Show message in HTML report when analyzed class does not match executed (bazel-contrib#819)

Author: Godin

org.jacoco.doc/docroot/doc/changes.html

@@ -39,6 +39,8 @@ <h3>New Features</h3>
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/801">#801</a>).</li>
   <li>HTML report shows message when class has no debug information
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/818">#818</a>).</li>
+  <li>HTML report shows message when analyzed class does not match executed
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/819">#819</a>).</li>
 </ul>
 
 <h3>Fixed Bugs</h3>

org.jacoco.report.test/src/org/jacoco/report/internal/html/page/ClassPageTest.java

@@ -133,6 +133,20 @@ public void should_generate_message_when_no_lines() throws Exception {
 				support.findStr(doc, "/html/body/p[1]"));
 	}
 
+	@Test
+	public void should_generate_message_when_class_id_mismatch()
+			throws Exception {
+		node = new ClassCoverageImpl("Foo", 123, true);
+		node.addMethod(new MethodCoverageImpl("m", "()V", null));
+
+		page = new ClassPage(node, null, new SourceLink(), rootFolder, context);
+		page.render();
+
+		final Document doc = support.parse(output.getFile("Foo.html"));
+		assertEquals("A different version of class was executed at runtime.",
+				support.findStr(doc, "/html/body/p[1]"));
+	}
+
 	private class SourceLink implements ILinkable {
 
 		public String getLink(final ReportOutputFolder base) {

org.jacoco.report/src/org/jacoco/report/internal/html/page/ClassPage.java

@@ -83,6 +83,11 @@ public String getLinkLabel() {
 
 	@Override
 	protected void content(HTMLElement body) throws IOException {
+		if (getNode().isNoMatch()) {
+			body.p().text(
+					"A different version of class was executed at runtime.");
+		}
+
 		if (getNode().getLineCounter().getTotalCount() == 0) {
 			body.p().text(
 					"Class files must be compiled with debug information to show line coverage.");