Add semantics to StudentRegistrar test

Author: OctaviPascual

src/mooc/test/tv/codely/mooc/students/StudentsModuleUnitTestCase.java

@@ -0,0 +1,23 @@
+package tv.codely.mooc.students;
+
+import org.junit.jupiter.api.BeforeEach;
+import tv.codely.mooc.students.domain.Student;
+import tv.codely.mooc.students.domain.StudentRepository;
+import tv.codely.shared.infrastructure.UnitTestCase;
+
+import static org.mockito.Mockito.*;
+
+public abstract class StudentsModuleUnitTestCase extends UnitTestCase {
+    protected StudentRepository repository;
+
+    @BeforeEach
+    protected void setUp() {
+        super.setUp();
+
+        repository = mock(StudentRepository.class);
+    }
+
+    public void shouldHaveSaved(Student student) {
+        verify(repository, atLeastOnce()).register(student);
+    }
+}

src/mooc/test/tv/codely/mooc/students/application/register/StudentRegistrarTestShould.java

@@ -1,23 +1,28 @@
 package tv.codely.mooc.students.application.register;
 
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import tv.codely.mooc.students.StudentsModuleUnitTestCase;
 import tv.codely.mooc.students.domain.Student;
 import tv.codely.mooc.students.domain.StudentMother;
-import tv.codely.mooc.students.domain.StudentRepository;
 
-import static org.mockito.Mockito.*;
+final class StudentRegistrarTestShould extends StudentsModuleUnitTestCase {
+    StudentRegistrar registrar;
+
+    @BeforeEach
+    protected void setUp() {
+        super.setUp();
+
+        registrar = new StudentRegistrar(repository);
+    }
 
-final class StudentRegistrarTestShould {
     @Test
     void register_a_valid_student() {
-        StudentRepository repository = mock(StudentRepository.class);
-        StudentRegistrar  registrar  = new StudentRegistrar(repository);
-
         RegisterStudentRequest request = RegisterStudentRequestMother.random();
         Student                student = StudentMother.fromRequest(request);
 
         registrar.register(request);
 
-        verify(repository, atLeastOnce()).register(student);
+        shouldHaveSaved(student);
     }
 }