Add persistent output locale override setting

doc/ReleaseNotes.md

@@ -1,6 +1,12 @@
 ## New in v1.29
 
-Nothing yet.
+## New Features
+
+### Output locale override
+
+Added a persistent `output.locale` setting to override winget interface language using a BCP47 tag.
+
+Usage: add `"output": { "locale": "de-DE" }` to `settings.json`.
 
 ## Bug Fixes
 

doc/Settings.md

@@ -388,6 +388,23 @@ The `interactivity` settings control whether winget may show interactive prompts
 
 If set to true, the `interactivity.disable` setting will prevent any interactive prompt from being shown.
 
+## Output
+
+The `output` settings control how winget presents CLI output.
+
+### locale
+
+The `locale` setting overrides winget interface language by BCP47 tag (for example, `en-US`). If this setting is missing or invalid, winget uses the default Windows globalization behavior.
+
+> [!NOTE]
+> This only affects winget interface strings. It does not change package metadata localization or installer selection behavior.
+
+```json
+    "output": {
+        "locale": "en-US"
+    },
+```
+
 ## Experimental Features
 
 To allow work to be done and distributed to early adopters for feedback, settings can be used to enable "experimental" features.

doc/windows/package-manager/winget/settings.md

@@ -98,6 +98,25 @@ The `locale` behavior affects the choice of installer based on installer locale.
     },
 ```
 
+### Output
+
+The `output` settings affect winget interface output behavior.
+
+#### locale
+
+The `locale` setting overrides winget interface language using a supported locale value. If not specified, winget uses the default Windows globalization behavior.
+
+Supported values: `en-US`, `de-DE`, `es-ES`, `fr-FR`, `it-IT`, `ja-JP`, `ko-KR`, `pt-BR`, `ru-RU`, `zh-CN`, `zh-TW`.
+
+> [!NOTE]
+> This setting only affects winget interface strings and does not affect package metadata localization or installer locale selection.
+
+```json
+    "output": {
+        "locale": "en-US"
+    },
+```
+
 ### Telemetry
 
 The `telemetry` settings control whether winget writes ETW events that may be sent to Microsoft on a default installation of Windows.
@@ -133,4 +152,3 @@ The `downloader` setting controls which code is used when downloading packages.
 ## Enabling Experimental features
 
 To discover which experimental features are available, go to [https://aka.ms/winget-settings](https://aka.ms/winget-settings) where you can see the experimental features available to you.
-

schemas/JSON/settings/settings.schema.0.2.json

@@ -378,6 +378,23 @@
             "descending"
           ],
           "default": "ascending"
+        },
+        "locale": {
+          "description": "Overrides winget interface output language using a supported locale",
+          "type": "string",
+          "enum": [
+            "en-US",
+            "de-DE",
+            "es-ES",
+            "fr-FR",
+            "it-IT",
+            "ja-JP",
+            "ko-KR",
+            "pt-BR",
+            "ru-RU",
+            "zh-CN",
+            "zh-TW"
+          ]
         }
       }
     }

src/AppInstallerCLICore/Core.cpp

@@ -10,6 +10,7 @@
 #include "COMContext.h"
 #include <AppInstallerFileLogger.h>
 #include <winget/OutputDebugStringLogger.h>
+#include <winrt/Windows.Globalization.h>
 #include "Public/ShutdownMonitoring.h"
 
 #ifndef AICLI_DISABLE_TEST_HOOKS
@@ -78,6 +79,25 @@ namespace AppInstaller::CLI
             main.Wait = WaitOnMainWaitEvent;
             ShutdownMonitoring::ServerShutdownSynchronization::AddComponent(main);
         }
+
+        std::string ApplyOutputLocaleOverride()
+        {
+            std::string localeTag{ Settings::User().Get<Settings::Setting::OutputLocale>() };
+
+            try
+            {
