[Spring] Do not share ContextCache between threads

 The TestContextManager(Class<?>) uses a static ContextCache. This meant
 that step definitions from different threads could be registered in
 same context multiple times when running in parallel.

 This is resolved by creating a ThreadLocal ContextCache for each
 SpringFactory.

 Related issues:
  - https://travis-ci.org/cucumber/cucumber-jvm/jobs/244215644
  - #1148

Author: mpkorstanje

spring/src/main/java/cucumber/runtime/java/spring/SpringFactory.java

@@ -1,7 +1,10 @@
 package cucumber.runtime.java.spring;
 
-import cucumber.runtime.CucumberException;
+import static org.springframework.test.context.FixBootstrapUtils.createBootstrapContext;
+import static org.springframework.test.context.FixBootstrapUtils.resolveTestContextBootstrapper;
+
 import cucumber.api.java.ObjectFactory;
+import cucumber.runtime.CucumberException;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
@@ -202,12 +205,14 @@ private boolean annotatedWithSupportedSpringRootTestAnnotations(Class<?> type) {
 
 class CucumberTestContextManager extends TestContextManager {
 
-    public CucumberTestContextManager(Class<?> testClass) {
-        super(testClass);
+    CucumberTestContextManager(Class<?> testClass) {
+        // Does the same as TestContextManager(Class<?>) but creates a
+        // DefaultCacheAwareContextLoaderDelegate that uses a thread local contextCache.
+        super(resolveTestContextBootstrapper(createBootstrapContext(testClass)));
         registerGlueCodeScope(getContext());
     }
 
-    public ConfigurableListableBeanFactory getBeanFactory() {
+    ConfigurableListableBeanFactory getBeanFactory() {
         return getContext().getBeanFactory();
     }
 

spring/src/main/java/org/springframework/test/context/FixBootstrapUtils.java

@@ -0,0 +1,25 @@
+package org.springframework.test.context;
+
+import org.springframework.test.context.cache.ContextCache;
+import org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate;
+import org.springframework.test.context.cache.DefaultContextCache;
+import org.springframework.test.context.support.DefaultBootstrapContext;
+
+public class FixBootstrapUtils extends BootstrapUtils {
+
+    private static ThreadLocal<ContextCache> contextCache = new ThreadLocal<ContextCache>(){
+        @Override
+        protected ContextCache initialValue() {
+            return new DefaultContextCache();
+        }
+    };
+
+    public static BootstrapContext createBootstrapContext(Class<?> testClass) {
+        CacheAwareContextLoaderDelegate contextLoader = new DefaultCacheAwareContextLoaderDelegate(contextCache.get());
+        return new DefaultBootstrapContext(testClass, contextLoader);
+    }
+
+    public static TestContextBootstrapper resolveTestContextBootstrapper(BootstrapContext bootstrapContext) {
+        return BootstrapUtils.resolveTestContextBootstrapper(bootstrapContext);
+    }
+}