extends LinkEnricher api to append link arrays to the response

scm-core/src/main/java/sonia/scm/api/v2/resources/LinkAppender.java

@@ -15,4 +15,33 @@ public interface LinkAppender {
    * @param href link uri
    */
   void appendOne(String rel, String href);
+
+  /**
+   * Returns a builder which is able to append an array of links to the resource.
+   *
+   * @param rel name of link relation
+   * @return multi link builder
+   */
+  LinkArrayBuilder arrayBuilder(String rel);
+
+
+  /**
+   * Builder for link arrays.
+   */
+  interface LinkArrayBuilder {
+
+    /**
+     * Append an link to the array.
+     *
+     * @param name name of link
+     * @param href link target
+     * @return {@code this}
+     */
+    LinkArrayBuilder append(String name, String href);
+
+    /**
+     * Builds the array and appends the it to the json response.
+     */
+    void build();
+  }
 }

scm-webapp/src/main/java/sonia/scm/api/v2/resources/EdisonLinkAppender.java

@@ -3,6 +3,9 @@ package sonia.scm.api.v2.resources;
 import de.otto.edison.hal.Link;
 import de.otto.edison.hal.Links;
 
+import java.util.ArrayList;
+import java.util.List;
+
 class EdisonLinkAppender implements LinkAppender {
 
   private final Links.Builder builder;
@@ -15,4 +18,32 @@ class EdisonLinkAppender implements LinkAppender {
   public void appendOne(String rel, String href) {
     builder.single(Link.link(rel, href));
   }
+
+  @Override
+  public LinkArrayBuilder arrayBuilder(String rel) {
+    return new EdisonLinkArrayBuilder(builder, rel);
+  }
+
+  private static class EdisonLinkArrayBuilder implements LinkArrayBuilder {
+
+    private final Links.Builder builder;
+    private final String rel;
+    private final List<Link> linkArray = new ArrayList<>();
+
+    private EdisonLinkArrayBuilder(Links.Builder builder, String rel) {
+      this.builder = builder;
+      this.rel = rel;
+    }
+
+    @Override
+    public LinkArrayBuilder append(String name, String href) {
+      linkArray.add(Link.linkBuilder(rel, href).withName(name).build());
+      return this;
+    }
+
+    @Override
+    public void build() {
+      builder.array(linkArray);
+    }
+  }
 }

scm-webapp/src/test/java/sonia/scm/api/v2/resources/EdisonLinkAppenderTest.java

@@ -0,0 +1,43 @@
+package sonia.scm.api.v2.resources;
+
+import de.otto.edison.hal.Link;
+import de.otto.edison.hal.Links;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static de.otto.edison.hal.Links.linkingTo;
+import static org.assertj.core.api.Assertions.assertThat;
+
+class EdisonLinkAppenderTest {
+
+  private Links.Builder builder;
+  private EdisonLinkAppender appender;
+
+  @BeforeEach
+  void prepare() {
+    builder = linkingTo();
+    appender = new EdisonLinkAppender(builder);
+  }
+
+  @Test
+  void shouldAppendOneLink() {
+    appender.appendOne("self", "https://scm.hitchhiker.com");
+
+    Links links = builder.build();
+    assertThat(links.getLinkBy("self").get().getHref()).isEqualTo("https://scm.hitchhiker.com");
+  }
+
+  @Test
+  void shouldAppendMultipleLinks() {
+    appender.arrayBuilder("items")
+        .append("one", "http://one")
+        .append("two", "http://two")
+        .build();
+
+    List<Link> items = builder.build().getLinksBy("items");
+    assertThat(items).hasSize(2);
+  }
+
+}