Simplify create and update merge request (#464) (#473).

src/main/java/org/gitlab4j/api/MergeRequestApi.java

@@ -14,6 +14,7 @@ import org.gitlab4j.api.models.Commit;
 import org.gitlab4j.api.models.Issue;
 import org.gitlab4j.api.models.MergeRequest;
 import org.gitlab4j.api.models.MergeRequestFilter;
+import org.gitlab4j.api.models.MergeRequestParams;
 import org.gitlab4j.api.models.Participant;
 
 /**
@@ -337,7 +338,24 @@ public class MergeRequestApi extends AbstractApi {
     }
 
     /**
-     * Creates a merge request and optionally assigns a reviewer to it.
+     * Creates a merge request.
+     *
+     * <pre><code>GitLab Endpoint: POST /projects/:id/merge_requests</code></pre>
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @param params a MergeRequestParams instance holding the info to create the merge request
+     * @return the created MergeRequest instance
+     * @throws GitLabApiException if any exception occurs
+     * @since GitLab Starter 8.17, GitLab CE 11.0.
+     */
+    public MergeRequest createMergeRequest(Object projectIdOrPath, MergeRequestParams params) throws GitLabApiException {
+	GitLabApiForm form = params.getForm(true);
+        Response response = post(Response.Status.CREATED, form, "projects", getProjectIdOrPath(projectIdOrPath), "merge_requests");
+        return (response.readEntity(MergeRequest.class));
+    }
+
+    /**
+     * Creates a merge request.
      *
      * <pre><code>GitLab Endpoint: POST /projects/:id/merge_requests</code></pre>
      *
@@ -359,24 +377,23 @@ public class MergeRequestApi extends AbstractApi {
     public MergeRequest createMergeRequest(Object projectIdOrPath, String sourceBranch, String targetBranch, String title, String description, Integer assigneeId,
             Integer targetProjectId, String[] labels, Integer milestoneId, Boolean removeSourceBranch, Boolean squash) throws GitLabApiException {
 
-        Form formData = new Form();
-        addFormParam(formData, "source_branch", sourceBranch, true);
-        addFormParam(formData, "target_branch", targetBranch, true);
-        addFormParam(formData, "title", title, true);
-        addFormParam(formData, "description", description, false);
-        addFormParam(formData, "assignee_id", assigneeId, false);
-        addFormParam(formData, "target_project_id", targetProjectId, false);
-        addFormParam(formData, "labels", labels == null ? null : String.join(",", labels), false);
-        addFormParam(formData, "milestone_id", milestoneId, false);
-        addFormParam(formData, "remove_source_branch", removeSourceBranch, false);
-        addFormParam(formData, "squash", squash, false);
-
-        Response response = post(Response.Status.CREATED, formData, "projects", getProjectIdOrPath(projectIdOrPath), "merge_requests");
-        return (response.readEntity(MergeRequest.class));
+        MergeRequestParams params = new MergeRequestParams()
+            .withSourceBranch(sourceBranch)
+            .withTargetBranch(targetBranch)
+            .withTitle(title)
+            .withDescription(description)
+            .withAssigneeId(assigneeId)
+            .withTargetProjectId(targetProjectId)
+            .withLabels(labels)
+            .withMilestoneId(milestoneId)
+            .withRemoveSourceBranch(removeSourceBranch)
+            .withSquash(squash);
+
+        return(createMergeRequest(projectIdOrPath, params));
     }
 
     /**
-     * Creates a merge request and optionally assigns a reviewer to it.
+     * Creates a merge request.
      *
      * <pre><code>GitLab Endpoint: POST /projects/:id/merge_requests</code></pre>
      *
@@ -395,7 +412,19 @@ public class MergeRequestApi extends AbstractApi {
      */
     public MergeRequest createMergeRequest(Object projectIdOrPath, String sourceBranch, String targetBranch, String title, String description, Integer assigneeId,
                 Integer targetProjectId, String[] labels, Integer milestoneId, Boolean removeSourceBranch) throws GitLabApiException {
-       return createMergeRequest(projectIdOrPath, sourceBranch, targetBranch, title, description, assigneeId, targetProjectId, labels, milestoneId, removeSourceBranch, null);
+
+	MergeRequestParams params = new MergeRequestParams()
+	    .withSourceBranch(sourceBranch)
+	    .withTargetBranch(targetBranch)
+	    .withTitle(title)
+	    .withDescription(description)
+	    .withAssigneeId(assigneeId)
+	    .withTargetProjectId(targetProjectId)
+	    .withLabels(labels)
+	    .withMilestoneId(milestoneId)
+	    .withRemoveSourceBranch(removeSourceBranch);
+
+	return(createMergeRequest(projectIdOrPath, params));
     }
 
