Added sanity check for generated code

tests/org.eclipse.n4js.ui.tests/src/org/eclipse/n4js/tests/contentAssist/AllTests.java

@@ -17,7 +17,7 @@
 /**
  */
 @RunWith(Suite.class)
-@SuiteClasses({ TypeReferenceContentAssistPluginUITest.class })
+@SuiteClasses({ TypeReferenceContentAssistPluginUITest.class, ContentAssistParserSanityTest.class })
 public class AllTests {
 	// empty
 }

tests/org.eclipse.n4js.ui.tests/src/org/eclipse/n4js/tests/contentAssist/ContentAssistParserSanityTest.java

@@ -0,0 +1,88 @@
+/**
+ * Copyright (c) 2017 NumberFour AG.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   NumberFour AG - Initial API and implementation
+ */
+package org.eclipse.n4js.tests.contentAssist;
+
+import java.lang.reflect.Method;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+import org.eclipse.n4js.N4JSInjectorProvider;
+import org.eclipse.n4js.services.N4JSGrammarAccess;
+import org.eclipse.n4js.ui.contentassist.antlr.N4JSParser;
+import org.eclipse.n4js.ui.contentassist.antlr.internal.InternalN4JSParser;
+import org.eclipse.xtext.AbstractElement;
+import org.eclipse.xtext.xbase.lib.util.ReflectExtensions;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+import com.google.common.collect.Lists;
+import com.google.inject.Injector;
+
+/**
+ * A test to ensure that all the methods that are generated into the the N4JS content assist parser are actually present
+ * in the InternalN4JSParser.
+ */
+@RunWith(Parameterized.class)
+public class ContentAssistParserSanityTest {
+
+	/**
+	 * The name of the method that need to be present in the InternalN4JSParser class.
+	 */
+	@Parameter
+	public String methodName;
+
+	static class DummyParser extends N4JSParser {
+		@Override
+		protected String getRuleName(AbstractElement element) {
+			return super.getRuleName(element);
+		}
+	}
+
+	/**
+	 * Returns test data.
+	 */
+	@Parameters
+	public static Collection<String> methodNames() {
+		try {
+			N4JSInjectorProvider injectorProvider = new N4JSInjectorProvider();
+			Injector injector = injectorProvider.getInjector();
+			DummyParser dummyParser = new DummyParser();
+			N4JSGrammarAccess grammarAccess = injector.getInstance(N4JSGrammarAccess.class);
+			dummyParser.setGrammarAccess(grammarAccess);
+			injectorProvider.restoreRegistry();
+			dummyParser.getRuleName(null);
+			Map<AbstractElement, String> nameMappings = new ReflectExtensions().get(dummyParser, "nameMappings");
+			List<String> methodNames = Lists.newArrayList(nameMappings.values());
+			Collections.sort(methodNames);
+			return methodNames;
+		} catch (Exception e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	/**
+	 * Tests if the method is actually present in the parser.
+	 */
+	@Test
+	public void testMethodExists() throws Exception {
+		Class<?> type = InternalN4JSParser.class;
+		Method method = type.getDeclaredMethod(methodName);
+		// will throw if missing but just to make it more obvious
+		Assert.assertNotNull("method is not null", method);
+	}
+
+}