Add ChangeBuildDescriptionActionDescriptor

.gitignore

@@ -1,4 +1,3 @@
 /.idea
-/docs
 **/*.iml
 target/

src/main/java/pl/damianszczepanik/jenkins/buildhistorymanager/descriptors/actions/ChangeBuildDescriptionActionDescriptor.java

@@ -0,0 +1,26 @@
+package pl.damianszczepanik.jenkins.buildhistorymanager.descriptors.actions;
+
+import hudson.Extension;
+import hudson.model.Descriptor;
+import org.jenkinsci.Symbol;
+import pl.damianszczepanik.jenkins.buildhistorymanager.model.actions.Action;
+import pl.damianszczepanik.jenkins.buildhistorymanager.model.actions.ChangeBuildDescriptionAction;
+
+/**
+ * Descriptor implementation needed to render UI for {@link ChangeBuildDescriptionAction}.
+ *
+ * @author Damian Szczepanik (damianszczepanik@github)
+ */
+@Extension
+@Symbol("ChangeBuildDescription")
+public class ChangeBuildDescriptionActionDescriptor extends Descriptor<Action> {
+
+    public ChangeBuildDescriptionActionDescriptor() {
+        super(ChangeBuildDescriptionAction.class);
+    }
+
+    @Override
+    public String getDisplayName() {
+        return "Change build description";
+    }
+}

src/main/java/pl/damianszczepanik/jenkins/buildhistorymanager/model/actions/ChangeBuildDescriptionAction.java

@@ -25,6 +25,11 @@ public ChangeBuildDescriptionAction() {
     @Override
     public void perform(Run<?, ?> run) throws IOException, InterruptedException {
         // null-safe concatenation
-        run.setDescription(PRE_DESCRIPTION + StringUtils.defaultString(run.getDescription()));
+        String description = StringUtils.defaultString(run.getDescription());
+
+        // do not append if already updated
+        if (!description.startsWith(PRE_DESCRIPTION)) {
+            run.setDescription(PRE_DESCRIPTION + description);
+        }
     }
 }

src/main/resources/pl/damianszczepanik/jenkins/buildhistorymanager/model/actions/ChangeBuildDescriptionAction/help.html

@@ -0,0 +1,10 @@
+<p><b>Description</b></p>
+<p>Updates build description.</p>
+
+<p><b>Use cases</b></p>
+<p>This action is helpful for testing and debugging. It does not change or delete the build what might be hard to
+    rollback. Instead, it allows to test conditions before final action is used.</p>
+
+<p>The result of this action is a string <code>[build-history-manager]</code> which is prepend to job description.</p>
+<p>Use this action as long as the final result of condition is not examined.
+    This is helpful also for users who do not have access to Jenkins logs.</p>

src/test/java/pl/damianszczepanik/jenkins/buildhistorymanager/descriptors/actions/ChangeBuildDescriptionActionDescriptorTest.java

@@ -0,0 +1,32 @@
+package pl.damianszczepanik.jenkins.buildhistorymanager.descriptors.actions;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import hudson.model.AbstractDescribableImpl;
+import hudson.model.Descriptor;
+import org.jenkinsci.plugins.structs.SymbolLookup;
+import org.junit.Rule;
+import org.junit.Test;
+import org.jvnet.hudson.test.JenkinsRule;
+
+/**
+ * @author Damian Szczepanik (damianszczepanik@github)
+ */
+public class ChangeBuildDescriptionActionDescriptorTest {
+
+    @Rule
+    public JenkinsRule j = new JenkinsRule();
+
+    @Test
+    public void getDisplayName_ReturnsDescriptorName() {
+
+        // given
+        Descriptor descriptor = SymbolLookup.get().findDescriptor(AbstractDescribableImpl.class, "ChangeBuildDescription");
+
+        // when
+        String displayName = descriptor.getDisplayName();
+
+        // then
+        assertThat(displayName).isEqualTo("Change build description");
+    }
+}

src/test/java/pl/damianszczepanik/jenkins/buildhistorymanager/model/actions/ChangeBuildDescriptionActionTest.java

@@ -12,17 +12,39 @@
  */
 public class ChangeBuildDescriptionActionTest {
 
+    private static final String PRE_DESCRIPTION = "[build-history-manager]\n";
+
     @Test
-    public void perform_DescriptionUpdate() throws IOException, InterruptedException {
+    public void perform__UpdatedAgain() throws IOException, InterruptedException {
 
         // given
         ChangeBuildDescriptionAction action = new ChangeBuildDescriptionAction();
         RunStub run = new RunStub();
 
+        final String oldDescription = "Yellow Duck";
+        run.setDescription(oldDescription);
+
+        // when
+        action.perform(run);
+
+        // then
+        assertThat(run.getDescription()).startsWith(PRE_DESCRIPTION + oldDescription);
+    }
+
+    @Test
+    public void perform_OnUpdatedDescription_DoesNotUpdatedAgain() throws IOException, InterruptedException {
+
+        // given
+        ChangeBuildDescriptionAction action = new ChangeBuildDescriptionAction();
+        RunStub run = new RunStub();
+
+        final String oldDescription = "Yellow Duck";
+        run.setDescription(PRE_DESCRIPTION + oldDescription);
+
         // when
         action.perform(run);
 
         // then
-        assertThat(run.getDescription()).startsWith("[build-history-manager]");
+        assertThat(run.getDescription()).startsWith(PRE_DESCRIPTION + oldDescription);
     }
 }