     /**
@@ -414,54 +443,33 @@ public class MergeRequestApi extends AbstractApi {
      */
     public MergeRequest createMergeRequest(Object projectIdOrPath, String sourceBranch, String targetBranch, String title, String description, Integer assigneeId)
             throws GitLabApiException {
-        return createMergeRequest(projectIdOrPath, sourceBranch, targetBranch, title, description, assigneeId, null, null, null, null);
+
+	MergeRequestParams params = new MergeRequestParams()
+	    .withSourceBranch(sourceBranch)
+	    .withTargetBranch(targetBranch)
+	    .withTitle(title)
+	    .withDescription(description)
+	    .withAssigneeId(assigneeId);
+
+	return(createMergeRequest(projectIdOrPath, params));
     }
 
     /**
-     * Updates an existing merge request. You can change branches, title, or even close the MR.
-     *
-     * <p>NOTE: GitLab API V4 uses IID (internal ID), V3 uses ID to identify the merge request.</p>
+     * Updates an existing merge request. You can change branches, title, or even close the merge request.
      *
      * <pre><code>GitLab Endpoint: PUT /projects/:id/merge_requests/:merge_request_iid</code></pre>
      *
      * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid the internal ID of the merge request to update
-     * @param targetBranch the target branch, optional
-     * @param title the title for the merge request
-     * @param assigneeId the Assignee user ID, optional
-     * @param description the description of the merge request, optional
-     * @param stateEvent new state for the merge request, optional
-     * @param labels comma separated list of labels, optional
-     * @param milestoneId the ID of a milestone, optional
-     * @param removeSourceBranch Flag indicating if a merge request should remove the source
-     *                           branch when merging, optional
-     * @param squash Squash commits into a single commit when merging, optional
-     * @param discussionLocked Flag indicating if the merge request's discussion is locked, optional
-     * @param allowCollaboration Allow commits from members who can merge to the target branch,
-     *                           optional
+     * @param params a MergeRequestParams instance holding the info to update the merge request
      * @return the updated merge request
      * @throws GitLabApiException if any exception occurs
      */
-    public MergeRequest updateMergeRequest(Object projectIdOrPath, Integer mergeRequestIid,
-            String targetBranch, String title, Integer assigneeId, String description,
-            StateEvent stateEvent, String labels, Integer milestoneId, Boolean removeSourceBranch,
-            Boolean squash, Boolean discussionLocked, Boolean allowCollaboration)
-            throws GitLabApiException {
-
-        Form formData = new GitLabApiForm()
-                .withParam("target_branch", targetBranch)
-                .withParam("title", title)
-                .withParam("assignee_id", assigneeId)
-                .withParam("description", description)
-                .withParam("state_event", stateEvent)
-                .withParam("labels", labels)
-                .withParam("milestone_id", milestoneId)
-                .withParam("remove_source_branch", removeSourceBranch)
-                .withParam("squash", squash)
-                .withParam("discussion_locked", discussionLocked)
-                .withParam("allow_collaboration", allowCollaboration);
-
-        return updateMergeRequest(projectIdOrPath, mergeRequestIid, formData);
+    public MergeRequest updateMergeRequest(Object projectIdOrPath, Integer mergeRequestIid, MergeRequestParams params) throws GitLabApiException {
+	GitLabApiForm form = params.getForm(false);
+	Response response = put(Response.Status.OK, form.asMap(),
+		"projects", getProjectIdOrPath(projectIdOrPath), "merge_requests", mergeRequestIid);
+	 return (response.readEntity(MergeRequest.class));
     }
 
