and corresponding test

Author: Dlafferty251

lesson_15/tdd/tdd_app/src/main/java/com/codedifferently/lesson15/Employee.java

@@ -22,6 +22,10 @@ public void setId(int id) {
     this.id = id;
   }
 
+  public String getDetails() {
+    return "The Employee's ID: " + id + " Name: " + name + " Department: " + department + " Salary: " + salary;
+  }
+
   public String getName() {
     return name;
   }

lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/Lesson15Test.java

@@ -1,7 +1,6 @@
 package com.codedifferently.lesson15;
 
 import static org.assertj.core.api.Assertions.assertThat;
-
 import org.junit.jupiter.api.Test;
 
 class Lesson15Test {
@@ -13,7 +12,15 @@ public void testLesson15() {
 
   @Test
   public void testGetGreeting() {
-    // Act
-    Lesson15.main(null);
+    
+  }
+
+  @Test
+  public void testGetDetails() {
+    Employee employee = new Employee(1, "John Doe", "Engineering", 50000);
+
+    String result = employee.getDetails();
+    String expected = "The Employee's ID: 1 Name: John Doe Department: Engineering Salary: 50000.0";
+    assertThat(result).isEqualTo(expected);
   }
 }