feat: added tests 82% coverage

Author: XavierCruz5106

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

@@ -45,4 +45,8 @@ public double getSalary() {
   public void setSalary(double salary) {
     this.salary = salary;
   }
+
+  public String getDetails(){
+    return "ID: " + getId() + ", Name: " + getName() + ", Department: " + getDepartment() + ", Salary: " + getSalary();
+  }
 }

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

@@ -1,7 +1,7 @@
 package com.codedifferently.lesson15;
 
 import static org.assertj.core.api.Assertions.assertThat;
-
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import org.junit.jupiter.api.Test;
 
 class Lesson15Test {
@@ -16,4 +16,68 @@ public void testGetGreeting() {
     // Act
     Lesson15.main(null);
   }
+
+  @Test
+  public void employeeManagerAddEmployee(){
+    Employee employee = new Employee(0, null, null, 0);
+    EmployeeManager manager = new EmployeeManager();
+    manager.addEmployee(employee);
+
+    assertEquals(employee, manager.getEmployee(0));
+  }
+
+  @Test
+  public void employeeManagerRemoveEmployee(){
+    Employee employee = new Employee(0, null, null, 0);
+    EmployeeManager manager = new EmployeeManager();
+    manager.addEmployee(employee);
+
+    manager.removeEmployee(0);
+
+    assertEquals(0, manager.getEmployeeCount());
+  }
+
+
+  @Test
+  public void employeeManagerUpdateEmployee(){
+    Employee employee = new Employee(0, null, null, 0);
+    Employee employee2 = new Employee(0, "test", "dept", 0);
+    EmployeeManager manager = new EmployeeManager();
+    manager.addEmployee(employee);
+
+    manager.updateEmployee(employee2);
+
+    assertEquals("ID: 0, Name: test, Department: dept, Salary: 0.0", manager.getEmployee(0).getDetails());
+
+  }
+
+
+  @Test
+  public void getEmployeeDepartment(){
+    Employee employee = new Employee(0, null, "fryCook", 0);
+
+    assertEquals("fryCook", employee.getDepartment());
+  }
+
+  @Test
+  public void getEmployeeSalary(){
+    Employee employee = new Employee(0, null, "fryCook", 999_999);
+
+    assertEquals(999_999, employee.getSalary());
+
+  }
+
+  @Test
+  public void getEmployeeName(){
+    Employee employee = new Employee(0, "James Bartholomew the III", "fryCook", 999_999);
+    assertEquals("James Bartholomew the III", employee.getName());
+
+  }
+
+
+  @Test
+  public void getEmployeeDetails(){
+    Employee employee = new Employee(0, "James Bartholomew the III", "fryCook", 999_999);
+    assertEquals("ID: 0, Name: James Bartholomew the III, Department: fryCook, Salary: 999999.0", employee.getDetails());
+  }
 }