     /**
@@ -480,68 +488,40 @@ public class MergeRequestApi extends AbstractApi {
      * @param stateEvent new state for the merge request, optional
      * @param labels comma separated list of labels, optional
      * @param milestoneId the ID of a milestone, optional
+     * @param removeSourceBranch Flag indicating if a merge request should remove the source
+     *                           branch when merging, optional
+     * @param squash Squash commits into a single commit when merging, optional
+     * @param discussionLocked Flag indicating if the merge request's discussion is locked, optional
+     * @param allowCollaboration Allow commits from members who can merge to the target branch,
+     *                           optional
      * @return the updated merge request
      * @throws GitLabApiException if any exception occurs
      */
-    @Deprecated
-    public MergeRequest updateMergeRequest(Object projectIdOrPath, Integer mergeRequestIid, String targetBranch,
-            String title, Integer assigneeId, String description, StateEvent stateEvent, String labels,
-            Integer milestoneId) throws GitLabApiException {
-
-        Form formData = new GitLabApiForm()
-        .withParam("target_branch", targetBranch)
-        .withParam("title", title)
-        .withParam("assignee_id", assigneeId)
-        .withParam("description", description)
-        .withParam("state_event", stateEvent)
-        .withParam("labels", labels)
-        .withParam("milestone_id", milestoneId);
-
-        return updateMergeRequest(projectIdOrPath, mergeRequestIid, formData);
-    }
-
-    /**
-     * Updates an existing merge request. You can change branches, title, or even close the MR.
-     *
-     * <p>NOTE: GitLab API V4 uses IID (internal ID), V3 uses ID to identify the merge request.</p>
-     *
-     * <pre><code>GitLab Endpoint: PUT /projects/:id/merge_requests/:merge_request_iid</code></pre>
-     *
-     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
-     * @param mergeRequestIid the internal ID of the merge request to update
-     * @param sourceBranch the source branch
-     * @param targetBranch the target branch
-     * @param title the title for the merge request
-     * @param description the description of the merge request
-     * @param assigneeId the Assignee user ID, optional
-     * @return the updated merge request
-     * @throws GitLabApiException if any exception occurs
-     * @deprecated as of release 4.4.3
-     */
-    @Deprecated
-    public MergeRequest updateMergeRequest(Object projectIdOrPath, Integer mergeRequestIid, String sourceBranch, String targetBranch, String title, String description,
-            Integer assigneeId) throws GitLabApiException {
-
-        Form formData = new Form();
-        addFormParam(formData, "source_branch", sourceBranch, false);
-        addFormParam(formData, "target_branch", targetBranch, false);
-        addFormParam(formData, "title", title, false);
-        addFormParam(formData, "description", description, false);
-        addFormParam(formData, "assignee_id", assigneeId, false);
-
-        return updateMergeRequest(projectIdOrPath, mergeRequestIid, formData);
-    }
-
-    protected MergeRequest updateMergeRequest(Object projectIdOrPath, Integer mergeRequestIid,
-            Form formData) throws GitLabApiException {
-
-        if (mergeRequestIid == null) {
-            throw new RuntimeException("mergeRequestId cannot be null");
-        }
+    public MergeRequest updateMergeRequest(Object projectIdOrPath, Integer mergeRequestIid,
+            String targetBranch, String title, Integer assigneeId, String description,
+            StateEvent stateEvent, String labels, Integer milestoneId, Boolean removeSourceBranch,
+            Boolean squash, Boolean discussionLocked, Boolean allowCollaboration)
+            throws GitLabApiException {
 
-        Response response = put(Response.Status.OK, formData.asMap(), "projects", getProjectIdOrPath(projectIdOrPath),
-                "merge_requests", mergeRequestIid);
-        return (response.readEntity(MergeRequest.class));
+	String[] labelsArray = null;
+	if (labels != null) {
+	    labelsArray = labels.split(",", -1);
+	}
+
+	MergeRequestParams params = new MergeRequestParams()
+	        .withTargetBranch(targetBranch)
+	        .withTitle(title)
+	        .withAssigneeId(assigneeId)
+	        .withDescription(description)
+	        .withStateEvent(stateEvent)
+	        .withLabels(labelsArray)
+	        .withMilestoneId(milestoneId)
+	        .withRemoveSourceBranch(removeSourceBranch)
+	        .withDiscussionLocked(discussionLocked)
+	        .withAllowCollaboration(allowCollaboration)
+	        .withSquash(squash);
+
+        return (updateMergeRequest(projectIdOrPath, mergeRequestIid, params));
     }
 
