Consolidate logic in test rules for getting output dir and operation name

spring-restdocs-core/src/test/java/org/springframework/restdocs/headers/RequestHeadersSnippetTests.java

@@ -93,6 +93,8 @@ public class RequestHeadersSnippetTests extends AbstractSnippetTests {
 
 	@Test
 	public void undocumentedRequestHeader() throws IOException {
+		this.snippet.expectRequestHeaders().withContents(
+				tableWithHeader("Name", "Description").row("`X-Test`", "one"));
 		new RequestHeadersSnippet(
 				Arrays.asList(headerWithName("X-Test").description("one")))
 						.document(this.operationBuilder.request("http://localhost")

spring-restdocs-core/src/test/java/org/springframework/restdocs/headers/ResponseHeadersSnippetTests.java

@@ -81,6 +81,8 @@ public class ResponseHeadersSnippetTests extends AbstractSnippetTests {
 
 	@Test
 	public void undocumentedResponseHeader() throws IOException {
+		this.snippet.expectResponseHeaders().withContents(
+				tableWithHeader("Name", "Description").row("`X-Test`", "one"));
 		new ResponseHeadersSnippet(
 				Arrays.asList(headerWithName("X-Test").description("one"))).document(
 						this.operationBuilder.response().header("X-Test", "test")

spring-restdocs-core/src/test/java/org/springframework/restdocs/test/ExpectedSnippet.java

@@ -20,8 +20,6 @@ import java.io.File;
 import java.io.IOException;
 
 import org.hamcrest.Matcher;
-import org.junit.rules.TestRule;
-import org.junit.runner.Description;
 import org.junit.runners.model.Statement;
 
 import org.springframework.restdocs.snippet.TemplatedSnippet;
@@ -38,7 +36,7 @@ import static org.junit.Assert.assertThat;
  * @author Andy Wilkinson
  * @author Andreas Evers
  */
-public class ExpectedSnippet implements TestRule {
+public class ExpectedSnippet extends OperationTestRule {
 
 	private final TemplateFormat templateFormat;
 
@@ -56,9 +54,10 @@ public class ExpectedSnippet implements TestRule {
 	}
 
 	@Override
-	public Statement apply(final Statement base, Description description) {
-		this.outputDirectory = new File(
-				"build/" + description.getTestClass().getSimpleName());
+	public Statement apply(final Statement base, File outputDirectory,
+			String operationName) {
+		this.outputDirectory = outputDirectory;
+		this.expectedName = operationName;
 		return new ExpectedSnippetStatement(base);
 	}
 

spring-restdocs-core/src/test/java/org/springframework/restdocs/test/OperationBuilder.java

@@ -24,8 +24,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import org.junit.rules.TestRule;
-import org.junit.runner.Description;
 import org.junit.runners.model.Statement;
 
 import org.springframework.http.HttpHeaders;
@@ -57,7 +55,7 @@ import org.springframework.restdocs.templates.mustache.MustacheTemplateEngine;
  *
  * @author Andy Wilkinson
  */
-public class OperationBuilder implements TestRule {
+public class OperationBuilder extends OperationTestRule {
 
 	private final Map<String, Object> attributes = new HashMap<>();
 
@@ -133,22 +131,9 @@ public class OperationBuilder implements TestRule {
 	}
 
 	@Override
-	public Statement apply(final Statement base, final Description description) {
-		return new Statement() {
-
-			@Override
-			public void evaluate() throws Throwable {
-				String operationName = description.getMethodName();
-				int index = operationName.indexOf('[');
-				if (index > 0) {
-					operationName = operationName.substring(0, index);
-				}
-				OperationBuilder.this.prepare(operationName,
-						new File("build/" + description.getTestClass().getSimpleName()));
-				base.evaluate();
-			}
-
-		};
+	public Statement apply(Statement base, File outputDirectory, String operationName) {
+		prepare(operationName, outputDirectory);
+		return base;
 	}
 
 	/**

spring-restdocs-core/src/test/java/org/springframework/restdocs/test/OperationTestRule.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2014-2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.restdocs.test;
+
+import java.io.File;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+/**
+ * Abstract base class for Operation-related {@link TestRule TestRules}.
+ *
+ * @author Andy Wilkinson
+ */
+abstract class OperationTestRule implements TestRule {
+
+	@Override
+	public final Statement apply(Statement base, Description description) {
+		return apply(base, determineOutputDirectory(description),
+				determineOperationName(description));
+	}
+
+	private File determineOutputDirectory(Description description) {
+		return new File("build/" + description.getTestClass().getSimpleName());
+	}
+
+	private String determineOperationName(Description description) {
+		String operationName = description.getMethodName();
+		int index = operationName.indexOf('[');
+		if (index > 0) {
+			operationName = operationName.substring(0, index);
+		}
+		return operationName;
+	}
+
+	protected abstract Statement apply(Statement base, File outputDirectory,
+			String operationName);
+
+}