Test stability: wait for specific child node after expansion

The first test in GlobalConfigurationPageTest frequently fails on Hudson
because it doesn't find the child node "Configuration". It appears that
child nodes in the preference page's tree are added one after another,
so waiting until there is any child is not good enough: "Configuration"
is the second child and might not have appeared yet.

Change-Id: Ic5690b481b111fe98aa6d8da1108d5ee462c6e1a
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

1 files changed, 42 insertions, 0 deletions

diff --git a/org.eclipse.egit.ui.test/src/org/eclipse/egit/ui/test/TestUtil.java b/org.eclipse.egit.ui.test/src/org/eclipse/egit/ui/test/TestUtil.java
index 16520a3a49..555b9788db 100644
--- a/org.eclipse.egit.ui.test/src/org/eclipse/egit/ui/test/TestUtil.java
+++ b/org.eclipse.egit.ui.test/src/org/eclipse/egit/ui/test/TestUtil.java
@@ -603,6 +603,48 @@ public class TestUtil {
 	}
 
 	/**
+	 * Expand a node and wait until it is expanded and has a child node with the
+	 * given name. Use only if the node is expected to have children.
+	 *
+	 * @param treeItem
+	 *            to expand
+	 * @param childName
+	 *            to wait for
+	 * @return the child node
+	 */
+	public static SWTBotTreeItem expandAndWaitFor(final SWTBotTreeItem treeItem,
+			final String childName) {
+		final String text = treeItem.getText();
+		final SWTBotTreeItem[] result = { null };
+		treeItem.expand();
+		new SWTBot().waitUntil(new DefaultCondition() {
+
+			@Override
+			public boolean test() {
+				if (treeItem.widget.isDisposed()) {
+					return true; // Stop waiting and report failure below.
+				}
+				try {
+					result[0] = treeItem.getNode(childName);
+					return true;
+				} catch (WidgetNotFoundException e) {
+					return false;
+				}
+			}
+
+			@Override
+			public String getFailureMessage() {
+				return "Child " + childName + " not found under " + text;
+			}
+		});
+		if (treeItem.widget.isDisposed()) {
+			fail("Widget disposed while waiting for child node " + text + '.'
+					+ childName);
+		}
+		return result[0];
+	}
+
+	/**
 	 * Navigates in the given tree to the node denoted by the labels in the
 	 * path, using {@link #getNode(SWTBotTreeItem[], String)} to find children.
 	 *