     /**

src/main/java/org/gitlab4j/api/models/MergeRequestParams.java

+package org.gitlab4j.api.models;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.gitlab4j.api.Constants.StateEvent;
+import org.gitlab4j.api.GitLabApiForm;
+
+/**
+ * This class provides the form parameters for creating and updating merge requests.
+ */
+public class MergeRequestParams {
+
+    private String sourceBranch;
+    private String targetBranch;
+    private String title;
+    private Integer assigneeId;
+    private List<Integer> assigneeIds;
+    private Integer milestoneId;
+    private List<String> labels;
+    private String description;
+    private Integer targetProjectId;
+    private StateEvent stateEvent;
+    private Boolean removeSourceBranch;
+    private Boolean squash;
+    private Boolean discussionLocked;
+    private Boolean allowCollaboration;
+    private Integer approvalsBeforeMerge;
+
+    /**
+     * Set the source branch. This is for merge request creation only.
+     *
+     * @param sourceBranch the sourceBranch to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withSourceBranch(String sourceBranch) {
+	this.sourceBranch = sourceBranch;
+	return (this);
+    }
+
+    /**
+     * Set the target branch.
+     *
+     * @param targetBranch the targetBranch to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withTargetBranch(String targetBranch) {
+	this.targetBranch = targetBranch;
+	return (this);
+    }
+
+    /**
+     * Set the title of the merge request.
+     *
+     * @param title the title to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withTitle(String title) {
+	this.title = title;
+	return (this);
+    }
+
+    /**
+     * Set the assignee user ID.
+     *
+     * @param assigneeId the assigneeId to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withAssigneeId(Integer assigneeId) {
+	this.assigneeId = assigneeId;
+	return (this);
+    }
+
+    /**
+     * The ID of the user(s) to assign the merge request to. Set to 0 or provide
+     * an empty value to unassign all assignees.
+     *
+     * @param assigneeIds the assigneeIds to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withAssigneeIds(List<Integer> assigneeIds) {
+	this.assigneeIds = assigneeIds;
+	return (this);
+    }
+
+    /**
+     * Set the milestone ID field value.
+     *
+     * @param milestoneId the milestoneId to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withMilestoneId(Integer milestoneId) {
+	this.milestoneId = milestoneId;
+	return (this);
+    }
+
+    /**
+     * Set the labels for the merge request.
+     *
+     * @param labels the List of labels to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withLabels(List<String> labels) {
+	this.labels = labels;
+	return (this);
+    }
+
+    /**
+     * Set the labels for the merge request.
+     *
+     * @param labels the array of labels to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withLabels(String[] labels) {
+	this.labels = (labels != null ? Arrays.asList(labels) : null);
+	return (this);
+    }
+
+    /**
+     * Set the description of the merge request. Limited to 1,048,576 characters.
+     *
+     * @param description the description to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withDescription(String description) {
+	this.description = description;
+	return (this);
+    }
+
+    /**
+     * Set the target project ID. This is for merge request creation only.
+     *
+     * @param targetProjectId the targetProjectId to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withTargetProjectId(Integer targetProjectId) {
+	this.targetProjectId = targetProjectId;
+	return (this);
+    }
+
+    /**
+     * New state (close/reopen). This is for merge request updates only.
+     *
+     * @param stateEvent the stateEvent to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withStateEvent(StateEvent stateEvent) {
+	this.stateEvent = stateEvent;
+	return (this);
+    }
+
+    /**
+     * Flag indicating if a merge request should remove the source branch when merging.
+     *
+     * @param removeSourceBranch the removeSourceBranch to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withRemoveSourceBranch(Boolean removeSourceBranch) {
+	this.removeSourceBranch = removeSourceBranch;
+	return (this);
+    }
+
+    /**
+     * Squash commits into a single commit when merging.
+     *
+     * @param squash the squash to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withSquash(Boolean squash) {
+	this.squash = squash;
+	return (this);
+    }
+
+    /**
+     * Flag indicating if the merge request’s discussion is locked. If the discussion is locked only
+     * project members can add, edit or resolve comments. This is for merge request updates only.
+     *
+     * @param discussionLocked the discussionLocked to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withDiscussionLocked(Boolean discussionLocked) {
+	this.discussionLocked = discussionLocked;
+	return (this);
+    }
+
+    /**
+     * Allow commits from members who can merge to the target branch.
+     *
+     * @param allowCollaboration the allowCollaboration to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withAllowCollaboration(Boolean allowCollaboration) {
+	this.allowCollaboration = allowCollaboration;
+	return (this);
+    }
+
+    /**
+     * Set the approvals_before_merge field value. This is for merge request creation only.
+     *
+     * @param approvalsBeforeMerge the approvalsBeforeMerge to set
+     * @return the reference to this MergeRequestParams instance
+     */
+    public MergeRequestParams withApprovalsBeforeMerge(Integer approvalsBeforeMerge) {
+	this.approvalsBeforeMerge = approvalsBeforeMerge;
+	return (this);
+    }
+
+    /**
+     * Get the form params specified by this instance.
+     *
+     * @param isCreate set to true if this is for a create merge request API call,
+     *                 set to false if this is for an update merge request
+     * @return a GitLabApiForm instance holding the form parameters for this MergeRequestParams instance
+     */
+    public GitLabApiForm getForm(boolean isCreate) {
+
+	GitLabApiForm form = new GitLabApiForm()
+            .withParam("target_branch", targetBranch, isCreate)
+            .withParam("title", title, isCreate)
+            .withParam("assignee_id", assigneeId)
+            .withParam("assignee_ids", assigneeIds)
+            .withParam("milestone_id", milestoneId)
+            .withParam("labels", (labels != null ? String.join(",", labels) : null))
+            .withParam("description", description)
+            .withParam("remove_source_branch", removeSourceBranch)
+            .withParam("squash", squash)
+            .withParam("allow_collaboration", allowCollaboration);
+
+	if (isCreate) {
+	    form.withParam("source_branch", sourceBranch, true)
+		.withParam("target_project_id", targetProjectId)
+		.withParam("approvals_before_merge", approvalsBeforeMerge);
+	} else {
+	    form.withParam("state_event", stateEvent)
+	        .withParam("discussion_locked", discussionLocked);
+	}
+
+	return (form);
+    }
+}

