Concourse: basic support for 'do' attribute

vscode-extensions/vscode-concourse/src/main/java/org/springframework/ide/vscode/concourse/PipelineYmlSchema.java

@@ -120,15 +120,18 @@ public class PipelineYmlSchema implements YamlSchema {
 		prop(taskStep, "output_mapping", t_string_params);
 
 		YBeanType aggregateStep = f.ybean("AggregateStep");
+		YBeanType doStep = f.ybean("DoStep");
 		
 		YBeanType[] stepTypes = {
 				getStep,
 				putStep,
 				taskStep,
-				aggregateStep
+				aggregateStep,
+				doStep
 		};
 		YBeanUnionType step = f.yunion("Step", stepTypes);
 		prop(aggregateStep, "aggregate", f.yseq(step));
+		prop(doStep, "do", f.yseq(step));
 
 		// shared properties applicable for any type of Step:
 		prop(step, "on_success", step);

vscode-extensions/vscode-concourse/src/main/resources/desc/DoStep/do.md

@@ -0,0 +1,14 @@
+Run steps in series.
+
+	do: [step]
+
+Simply performs the given steps serially, with the same semantics as if they were at the top level step listing.
+
+This can be used to perform multiple steps serially in the branch of an `aggregate` step:
+
+	plan:
+	- aggregate:
+	  - task: unit
+	  - do:
+	    - get: something-else
+	    - task: something-else-unit

vscode-extensions/vscode-concourse/src/test/java/org/springframework/ide/vscode/concourse/PipelineYamlEditorTest.java

@@ -135,6 +135,9 @@ public class PipelineYamlEditorTest {
 				"aggregate:\n" +
 				"    - <*>"
 				, // ==============
+				"do:\n" +
+				"    - <*>"
+				, // ==============
 				"get: <*>"
 				, // ==============
 				"put: <*>"
@@ -261,7 +264,22 @@ public class PipelineYamlEditorTest {
 		
 		editor.assertHoverContains("aggregate", "Performs the given steps in parallel");
 	}
-	
+
+	@Test
+	public void doStepHovers() throws Exception {
+		Editor editor;
+		
+		editor = harness.newEditor(
+				"jobs:\n" +
+				"- name: some-job\n" +
+				"  plan:\n" +
+				"  - do:\n" +
+				"    - get: some-resource\n"
+		);
+		
+		editor.assertHoverContains("do", "performs the given steps serially");
+	}
+
 	@Test
 	public void reconcileSimpleTypes() throws Exception {
 		Editor editor;