Add support for link type between issues

Fixes #847

Author: jmini

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

@@ -16,6 +16,7 @@
 import org.gitlab4j.api.models.IssueLink;
 import org.gitlab4j.api.models.IssuesStatistics;
 import org.gitlab4j.api.models.IssuesStatisticsFilter;
+import org.gitlab4j.api.models.LinkType;
 import org.gitlab4j.api.models.MergeRequest;
 import org.gitlab4j.api.models.Participant;
 import org.gitlab4j.api.models.TimeStats;
@@ -889,10 +890,31 @@ public Stream<Issue> getIssueLinksStream(Object projectIdOrPath, Long issueIid)
      */
     public IssueLink createIssueLink(Object projectIdOrPath, Long issueIid,
             Object targetProjectIdOrPath, Long targetIssueIid) throws GitLabApiException {
+        return createIssueLink(projectIdOrPath, issueIid, targetProjectIdOrPath, targetIssueIid, null);
+    }
+
+    /**
+     * Creates a two-way relation between two issues. User must be allowed to update both issues in order to succeed.
+     *
+     * <p>NOTE: Only available in GitLab Starter, GitLab Bronze, and higher tiers.</p>
+     *
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues/:issue_iid/links</code></pre>
+     *
+     * @param projectIdOrPath the project in the form of an Long(ID), String(path), or Project instance
+     * @param issueIid the internal ID of a project's issue
+     * @param targetProjectIdOrPath the project in the form of an Long(ID), String(path), or Project instance of the target project
+     * @param targetIssueIid the internal ID of a target project’s issue
+     * @param linkType the type of the relation (optional), defaults to {@link LinkType#RELATES_TO}.
+     * @return an instance of IssueLink holding the link relationship
+     * @throws GitLabApiException if any exception occurs
+     */
+    public IssueLink createIssueLink(Object projectIdOrPath, Long issueIid,
+            Object targetProjectIdOrPath, Long targetIssueIid, LinkType linkType) throws GitLabApiException {
 
         GitLabApiForm formData = new GitLabApiForm()
                 .withParam("target_project_id", getProjectIdOrPath(targetProjectIdOrPath), true)
-                .withParam("target_issue_iid", targetIssueIid, true);
+                .withParam("target_issue_iid", targetIssueIid, true)
+                .withParam("link_type", linkType, false);
 
         Response response = post(Response.Status.OK, formData.asMap(),
                 "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "links");

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

@@ -82,6 +82,10 @@ public String toString() {
     private String taskStatus;
     private TaskCompletionStatus taskCompletionStatus;
 
+    private LinkType linkType;
+    private Date linkCreatedAt;
+    private Date linkUpdatedAt;
+
     public Assignee getAssignee() {
         return assignee;
     }
@@ -351,6 +355,30 @@ public void setTaskCompletionStatus(TaskCompletionStatus taskCompletionStatus) {
         this.taskCompletionStatus = taskCompletionStatus;
     }
 
+    public LinkType getLinkType() {
+        return linkType;
+    }
+
+    public void setLinkType(LinkType linkType) {
+        this.linkType = linkType;
+    }
+
+    public Date getLinkCreatedAt() {
+        return linkCreatedAt;
+    }
+
+    public void setLinkCreatedAt(Date linkCreatedAt) {
+        this.linkCreatedAt = linkCreatedAt;
+    }
+
+    public Date getLinkUpdatedAt() {
+        return linkUpdatedAt;
+    }
+
+    public void setLinkUpdatedAt(Date linkUpdatedAt) {
+        this.linkUpdatedAt = linkUpdatedAt;
+    }
+
     @Override
     public String toString() {
         return (JacksonJson.toJsonString(this));

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

@@ -6,6 +6,7 @@ public class IssueLink {
 
     private Issue sourceIssue;
     private Issue targetIssue;
+    private LinkType linkType;
 
     public Issue getSourceIssue() {
         return sourceIssue;
@@ -23,6 +24,14 @@ public void setTargetIssue(Issue targetIssue) {
         this.targetIssue = targetIssue;
     }
 
+    public LinkType getLinkType() {
+        return linkType;
+    }
+
+    public void setLinkType(LinkType linkType) {
+        this.linkType = linkType;
+    }
+
     @Override
     public String toString() {
         return (JacksonJson.toJsonString(this));

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

@@ -0,0 +1,32 @@
+package org.gitlab4j.api.models;
+
+import org.gitlab4j.api.utils.JacksonJsonEnumHelper;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
+
+/**
+ * Enum to model the type of link between issues or epics
+ */
+public enum LinkType {
+    RELATES_TO,
+    BLOCKS,
+    IS_BLOCKED_BY;
+
+    private static JacksonJsonEnumHelper<LinkType> enumHelper = new JacksonJsonEnumHelper<>(LinkType.class);
+
+    @JsonCreator
+    public static LinkType forValue(String value) {
+        return enumHelper.forValue(value);
+    }
+
+    @JsonValue
+    public String toValue() {
+        return (enumHelper.toString(this));
+    }
+
+    @Override
+    public String toString() {
+        return (enumHelper.toString(this));
+    }
+}

src/test/resources/org/gitlab4j/api/issue-link.json

@@ -46,5 +46,6 @@
     "user_notes_count": 0,
     "web_url": "http://example.com/example/example/issues/14",
     "confidential": false
-  }
+  },
+  "link_type": "is_blocked_by"
 }

src/test/resources/org/gitlab4j/api/linked-issues.json

@@ -22,6 +22,9 @@
     "subscribed" : true,
     "user_notes_count": 0,
     "web_url": "http://example.com/example/example/issues/14",
-    "confidential": false
+    "confidential": false,
+    "link_type": "relates_to",
+    "link_created_at": "2016-01-07T12:44:33.959Z",
+    "link_updated_at": "2016-01-07T12:44:33.959Z"
   }
 ]