src/test/java/org/gitlab4j/api/TestMergeRequestApi.java

 package org.gitlab4j.api;
 
-import static org.hamcrest.Matchers.hasEntry;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThat;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.when;
-import static org.mockito.MockitoAnnotations.initMocks;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assume.assumeNotNull;
 
-import java.util.Collections;
-
-import javax.ws.rs.core.MultivaluedMap;
+import java.util.Optional;
+import java.util.stream.Stream;
 
+import org.gitlab4j.api.models.Branch;
 import org.gitlab4j.api.models.MergeRequest;
+import org.gitlab4j.api.models.MergeRequestParams;
+import org.gitlab4j.api.models.Project;
+import org.gitlab4j.api.models.RepositoryFile;
+import org.gitlab4j.api.models.User;
+import org.junit.AfterClass;
 import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.FixMethodOrder;
 import org.junit.Test;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Captor;
-import org.mockito.Mock;
-import org.mockito.Mockito;
+import org.junit.experimental.categories.Category;
+import org.junit.runners.MethodSorters;
 
-public class TestMergeRequestApi {
+/**
+ * In order for these tests to run you must set the following properties in test-gitlab4j.properties
+ *
+ * TEST_NAMESPACE
+ * TEST_PROJECT_NAME
+ * TEST_HOST_URL
+ * TEST_PRIVATE_TOKEN
+ *
+ * If any of the above are NULL, all tests in this class will be skipped.
+ *
+ * NOTE: &FixMethodOrder(MethodSorters.NAME_ASCENDING) is very important to insure that testCreate() is executed first.
+ */
+@Category(IntegrationTest.class)
+@FixMethodOrder(MethodSorters.NAME_ASCENDING)
+public class TestMergeRequestApi extends AbstractIntegrationTest {
 
