Implemented filter for subjects (#129)

Written unit tests and e2e tests for the subject service and subject endpoint

server/src/main/java/de/uftos/dto/SubjectRequestDto.java

@@ -3,6 +3,7 @@
 import de.uftos.entities.Subject;
 import jakarta.validation.constraints.NotEmpty;
 import jakarta.validation.constraints.NotNull;
+import java.util.Collections;
 import java.util.List;
 
 /**
@@ -19,6 +20,6 @@ public record SubjectRequestDto(@NotEmpty String name, String color, @NotNull Li
    * @return the new subject entity.
    */
   public Subject map() {
-    return new Subject(this.name, this.color, this.tagIds);
+    return new Subject(this.name, this.color, this.tagIds == null ? Collections.emptyList() : this.tagIds);
   }
 }

server/src/main/java/de/uftos/repositories/database/SubjectRepository.java

@@ -1,12 +1,14 @@
 package de.uftos.repositories.database;
 
 import de.uftos.entities.Subject;
+import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
 import org.springframework.data.repository.ListCrudRepository;
 import org.springframework.data.repository.ListPagingAndSortingRepository;
 
 /**
  * The repository for accessing the subject database table.
  */
 public interface SubjectRepository
-    extends ListPagingAndSortingRepository<Subject, String>, ListCrudRepository<Subject, String> {
+    extends ListPagingAndSortingRepository<Subject, String>, ListCrudRepository<Subject, String>,
+    JpaSpecificationExecutor<Subject> {
 }

server/src/main/java/de/uftos/services/SubjectService.java

@@ -1,12 +1,14 @@
 package de.uftos.services;
 
+import de.uftos.builders.SpecificationBuilder;
 import de.uftos.dto.SubjectRequestDto;
 import de.uftos.entities.Subject;
 import de.uftos.repositories.database.SubjectRepository;
 import java.util.Optional;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
+import org.springframework.data.jpa.domain.Specification;
 import org.springframework.http.HttpStatus;
 import org.springframework.stereotype.Service;
 import org.springframework.web.server.ResponseStatusException;
@@ -32,11 +34,15 @@ public SubjectService(SubjectRepository repository) {
    * Gets a page of entries of the subject table.
    *
    * @param pageable contains the parameters for the page.
-   * @param name the name filter.
+   * @param name     the name filter.
    * @return the page of the entries fitting the parameters.
    */
   public Page<Subject> get(Pageable pageable, Optional<String> name) {
-    return this.repository.findAll(pageable);
+    Specification<Subject> specification = new SpecificationBuilder<Subject>()
+        .optionalOrEquals(name, "name")
+        .build();
+
+    return this.repository.findAll(specification, pageable);
   }
 
   /**

server/src/test/java/de/uftos/e2e/SubjectsTest.java

@@ -0,0 +1,108 @@
+package de.uftos.e2e;
+
+import static io.restassured.RestAssured.given;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.notNullValue;
+
+import io.restassured.http.ContentType;
+import java.util.Collections;
+import java.util.List;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+class SubjectsTest {
+
+  private static final String SUBJECT1_NAME = "Subject 1";
+  private static final String SUBJECT2_NAME = "Subject 2";
+
+  static String subject1Id;
+  static String subject2Id;
+
+  @BeforeAll
+  static void createTestStudents() throws JSONException {
+    subject1Id = given().contentType(ContentType.JSON)
+        .body(generateSubjectJson(SUBJECT1_NAME))
+        .when()
+        .post("/subjects")
+        .then()
+        .statusCode(200)
+        .body("id", notNullValue())
+        .body("name", equalTo(SUBJECT1_NAME))
+        .log().ifValidationFails()
+        .extract()
+        .body().jsonPath().getString("id");
+
+    subject2Id = given().contentType(ContentType.JSON)
+        .body(generateSubjectJson(SUBJECT2_NAME))
+        .when()
+        .post("/subjects")
+        .then()
+        .statusCode(200)
+        .body("id", notNullValue())
+        .body("name", equalTo(SUBJECT2_NAME))
+        .log().ifValidationFails()
+        .extract()
+        .body().jsonPath().getString("id");
+  }
+
+  @AfterAll
+  static void deleteCreatedStudents() {
+    given().contentType(ContentType.JSON)
+        .when()
+        .delete("/subjects/{id}", subject1Id)
+        .then()
+        .statusCode(200);
+
+    given().contentType(ContentType.JSON)
+        .when()
+        .delete("/subjects/{id}", subject2Id)
+        .then()
+        .statusCode(200);
+  }
+
+  private static String generateSubjectJson(String name)
+      throws JSONException {
+    return new JSONObject()
+        .put("name", name)
+        .put("tags", Collections.emptyList())
+        .toString();
+  }
+
+  private static String generatePageJson(int page, int size, List<String> sort)
+      throws JSONException {
+    return new JSONObject()
+        .put("page", page)
+        .put("size", size)
+        .put("sort", sort)
+        .toString();
+  }
+
+  @Test
+  void getAllSubjects() throws JSONException {
+    given().contentType(ContentType.JSON)
+        .body(generatePageJson(0, 10, Collections.emptyList()))
+        .when()
+        .get("/subjects")
+        .then()
+        .statusCode(200)
+        .body("totalElements", equalTo(2))
+        .log().ifValidationFails();
+  }
+
+  @Test
+  void getSubjectsWithName() throws JSONException {
+    given().contentType(ContentType.JSON)
+        .body(generatePageJson(0, 10, Collections.emptyList()))
+        .param("name", "ct 1")
+        .when()
+        .get("/subjects")
+        .then()
+        .statusCode(200)
+        .body("totalElements", equalTo(1))
+        .body("content[0].id", equalTo(subject1Id))
+        .log().ifValidationFails();
+  }
+}

server/src/test/java/de/uftos/services/SubjectServiceTests.java

@@ -0,0 +1,60 @@
+package de.uftos.services;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.mockito.Mockito.when;
+
+import de.uftos.entities.Subject;
+import de.uftos.entities.Tag;
+import de.uftos.repositories.database.SubjectRepository;
+import java.util.List;
+import java.util.Optional;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.mockito.junit.jupiter.MockitoSettings;
+import org.mockito.quality.Strictness;
+
+@ExtendWith(MockitoExtension.class)
+@MockitoSettings(strictness = Strictness.LENIENT)
+public class SubjectServiceTests {
+
+  private static final String TAG_NAME = "test tag";
+  private static final String TAG_ID = "456";
+  private static final String SUBJECT_ID = "123";
+  private static final String SUBJECT_NAME = "English";
+
+  @Mock
+  private SubjectRepository subjectRepository;
+
+  @InjectMocks
+  private SubjectService subjectService;
+
+  @BeforeEach
+  void setUp() {
+    Tag tag = new Tag();
+    tag.setId(TAG_ID);
+    tag.setName(TAG_NAME);
+
+    Subject subject = new Subject();
+    subject.setId(SUBJECT_ID);
+    subject.setName(SUBJECT_NAME);
+    subject.setTags(List.of(tag));
+
+    when(subjectRepository.findAll()).thenReturn(List.of(subject));
+    when(subjectRepository.findById(SUBJECT_ID)).thenReturn(Optional.of(subject));
+  }
+
+  @Test
+  void lessonsById() {
+    Subject result = subjectService.getById(SUBJECT_ID);
+    assertNotNull(result);
+    assertEquals(SUBJECT_ID, result.getId());
+    assertFalse(result.getTags().isEmpty());
+    assertEquals(TAG_ID, result.getTags().getFirst().getId());
+  }
+}