Force U.S. English keyboard layout for TextfieldTest.KeysWithModifiersTest

chrome/test/chromedriver/keycode_text_conversion_unittest.cc

 // Copyright (c) 2013 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 <string>
 
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "chrome/test/chromedriver/chrome/ui_events.h"
 #include "chrome/test/chromedriver/keycode_text_conversion.h"
-#include "chrome/test/chromedriver/test_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/events/keycodes/keyboard_codes.h"
+#include "ui/events/test/keyboard_layout.h"
 
 namespace {
 
 void CheckCharToKeyCode16(base::char16 character, ui::KeyboardCode key_code,
                           int modifiers) {
   ui::KeyboardCode actual_key_code = ui::VKEY_UNKNOWN;
   int actual_modifiers = 0;
   std::string error_msg;
   EXPECT_TRUE(ConvertCharToKeyCode(
       character, &actual_key_code, &actual_modifiers, &error_msg));
@@ skipping 95 matching lines @@
 
 #if (defined(OS_LINUX) && !defined(OS_CHROMEOS)) || defined(OS_MACOSX)
 // Not implemented on Linux.
 // Fails if German layout is not installed on Mac.
 #define MAYBE_NonShiftModifiers DISABLED_NonShiftModifiers
 #else
 #define MAYBE_NonShiftModifiers NonShiftModifiers
 #endif
 
 TEST(KeycodeTextConversionTest, MAYBE_NonShiftModifiers) {
-  RestoreKeyboardLayoutOnDestruct restore;
+  ui::ScopedKeyboardLayout keyboard_layout(ui::KEYBOARD_LAYOUT_GERMAN);
 #if defined(OS_WIN)
-  ASSERT_TRUE(SwitchKeyboardLayout("00000407"));  // german
   int ctrl_and_alt = kControlKeyModifierMask | kAltKeyModifierMask;
   CheckCharToKeyCode('@', ui::VKEY_Q, ctrl_and_alt);
   EXPECT_EQ("@", ConvertKeyCodeToTextNoError(ui::VKEY_Q, ctrl_and_alt));
 #elif defined(OS_MACOSX)
-  ASSERT_TRUE(SwitchKeyboardLayout("com.apple.keylayout.German"));
   EXPECT_EQ("@", ConvertKeyCodeToTextNoError(
       ui::VKEY_L, kAltKeyModifierMask));
 #endif
 }
 
 #if (defined(OS_LINUX) && !defined(OS_CHROMEOS)) || defined(OS_MACOSX)
 // Not implemented on Linux.
 // Fails if German layout is not installed on Mac.
 #define MAYBE_NonEnglish DISABLED_NonEnglish
 #else
 #define MAYBE_NonEnglish NonEnglish
 #endif
 
 TEST(KeycodeTextConversionTest, MAYBE_NonEnglish) {
-  RestoreKeyboardLayoutOnDestruct restore;
 #if defined(OS_WIN)
-  ASSERT_TRUE(SwitchKeyboardLayout("00000408"));  // greek
-  CheckCharToKeyCode(';', ui::VKEY_Q, 0);
-  EXPECT_EQ(";", ConvertKeyCodeToTextNoError(ui::VKEY_Q, 0));
-  // Regression test for chromedriver bug #405.
-  ASSERT_TRUE(SwitchKeyboardLayout("00000419"));  // russian
-  CheckCharToKeyCode(L'\u0438', ui::VKEY_B, 0);
-  EXPECT_EQ(base::UTF16ToUTF8(L"\u0438"),
-            ConvertKeyCodeToTextNoError(ui::VKEY_B, 0));
+  {
+    ui::ScopedKeyboardLayout greek_layout(ui::KEYBOARD_LAYOUT_GREEK);
+    CheckCharToKeyCode(';', ui::VKEY_Q, 0);
+    EXPECT_EQ(";", ConvertKeyCodeToTextNoError(ui::VKEY_Q, 0));
+  }
+  {
+    // Regression test for chromedriver bug #405.
+    ui::ScopedKeyboardLayout russian_layout(ui::KEYBOARD_LAYOUT_RUSSIAN);
+    CheckCharToKeyCode(L'\u0438', ui::VKEY_B, 0);
+    EXPECT_EQ(base::UTF16ToUTF8(L"\u0438"),
+              ConvertKeyCodeToTextNoError(ui::VKEY_B, 0));
+  }