-    @Mock private GitLabApi gitLabApi;
-    @Mock private GitLabApiClient gitLabApiClient;
-    @Captor private ArgumentCaptor<MultivaluedMap<String, String>> attributeCaptor;
-    private MockResponse response;
+    private static final String TEST_BRANCH_NAME = "feature/gitlab4j-merge-request-test";
+    private static final String TEST_MR_TITLE = "Merge Request test: gitlab4j-merge-request-test";
+    private static final String TEST_DESCRIPTION = "Description for Merge Request test";
 
-    @SuppressWarnings("deprecation")
-    @Before
-    public void setUp() throws Exception {
-        initMocks(this);
-        response = new MockResponse(MergeRequest.class, "merge-request.json", null);
-        when(gitLabApi.getApiClient()).thenReturn(gitLabApiClient);
-
-        when(gitLabApiClient.validateSecretToken(any())).thenReturn(true);
-        when(gitLabApiClient.put(attributeCaptor.capture(), Mockito.<Object>anyVararg()))
-                .thenReturn(response);
+    private static GitLabApi gitLabApi;
+    private static Project testProject;
+    private static User currentUser;
+
+    public TestMergeRequestApi() {
+        super();
     }
 
-    @Test
-    public void whenAllArgumentsNull_thenNoAttributesSent() throws Exception {
-        new MergeRequestApi(gitLabApi).updateMergeRequest(1, 2, null, null, null, null, null, null,
-                null, null, null, null, null);
-        assertEquals(0, attributeCaptor.getValue().size());
+    @BeforeClass
+    public static void setup() {
+
+        // Must setup the connection to the GitLab test server
+        gitLabApi = baseTestSetup();
+        testProject = getTestProject();
+        currentUser = getCurrentUser();
+
+        teardown();
     }
 
-    @Test
-    public void falseBooleansAreSerializedCorrectly() throws Exception {
-        new MergeRequestApi(gitLabApi).updateMergeRequest(1, 2, null, null, null, null, null, null,
-                null, null, null, null, false);
-        assertThat(attributeCaptor.getValue(),
-                hasEntry("allow_collaboration", Collections.singletonList("false")));
+    @AfterClass
+    public static void teardown() {
+
+	if (testProject == null) {
+	    return;
+	}
+
+	try {
+
+	    Stream<MergeRequest> mergeRequests = gitLabApi.getMergeRequestApi().getMergeRequestsStream(testProject);
+	    MergeRequest mergeRequest = mergeRequests.filter(
+		    m -> TEST_MR_TITLE.equals(m.getTitle())).findFirst().orElse(null);
+	    if (mergeRequest != null) {
+		gitLabApi.getMergeRequestApi().deleteMergeRequest(testProject, mergeRequest.getIid());
+	    }
+
+	} catch (GitLabApiException ignore) {
+	}
+
+        try {
+            gitLabApi.getRepositoryApi().deleteBranch(testProject, TEST_BRANCH_NAME);
+        } catch (GitLabApiException ignore) {
+        }
+    }
+
+    @Before
+    public void beforeMethod() {
+        assumeNotNull(testProject);
     }
 
