From 94029a0173f361fdf7ae8fe3828b68539f57e6c1 Mon Sep 17 00:00:00 2001
From: Sebastian Zarnekow <Sebastian.Zarnekow@itemis.de>
Date: Wed, 6 Mar 2013 19:19:05 +0100
Subject: [PATCH] [xtext][junit] Reduce the number of injectors in the tests

Instead of the map of Class<Test> -> InjectProvider a
mapping of Class<InjectorProvider> -> InjectorProvider
is used.
---
 .../org/eclipse/xtext/junit4/XtextRunner.java | 28 ++------
 .../junit4/internal/InjectorProviders.java    | 71 +++++++++++++++++++
 2 files changed, 75 insertions(+), 24 deletions(-)
 create mode 100644 plugins/org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/internal/InjectorProviders.java

diff --git a/plugins/org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/XtextRunner.java b/plugins/org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/XtextRunner.java
index 985ea9524..deb9a5532 100644
--- a/plugins/org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/XtextRunner.java
+++ b/plugins/org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/XtextRunner.java
@@ -7,24 +7,18 @@
  *******************************************************************************/
 package org.eclipse.xtext.junit4;
 
-import static org.eclipse.xtext.util.Exceptions.*;
-
-import java.util.Map;
-
+import org.eclipse.xtext.junit4.internal.InjectorProviders;
 import org.junit.runners.BlockJUnit4ClassRunner;
 import org.junit.runners.model.FrameworkMethod;
 import org.junit.runners.model.InitializationError;
 import org.junit.runners.model.Statement;
 
-import com.google.common.collect.Maps;
 import com.google.inject.Injector;
 
 /**
  * @author Michael Clay - Initial contribution and API
  */
 public class XtextRunner extends BlockJUnit4ClassRunner {
-	private static Map<Class<?>, IInjectorProvider> injectorProviderClassCache = Maps.newHashMap();
-
 	public XtextRunner(Class<?> klass) throws InitializationError {
 		super(klass);
 	}
@@ -64,29 +58,15 @@ public class XtextRunner extends BlockJUnit4ClassRunner {
 	}
 
 	protected IInjectorProvider getOrCreateInjectorProvider() {
-		IInjectorProvider injectorProvider = getInjectorProvider();
-		if (injectorProvider == null) {
-			injectorProvider = createInjectorProvider();
-			injectorProviderClassCache.put(getTestClass().getJavaClass(), injectorProvider);
-		}
-		return injectorProvider;
+		return InjectorProviders.getOrCreateInjectorProvider(getTestClass());
 	}
 
 	protected IInjectorProvider getInjectorProvider() {
-		return injectorProviderClassCache.get(getTestClass().getJavaClass());
+		return InjectorProviders.getInjectorProvider(getTestClass());
 	}
 
 	protected IInjectorProvider createInjectorProvider() {
-		IInjectorProvider injectorProvider = null;
-		InjectWith injectWith = getTestClass().getJavaClass().getAnnotation(InjectWith.class);
-		if (injectWith != null) {
-			try {
-				injectorProvider = injectWith.value().newInstance();
-			} catch (Exception e) {
-				throwUncheckedException(e);
-			}
-		}
-		return injectorProvider;
+		return InjectorProviders.createInjectorProvider(getTestClass());
 	}
 
 }
diff --git a/plugins/org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/internal/InjectorProviders.java b/plugins/org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/internal/InjectorProviders.java
new file mode 100644
index 000000000..457f4e441
--- /dev/null
+++ b/plugins/org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/internal/InjectorProviders.java
@@ -0,0 +1,71 @@
+/*******************************************************************************
+ * Copyright (c) 2013 itemis AG (http://www.itemis.eu) and others.
+ * 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
+ *******************************************************************************/
+package org.eclipse.xtext.junit4.internal;
+
+import static org.eclipse.xtext.util.Exceptions.*;
+
+import org.eclipse.xtext.junit4.IInjectorProvider;
+import org.eclipse.xtext.junit4.InjectWith;
+import org.junit.runners.model.TestClass;
+
+import com.google.common.annotations.Beta;
+import com.google.common.collect.ClassToInstanceMap;
+import com.google.common.collect.MutableClassToInstanceMap;
+
+/**
+ * Maintains a map of injector provider types to their instance.
+ * 
+ * Clients will usually use {@link #getOrCreateInjectorProvider(TestClass)} to obtain
+ * an valid injector provider in the context of a given {@link TestClass}.
+ * 
+ * @author Sebastian Zarnekow - Initial contribution and API
+ */
+@Beta
+public class InjectorProviders {
+
+	private static ClassToInstanceMap<IInjectorProvider> injectorProviderClassCache = MutableClassToInstanceMap.create();
+	
+	public static IInjectorProvider getOrCreateInjectorProvider(TestClass testClass) {
+		InjectWith injectWith = testClass.getJavaClass().getAnnotation(InjectWith.class);
+		if (injectWith != null) {
+			Class<? extends IInjectorProvider> klass = injectWith.value();
+			IInjectorProvider injectorProvider = injectorProviderClassCache.get(klass);
+			if (injectorProvider == null) {
+				try {
+					injectorProvider = klass.newInstance();
+					injectorProviderClassCache.put(klass, injectorProvider);
+				} catch (Exception e) {
+					throwUncheckedException(e);
+				}
+			}
+			return injectorProvider;
+		}
+		return null;
+	}
+
+	public static IInjectorProvider getInjectorProvider(TestClass testClass) {
+		InjectWith injectWith = testClass.getJavaClass().getAnnotation(InjectWith.class);
+		if (injectWith != null) {
+			return injectorProviderClassCache.get(injectWith.value());
+		}
+		return null;
+	}
+
+	public static IInjectorProvider createInjectorProvider(TestClass testClass) {
+		InjectWith injectWith = testClass.getJavaClass().getAnnotation(InjectWith.class);
+		if (injectWith != null) {
+			try {
+				return injectWith.value().newInstance();
+			} catch (Exception e) {
+				throwUncheckedException(e);
+			}
+		}
+		return null;
+	}
+
+}