Add integration tests for StudentService

grails/src/integration-test/groovy/com/baeldung/grails/StudentIntegrationSpec.groovy

@@ -0,0 +1,67 @@
+package com.baeldung.grails
+
+import grails.testing.mixin.integration.Integration
+import grails.gorm.transactions.Rollback
+import spock.lang.Specification
+import org.hibernate.SessionFactory
+
+@Integration
+@Rollback
+class StudentIntegrationSpec extends Specification {
+
+    StudentService studentService
+    SessionFactory sessionFactory
+
+    private Long setupData() {
+        new Student(firstName: 'John',lastName: 'Doe').save(flush: true, failOnError: true)
+        new Student(firstName: 'Max',lastName: 'Foo').save(flush: true, failOnError: true)
+        Student student = new Student(firstName: 'Alex',lastName: 'Bar').save(flush: true, failOnError: true)
+        student.id
+    }
+
+    void "test get"() {
+        Long id = setupData()
+
+        expect:
+        Student student = studentService.get(id)
+        student.firstName == 'Alex'
+        student.lastName == 'Bar'
+    }
+
+    void "test list"() {
+        setupData()
+
+        when:
+        List<Student> studentList = studentService.list()
+
+        then:
+        studentList.size() == 3
+        studentList[0].lastName == 'Doe'
+        studentList[1].lastName == 'Foo'
+        studentList[2].lastName == 'Bar'
+    }
+
+
+    void "test delete"() {
+        Long id = setupData()
+
+        expect:
+        studentService.list().size() == 3
+
+        when:
+        studentService.delete(id)
+        sessionFactory.currentSession.flush()
+
+        then:
+        studentService.list().size() == 2
+    }
+
+    void "test save"() {
+        when:
+        Student student = new Student(firstName: 'John',lastName: 'Doe')
+        studentService.save(student)
+
+        then:
+        student.id != null
+    }
+}