PreloadCheck class for extension pre-install checks

extensions/browser/policy_check_unittest.cc

+// Copyright 2017 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.
+
+#include <vector>
+
+#include "base/bind.h"
+#include "base/memory/ref_counted.h"
+#include "base/strings/string16.h"
+#include "base/strings/utf_string_conversions.h"
+#include "content/public/test/test_browser_context.h"
+#include "extensions/browser/extension_system.h"
+#include "extensions/browser/management_policy.h"
+#include "extensions/browser/mock_extension_system.h"
+#include "extensions/browser/policy_check.h"
+#include "extensions/browser/preload_check.h"
+#include "extensions/browser/preload_check_test_util.h"
+#include "extensions/browser/test_extensions_browser_client.h"
+#include "extensions/common/constants.h"
+#include "extensions/common/extension.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace extensions {
+
+namespace {
+
+const char kDummyPolicyError[] = "Cannot install extension";
+
+class ManagementPolicyMock : public extensions::ManagementPolicy::Provider {
+ public:
+  ManagementPolicyMock(const Extension* extension, bool may_load)
+      : extension_(extension), may_load_(may_load) {}
+
+  std::string GetDebugPolicyProviderName() const override {
+    return "ManagementPolicyMock";
+  }
+
+  bool UserMayLoad(const Extension* extension,
+                   base::string16* error) const override {
+    EXPECT_EQ(extension_, extension);
+    if (!may_load_)
+      *error = base::UTF8ToUTF16(kDummyPolicyError);
+    return may_load_;
+  }
+
+ private:
+  const Extension* extension_;
+  bool may_load_;
+};
+
+class TestExtensionSystem : public MockExtensionSystem {
+ public:
+  explicit TestExtensionSystem(content::BrowserContext* context)
+      : MockExtensionSystem(context) {}
+  ~TestExtensionSystem() override {}
+
+  ManagementPolicy* management_policy() override { return &management_policy_; }
+
+ private:
+  ManagementPolicy management_policy_;
+};
+
+}  // namespace
+
+class PolicyCheckTest : public testing::Test {
+ public:
+  PolicyCheckTest() : extensions_browser_client_(&context_) {}
+  ~PolicyCheckTest() override {}
+
+  void SetUp() override {
+    ExtensionsBrowserClient::Set(&extensions_browser_client_);

[Devlin, 2017/03/08 03:01:46]

This not being torn down causes badness.

Additionally, unittests that run in the same process will share this same test
client - is that what you want?

[michaelpg, 2017/03/09 01:53:30]

I'm not quite sure what you mean/how the unit test process model works. Do
unrelated tests really run in parallel threads in the same process? Chrome uses
so much global state that I wouldn't expect that to work.

I figure I'm doing something similar to this:
https://cs.chromium.org/chromium/src/chrome/browser/extensions/extension_reen...

[michaelpg, 2017/03/13 19:18:30]

Here's an example from //extensions/browser that is better than what I'm doing,
but still sets the global ExtensionBrowserClient's ExtensionSystemFactory to a
fake:

https://cs.chromium.org/chromium/src/extensions/browser/updater/update_servic...

Can I follow an example like that test, or wouldn't that cause problems for
other tests run simultaneously in the same process? Appreciate some help here
:-\

[michaelpg, 2017/03/13 20:11:49]

Looks like ExtensionsTest itself calls ExtensionsBrowserClient::Set with a new
TestExtensionsBrowserClient in SetUp(), so two of those running in parallel in
the same process would be a problem. But these tests *seem* to run in sequence
within a particular process (i'm only seeing parallelization at the process
level). (Which makes sense as otherwise the tests would be a lot crashier.)

I'll derive from ExtensionsTest (so I don't have to set up and tear down
manually) and see how that goes.

+    extensions_browser_client_.set_extension_system_factory(&factory_);
+
+    base::DictionaryValue manifest_dict;
+    manifest_dict.SetString("name", "dummy name");
+    manifest_dict.SetString("version", "1");
+    std::string error;
+
+    extension_ =
+        Extension::Create(base::FilePath(), extensions::Manifest::UNPACKED,
+                          manifest_dict, Extension::NO_FLAGS, &error);
+    EXPECT_TRUE(extension_.get()) << error;
+  }
+
+ protected:
+  content::TestBrowserContext context_;
+  TestExtensionsBrowserClient extensions_browser_client_;
+  MockExtensionSystemFactory<TestExtensionSystem> factory_;
+  scoped_refptr<Extension> extension_;
+};
+
+// Test a valid extension.
+TEST_F(PolicyCheckTest, PolicySuccess) {
+  ManagementPolicyMock policy(extension_.get(), true);
+  extensions::ExtensionSystem::Get(&context_)

[Devlin, 2017/03/08 03:01:46]

no need for extensions:: namespace

[michaelpg, 2017/03/09 01:53:30]

Done.

+      ->management_policy()
+      ->RegisterProvider(&policy);
+
+  PreloadCheckObserver observer;
+  PolicyCheck policy_check(&context_, extension_.get());
+  policy_check.Start(base::Bind(&PreloadCheckObserver::OnCheckComplete,
+                                base::Unretained(&observer)));
+  EXPECT_EQ(1, observer.call_count());
+  EXPECT_EQ(0u, observer.errors().size());
+  base::string16 message;
+  EXPECT_FALSE(policy_check.GetErrorMessage(&message));
+}
+
+// Test an invalid extension.
+TEST_F(PolicyCheckTest, PolicyFailure) {
+  ManagementPolicyMock policy(extension_.get(), false);
+  extensions::ExtensionSystem::Get(&context_)
+      ->management_policy()
+      ->RegisterProvider(&policy);
+
+  PreloadCheckObserver observer;
+  PolicyCheck policy_check(&context_, extension_.get());
+  policy_check.Start(base::Bind(&PreloadCheckObserver::OnCheckComplete,
+                                base::Unretained(&observer)));
+  EXPECT_EQ(1, observer.call_count());
+  EXPECT_EQ(1u, observer.errors().size());
+  EXPECT_EQ(1u, observer.errors().count(PreloadCheck::DISALLOWED_BY_POLICY));
+  base::string16 message;
+  EXPECT_TRUE(policy_check.GetErrorMessage(&message));
+  EXPECT_EQ(base::UTF8ToUTF16(kDummyPolicyError), message);
+}
+
+}  // namespace extensions