sync: Refactor NonBlockingTypeProcessorCore tests

sync/test/engine/simple_mock_server.h

Index: sync/test/engine/simple_mock_server.h
diff --git a/sync/test/engine/simple_mock_server.h b/sync/test/engine/simple_mock_server.h
new file mode 100644
index 0000000000000000000000000000000000000000..bdeefbb27d0c5870c270b321b5d9e7d29740b186
--- /dev/null
+++ b/sync/test/engine/simple_mock_server.h
@@ -0,0 +1,87 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.

[Nicolas Zea, 2014/06/13 21:59:43]

no ifdef header guards? I thought the presubmit checked that.

[rlarocque, 2014/06/14 00:55:19]

I don't know how the presubmit missed it.  Fixed.

+
+#include "sync/engine/non_blocking_sync_common.h"
+
+#include "sync/internal_api/public/base/model_type.h"
+
+namespace syncer {
+
+// A mock server used to test of happy-path update and commit logic.
+//
+// This object supports only one ModelType, which must be specified at
+// initialization time.  It does not support GetUpdates messages.  It does not
+// support simulated errors.
+//
+// This class is useful for testing UpdateHandlers and CommitContributors.
+class SimpleMockServer {

[Nicolas Zea, 2014/06/13 21:59:43]

Are there plans to have other kinds of mock servers (i.e. non-simple)? If not,
that prefix seems unnecessary. I'm also slightly concerned about this being
confused with the fake c++ server, a comment explaining the difference might be
useful. Also, would naming this simple_fake_server make more sense?

[rlarocque, 2014/06/14 00:55:19]

There's MockConnectionManager, which probably deserves the name MockServer more
than this class does.  It does a lot more than mock connections.

I tried to explain a bit of the differences between this class and the
FakeServer in the class comment.  This class has no intention of behaving like a
real server.  The lack of support for more than one ModelType is the most
obvious missing feature.

Would it help if I renamed it to SingleTypeMockServer?  Maybe
UnitTestMockServer?  I could also rename it as SimpleFakeServer if you think
that's a better idea, but I think that would imply some sort of relationship
with the FakeServer.

[Nicolas Zea, 2014/06/16 21:12:58]

I'm good with SingleTypeMockServer

+ public:
+  SimpleMockServer(syncer::ModelType type);

[Nicolas Zea, 2014/06/13 21:59:43]

nit: explicit

[rlarocque, 2014/06/14 00:55:19]

Done.

+  ~SimpleMockServer();
+
+  // Generates a SyncEntity representing a server-delivered update containing
+  // the root node for this SimpleMockServer's type.
+  sync_pb::SyncEntity TypeRootUpdate();
+
+  // Generates a SyncEntity representing a server-delivered update.
+  //
+  // The |version_offset| parameter allows the caller to simulate reflected
+  // updates, redeliveries, and genuine updates.
+  sync_pb::SyncEntity UpdateFromServer(
+      int64 version_offset,
+      const std::string& tag_hash,
+      const sync_pb::EntitySpecifics& specifics);
+
+  // Generates a SyncEntity representing a server-delivered update to delete
+  // an item.
+  sync_pb::SyncEntity TombstoneFromServer(int64 version_offset,
+                                          const std::string& tag_hash);
+
+  // Generates a response to the specified commit message.
+  //
+  // This does not perform any exhausive testing of the sync protocol.  Many of
+  // the request's fields may safely be left blank, and much of the returned
+  // response will be empty, too.
+  //
+  // This is useful mainly for testing objects that implement the
+  // CommitContributor interface.
+  sync_pb::ClientToServerResponse DoSuccessfulCommit(
+      const sync_pb::ClientToServerMessage& message);
+
+  // Getters to return the commit messages sent to the server through
+  // DoSuccessfulCommit().
+  size_t GetNumCommitMessages() const;
+  sync_pb::ClientToServerMessage GetNthCommitMessage(size_t n) const;
+
+  // Getters to return the most recently committed entities for a given
+  // unique_client_tag hash.
+  bool HasCommitEntity(const std::string& tag_hash) const;
+  sync_pb::SyncEntity GetLastCommittedEntity(const std::string& tag_hash) const;
+
+  // Getters that create realistic-looking progress markers and data type
+  // context.
+  sync_pb::DataTypeProgressMarker GetProgress() const;
+  sync_pb::DataTypeContext GetContext() const;
+
+ private:
+  static std::string GenerateId(const std::string& tag_hash);
+
+  // Get and set our emulated server state.
+  int64 GetServerVersion(const std::string& tag_hash) const;
+  void SetServerVersion(const std::string& tag_hash, int64 version);
+
+  const ModelType type_;
+  const std::string type_root_id_;
+
+  // Server version state maps.
+  std::map<const std::string, int64> server_versions_;
+
+  // Log of messages sent to the server.
+  std::vector<sync_pb::ClientToServerMessage> commit_messages_;
+
+  // Map of most recent commits by tag_hash.
+  std::map<const std::string, sync_pb::SyncEntity> committed_items_;

[Nicolas Zea, 2014/06/13 21:59:42]

disallow copy and assign

[rlarocque, 2014/06/14 00:55:19]

Done.

+};
+
+}  // namespace syncer