Issue #1163 - add unit tests for CPluginUserSettings

test/plugin/UserSettingsTest.cpp

Index: test/plugin/UserSettingsTest.cpp
===================================================================
new file mode 100644
--- /dev/null
+++ b/test/plugin/UserSettingsTest.cpp
@@ -0,0 +1,117 @@
+/*
+ * This file is part of Adblock Plus <http://adblockplus.org/>,
+ * Copyright (C) 2014 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <gtest/gtest.h>
+
+#include <OAIdl.h>
+#include "../../src/plugin/PluginUserSettings.h"
+
+//----------------------------------
+// GetIDsOfNames
+//----------------------------------
+
+namespace
+{
+  void single_method_name_found(std::wstring name, DISPID expected_id)
+  {
+    CPluginUserSettings x;
+    wchar_t *names[1];
+    names[0] = const_cast<wchar_t *>(name.c_str());
+    DISPID ids[1];
+    HRESULT h = x.GetIDsOfNames(IID_NULL, names, 1, 0, ids);
+    ASSERT_EQ(S_OK, h);
+    DISPID id=ids[0];
+    ASSERT_EQ(expected_id, id);
+  }
+
+  void single_method_name_notfound(std::wstring name)
+  {
+    CPluginUserSettings x;
+    wchar_t *names[1];
+    names[0] = const_cast<wchar_t *>(name.c_str());
+    DISPID ids[1];
+    HRESULT h = x.GetIDsOfNames(IID_NULL, names, 1, 0, ids);
+    ASSERT_NE(S_OK, h);
+    // The old version returns a nonstandard error code.
+    if (h == DISP_E_MEMBERNOTFOUND)
+    {
+      return;
+    }
+    EXPECT_EQ(DISP_E_UNKNOWNNAME, h);
+  }
+}
+
+TEST(CPluginUserSettings_GetIDsOfNames_Test, all_defined_found)
+{
+  CPluginUserSettings x;
+  single_method_name_found(L"GetMessage", 0);
+  single_method_name_found(L"GetLanguageCount", 1);
+  single_method_name_found(L"GetLanguageByIndex", 2);
+  single_method_name_found(L"GetLanguageTitleByIndex", 3);
+  single_method_name_found(L"SetLanguage", 4);
+  single_method_name_found(L"GetLanguage", 5);
+  single_method_name_found(L"GetWhitelistDomains", 6);
+  single_method_name_found(L"AddWhitelistDomain", 7);
+  single_method_name_found(L"RemoveWhitelistDomain", 8);
+  single_method_name_found(L"GetAppLocale", 9);
+  single_method_name_found(L"GetDocumentationLink", 10);
+  single_method_name_found(L"IsAcceptableAdsEnabled", 11);
+  single_method_name_found(L"SetAcceptableAdsEnabled", 12);
+}
+
+TEST(CPluginUserSettings_GetIDsOfNames_Test, undefined_not_found)
+{
+  single_method_name_notfound(L"");
+  single_method_name_notfound(L"clearly unknown");
+  single_method_name_notfound(L"GETMESSAGE");
+}
+
+//----------------------------------
+// Invoke
+//----------------------------------
+
+namespace
+{
+  void invoke_invalid_dispatch_id(DISPID id)

[sergei, 2014/08/14 11:37:26]

`id` is not used.

[Eric, 2014/08/14 14:29:53]

Oops. Forgot to replace the -1 below when I refactored from the first version.

+  {
+    CPluginUserSettings x;
+    DISPPARAMS params;

[sergei, 2014/08/14 11:37:26]

DISPPARAMS params = {} looks better, but OK here.

[Eric, 2014/08/14 14:29:53]

Neither this nor the EXCEPINFO below are involved in the test. The only reason
to have them here at all is to provide non-null pointers. If we need more
extensive tests for this, we'll need non-trivial initializer functions for these
anyway, and we can use them at that point.

+    params.rgvarg = nullptr;
+    params.rgdispidNamedArgs = nullptr;
+    params.cArgs = 0;
+    params.cNamedArgs = 0;
+    EXCEPINFO ex;

[sergei, 2014/08/14 11:37:26]

I would also initialize it.

+    HRESULT h = x.Invoke(-1, IID_NULL, 0, 0, &params, nullptr, &ex, nullptr);

[sergei, 2014/08/14 11:37:26]

The first arg should be `id`.

[sergei, 2014/08/14 11:37:26]

Why is the flag 0? As I see we expose only methods, so we should use and check
DISPATCH_METHOD.

[Eric, 2014/08/14 14:29:53]

I changed this in the test, but the larger problem is that the implementation of
IDispatch under test doesn't check the flag at all. 

That's only a minor problem, because our JavaScript code doesn't try to
manipulate properties on the "Settings" object, but I'm not going to fix it
here; it's beyond the scope of the present unit of work.

+    ASSERT_NE(S_OK, h);
+    // The old version returns a nonstandard error code.
+    if (h == DISP_E_BADINDEX)
+    {
+      return;
+    }
+    EXPECT_EQ(DISP_E_MEMBERNOTFOUND, h);
+  }
+}
+
+TEST(CPluginUserSettings_Invoke_Test, invalid_dispatch_id_underflow)

[sergei, 2014/08/14 11:37:26]

I prefer more descriptive test names.

[Eric, 2014/08/14 14:29:53]

I added comments. If the test fails, the first thing you have to do is to look
at the test code.

I find the test names adequately descriptive.

+{
+  invoke_invalid_dispatch_id(-1);
+}
+
+TEST(CPluginUserSettings_Invoke_Test, invalid_dispatch_id_overflow)
+{
+  invoke_invalid_dispatch_id(13);
+}