Add completed() matcher to check whether a build has completed.

src/main/java/jenkins/test/RunMatchers.java

@@ -60,6 +60,13 @@ public static Matcher<Run<?,?>> logContains(String message) {
         return new RunLogMatcher(message);
     }
 
+    /**
+     * Creates a matcher checking whether a build has completed.
+     */
+    public static Matcher<Run<?,?>> completed() {
+        return new CompletedRunMatcher();
+    }
+
     private static class RunResultMatcher extends TypeSafeMatcher<Run<?,?>> {
         @NonNull
         private final Result expectedResult;
@@ -116,4 +123,16 @@ public void describeTo(Description description) {
             description.appendText("log containing ").appendValue(message);
         }
     }
+
+    private static class CompletedRunMatcher extends TypeSafeMatcher<Run<?, ?>> {
+        @Override
+        protected boolean matchesSafely(Run<?, ?> run) {
+            return !run.isLogUpdated();
+        }
+
+        @Override
+        public void describeTo(Description description) {
+            description.appendText("a completed build");
+        }
+    }
 }

src/test/java/jenkins/test/RunMatchersTest.java

@@ -23,6 +23,7 @@
  */
 package jenkins.test;
 
+import static jenkins.test.RunMatchers.completed;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.allOf;
 import static org.hamcrest.Matchers.not;
@@ -49,7 +50,7 @@ public void buildSuccessful() throws Exception {
         var p = j.createFreeStyleProject();
         p.getBuildersList().add(new SleepBuilder(1000));
         var b = p.scheduleBuild2(0).waitForStart();
-        assertThat(j.waitForCompletion(b), isSuccessful());
+        assertThat(j.waitForCompletion(b), allOf(completed(), isSuccessful()));
     }
 
     @Test