     @Test
-    public void trueBooleansAreSerializedCorrectly() throws Exception {
-        new MergeRequestApi(gitLabApi).updateMergeRequest(1, 2, null, null, null, null, null, null,
-                null, null, null, null, true);
-        assertThat(attributeCaptor.getValue(),
-                hasEntry("allow_collaboration", Collections.singletonList("true")));
+    public void testCreateAndUpdateMergeRequest() throws GitLabApiException {
+
+	// Create a test branch
+        Branch branch = gitLabApi.getRepositoryApi().createBranch(testProject, TEST_BRANCH_NAME, "master");
+        assertNotNull(branch);
+
+        // Create a new file in the test branch
+        RepositoryFile repoFile = new RepositoryFile();
+        repoFile.setFilePath("README-FOR-TESTING-MERGE-REQUEST.md");
+        repoFile.setContent("This is content");
+        gitLabApi.getRepositoryFileApi().createFile(testProject, repoFile, TEST_BRANCH_NAME, "Initial commit.");
+
+        MergeRequest mr = null;
+        try {
+
+            MergeRequestParams params = new MergeRequestParams()
+                .withSourceBranch(TEST_BRANCH_NAME)
+                .withTargetBranch("master")
+                .withTitle(TEST_MR_TITLE);
+            mr = gitLabApi.getMergeRequestApi().createMergeRequest(testProject, params);
+            assertEquals(TEST_MR_TITLE, mr.getTitle());
+
+            params = new MergeRequestParams()
+                .withAssigneeId(currentUser.getId())
+                .withDescription(TEST_DESCRIPTION)
+                .withDiscussionLocked(true);
+            MergeRequest updatedMr = gitLabApi.getMergeRequestApi().updateMergeRequest(testProject, mr.getIid(), params);
+            assertEquals(currentUser.getId(), updatedMr.getAssignee().getId());
+            assertEquals(TEST_DESCRIPTION, updatedMr.getDescription());
+            assertEquals(true, updatedMr.getDiscussionLocked());
+
+            gitLabApi.getMergeRequestApi().deleteMergeRequest(testProject,  mr.getIid());
+            Optional<MergeRequest> deletedMr =
+                gitLabApi.getMergeRequestApi().getOptionalMergeRequest(testProject, mr.getIid());
+            mr = null;
+            assertFalse(deletedMr.isPresent());
+
+        } finally {
+
+            if (mr != null) {
+                try {
+                    gitLabApi.getMergeRequestApi().deleteMergeRequest(testProject,  mr.getIid());
+                } catch (Exception ignore) {
+                }
+            }
+
+            try {
+                gitLabApi.getRepositoryApi().deleteBranch(testProject, TEST_BRANCH_NAME);
+            } catch (GitLabApiException ignore) {
+            }
+        }
     }
 }

src/test/java/org/gitlab4j/api/TestUnitMergeRequestApi.java

+package org.gitlab4j.api;
+
+import static org.hamcrest.Matchers.hasEntry;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+import static org.mockito.MockitoAnnotations.initMocks;
+
+import java.util.Collections;
+
+import javax.ws.rs.core.MultivaluedMap;
+
+import org.gitlab4j.api.models.MergeRequest;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+
+public class TestUnitMergeRequestApi {
+
+    @Mock private GitLabApi mockGitLabApi;
+    @Mock private GitLabApiClient mockedGitLabApiClient;
+    @Captor private ArgumentCaptor<MultivaluedMap<String, String>> attributeCaptor;
+    private MockResponse mockedResponse;
+
+    @Before
+    public void setUp() throws Exception {
+        initMocks(this);
+        mockedResponse = new MockResponse(MergeRequest.class, "merge-request.json", null);
+        when(mockGitLabApi.getApiClient()).thenReturn(mockedGitLabApiClient);
+
+        when(mockedGitLabApiClient.validateSecretToken(any())).thenReturn(true);
+        when(mockedGitLabApiClient.put(attributeCaptor.capture(), Mockito.<Object>any()))
+                .thenReturn(mockedResponse);
+    }
+
+    @Test
+    public void whenAllArgumentsNull_thenNoAttributesSent() throws Exception {
+        new MergeRequestApi(mockGitLabApi).updateMergeRequest(1, 2, null, null, null, null, null, null,
+                null, null, null, null, null);
+        assertEquals(0, attributeCaptor.getValue().size());
+    }
+
+    @Test
+    public void falseBooleansAreSerializedCorrectly() throws Exception {
+        new MergeRequestApi(mockGitLabApi).updateMergeRequest(1, 2, null, null, null, null, null, null,
+                null, null, null, null, false);
+        assertThat(attributeCaptor.getValue(),
+                hasEntry("allow_collaboration", Collections.singletonList("false")));
+    }
+
+    @Test
+    public void trueBooleansAreSerializedCorrectly() throws Exception {
+        new MergeRequestApi(mockGitLabApi).updateMergeRequest(1, 2, null, null, null, null, null, null,
+                null, null, null, null, true);
+        assertThat(attributeCaptor.getValue(),
+                hasEntry("allow_collaboration", Collections.singletonList("true")));
+    }
+}