[Peter Kasting, 2016/08/26 18:54:33]

In principle, is there a reason why these tests would be OS-specific?  Like, if
we supported the Greek and Russian layouts on Mac, would it make sense to test
this functionality there as well?

Because if so maybe the right answer is to expand the supported layouts on these
platforms and then reduce the #ifdefing in the test files.

[Tomasz Moniuszko, 2016/08/31 15:29:42]

I tested Greek and Russian keyboard layouts on Mac. Pressing Q key gives ';'
character with Greek and pressing B key gives 'и' character with Russian just
like on Windows. Similarly pressing Y key on Windows with German keyboard layout
gives 'z' character. I did both tests using physical US QWERTY keyboard.

Unfortunately Y key test here fails on Windows when I remove #ifdefs. I'm not
sure why. I guess Y key on QWERTZ keyboard sends Y virtual key.

[Peter Kasting, 2016/08/31 21:16:15]

That sounds like those tests should be enabled on Mac then?
I'd like to understand why the test fails if the behavior it's trying to test is
the behavior you see in actual usage.  This makes me worry that we're missing
something here.

[chongz, 2016/09/03 00:44:17]

The following comments are not verified, please remind me if I'm wrong.

Q1. Why is the last test case different from the first 2?
I think the reason is German layout is different from Greek and Russian, where:
  * Greek and Russian layout's character set is very different from English
letters, so they are just using QWERTY layout for VKEYs instead of trying to
match characters. (I don't have access to Windows right now and cannot verify)
  * On German layout most English letters are available, so just VKEY_Y and
VKEY_Z was swapped.


Q2. How to make the last test case work on Windows?
I believe |CheckCharToKeyCode('z', ui::VKEY_Z, 0);| would work.


Q3. Why the last test case would work on mac OS?
* I believe it only works on QWERTY physical keyboard with German system layout.
It seems to me that the Mac's version of |CheckCharToKeyCode()| is actually
using scan code rather than VKEY to do the mapping.

e.g. On QWERTY physical keyboard with German system layout:
  * The scan code for key labeled as 'Y' is still 'Y'
  * The VKEY for key labeled as 'Y' becomes 'Z'
  * The character produced by scan code 'Y' would be 'z'.

Also see how we are using [NSEvent keyCode] to get DomCode (which is essentially
scan code):
https://cs.chromium.org/chromium/src/ui/events/keycodes/keyboard_code_convers...

[Tomasz Moniuszko, 2016/09/07 11:19:01]

I think this is the right answer. Windows system uses a predefined set of
virtual-key codes:
https://msdn.microsoft.com/en-us/library/windows/desktop/dd375731(v=vs.85).aspx
Only codes for characters from Latin script are available. There are no codes
for Greek or Cyrillic characters.

I tested Greek and Russian keyboards: virtual-key codes match QWERTY layout.
I also tested US Dvorak keyboard: virtual-key codes match key labels here (just
like in case of QWERTZ keyboard).

 #elif defined(OS_MACOSX)
-  ASSERT_TRUE(SwitchKeyboardLayout("com.apple.keylayout.German"));
+  ui::ScopedKeyboardLayout german_layout(ui::KEYBOARD_LAYOUT_GERMAN);
   CheckCharToKeyCode('z', ui::VKEY_Y, 0);
   EXPECT_EQ("z", ConvertKeyCodeToTextNoError(ui::VKEY_Y, 0));
 #endif
 }