chore: updated employeemanagertest

Author: haldanek

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

@@ -45,4 +45,9 @@ public double getSalary() {
   public void setSalary(double salary) {
     this.salary = salary;
   }
+
+  public boolean containsKey(Object id2) {
+    // TODO Auto-generated method stub
+    throw new UnsupportedOperationException("Unimplemented method 'containsKey'");
+  }
 }

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

@@ -1,11 +1,12 @@
 package com.codedifferently.lesson15;
 
+import static org.assertj.core.api.Assertions.*;
 import static org.junit.jupiter.api.Assertions.*;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-class Lesson15Test {
+class EmployeeManagerTest {
 
   private EmployeeManager manager;
   private Employee emp;
@@ -49,4 +50,24 @@ public void testUpdateEmployee() {
         manager.getEmployee(1),
         "Updated employee details should match the new information.");
   }
+
+  @Test
+  public void testRemoveEmployee() {
+    // Arrange
+    manager.addEmployee(emp);
+    // Act
+    manager.removeEmployee(1);
+    Employee removedEmployee = manager.getEmployee(1);
+    // Assert
+    assertEquals(0, manager.getEmployeeCount(), "Employee count should be 0.");
+    assertNull(removedEmployee, "Employee should be removed from system.");
+  }
+
+  @Test
+  public void testAssertEmployeeInCollection() throws Exception {
+    // Act
+    assertThatThrownBy(() -> manager.getEmployee(1))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("Employee does not in collection with id 1");
+  }
 }