Add a method for creating a full-stack GitilesServlet for tests

Change-Id: Ieb4fc7c456492f6614535b49d30be73ec600b4b9

gitiles-servlet/src/test/java/com/google/gitiles/TestGitilesServlet.java

diff --git a/gitiles-servlet/src/test/java/com/google/gitiles/TestGitilesServlet.java b/gitiles-servlet/src/test/java/com/google/gitiles/TestGitilesServlet.java
new file mode 100644
index 0000000..b3cb72b
--- /dev/null
+++ b/gitiles-servlet/src/test/java/com/google/gitiles/TestGitilesServlet.java
@@ -0,0 +1,93 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// 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 com.google.gitiles;
+
+import com.google.common.collect.ImmutableList;
+
+import org.eclipse.jgit.errors.RepositoryNotFoundException;
+import org.eclipse.jgit.junit.TestRepository;
+import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.storage.dfs.DfsRepository;
+import org.eclipse.jgit.transport.resolver.RepositoryResolver;
+
+import java.util.Collections;
+import java.util.Enumeration;
+
+import javax.servlet.ServletConfig;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+
+/** Static utility methods for creating {@link GitilesServlet}s for testing. */
+public class TestGitilesServlet {
+  /**
+   * Create a servlet backed by a single test repository.
+   * <p>
+   * The servlet uses the same filter lists as a real servlet, but only knows
+   * about a single repo, having the name returned by
+   * {@link org.eclipse.jgit.storage.dfs.DfsRepositoryDescription#getRepositoryName()}.
+   * Pass a {@link FakeHttpServletRequest} and {@link FakeHttpServletResponse}
+   * to the servlet's {@code service} method to test.
+   *
+   * @param repo the test repo backing the servlet.
+   * @return a servlet.
+   */
+  public static GitilesServlet create(final TestRepository<DfsRepository> repo)
+      throws ServletException {
+    final String repoName =
+        repo.getRepository().getDescription().getRepositoryName();
+    GitilesServlet servlet =
+        new GitilesServlet(new Config(), new DebugRenderer(
+            GitilesServlet.STATIC_PREFIX, null, null, repoName + " test site"),
+            TestGitilesUrls.URLS, new TestGitilesAccess(repo.getRepository()),
+            new RepositoryResolver<HttpServletRequest>() {
+              @Override
+              public Repository open(HttpServletRequest req, String name)
+                  throws RepositoryNotFoundException {
+                if (!repoName.equals(name)) {
+                  throw new RepositoryNotFoundException(name);
+                }
+                return repo.getRepository();
+              }
+            }, null, null);
+
+    servlet.init(new ServletConfig() {
+      @Override
+      public String getInitParameter(String name) {
+        return null;
+      }
+
+      @Override
+      public Enumeration<String> getInitParameterNames() {
+        return Collections.enumeration(ImmutableList.<String> of());
+      }
+
+      @Override
+      public ServletContext getServletContext() {
+        return null;
+      }
+
+      @Override
+      public String getServletName() {
+        return TestGitilesServlet.class.getName();
+      }
+    });
+    return servlet;
+  }
+
+  private TestGitilesServlet() {
+  }
+}