+                // Always apply the setting value, including empty string, to clear a persisted override from
+                // previous sessions. PrimaryLanguageOverride is package-scoped and persists across sessions.
+                winrt::Windows::Globalization::ApplicationLanguages::PrimaryLanguageOverride(Utility::ConvertToUTF16(localeTag));
+            }
+            catch (const winrt::hresult_error& hre)
+            {
+                AICLI_LOG(CLI, Warning, << "Failed to apply output locale override for " << localeTag << ". HRESULT: 0x" << Logging::SetHRFormat << hre.code());
+                return {};
+            }
+
+            return localeTag;
+        }
     }
 
     int CoreMain(int argc, wchar_t const** argv) try
@@ -89,7 +109,6 @@ namespace AppInstaller::CLI
         std::signal(SIGABRT, abort_signal_handler);
 
         init_apartment();
-
 #ifndef AICLI_DISABLE_TEST_HOOKS
         // We have to do this here so the auto minidump config initialization gets caught
         Logging::OutputDebugStringLogger::Add();
@@ -120,6 +139,12 @@ namespace AppInstaller::CLI
         Logging::OutputDebugStringLogger::Remove();
         Logging::EnableWilFailureTelemetry();
 
+        std::string outputLocaleOverride = ApplyOutputLocaleOverride();
+        if (!outputLocaleOverride.empty())
+        {
+            AICLI_LOG(CLI, Info, << "Applied output locale override from settings: " << outputLocaleOverride);
+        }
+
         // Set output to UTF8
         ConsoleOutputCPRestore utf8CP(CP_UTF8);
 

src/AppInstallerCLIPackage/AppInstallerCLIPackage.wapproj

@@ -187,15 +187,25 @@
       <SubType>Designer</SubType>
     </PRIResource>
     <PRIResource Include="shared\strings\de-DE\winget.resw" Condition="Exists('shared\strings\de-DE\winget.resw')" />
+    <PRIResource Include="..\..\Localization\Resources\de-DE\winget.resw" Condition="!Exists('shared\strings\de-DE\winget.resw') and Exists('..\..\Localization\Resources\de-DE\winget.resw')" />
     <PRIResource Include="shared\strings\es-ES\winget.resw" Condition="Exists('shared\strings\es-ES\winget.resw')" />
+    <PRIResource Include="..\..\Localization\Resources\es-ES\winget.resw" Condition="!Exists('shared\strings\es-ES\winget.resw') and Exists('..\..\Localization\Resources\es-ES\winget.resw')" />
     <PRIResource Include="shared\strings\fr-FR\winget.resw" Condition="Exists('shared\strings\fr-FR\winget.resw')" />
+    <PRIResource Include="..\..\Localization\Resources\fr-FR\winget.resw" Condition="!Exists('shared\strings\fr-FR\winget.resw') and Exists('..\..\Localization\Resources\fr-FR\winget.resw')" />
     <PRIResource Include="shared\strings\it-IT\winget.resw" Condition="Exists('shared\strings\it-IT\winget.resw')" />
+    <PRIResource Include="..\..\Localization\Resources\it-IT\winget.resw" Condition="!Exists('shared\strings\it-IT\winget.resw') and Exists('..\..\Localization\Resources\it-IT\winget.resw')" />
     <PRIResource Include="shared\strings\ja-JP\winget.resw" Condition="Exists('shared\strings\ja-JP\winget.resw')" />
+    <PRIResource Include="..\..\Localization\Resources\ja-JP\winget.resw" Condition="!Exists('shared\strings\ja-JP\winget.resw') and Exists('..\..\Localization\Resources\ja-JP\winget.resw')" />
     <PRIResource Include="shared\strings\ko-KR\winget.resw" Condition="Exists('shared\strings\ko-KR\winget.resw')" />
+    <PRIResource Include="..\..\Localization\Resources\ko-KR\winget.resw" Condition="!Exists('shared\strings\ko-KR\winget.resw') and Exists('..\..\Localization\Resources\ko-KR\winget.resw')" />
     <PRIResource Include="shared\strings\pt-BR\winget.resw" Condition="Exists('shared\strings\pt-BR\winget.resw')" />
+    <PRIResource Include="..\..\Localization\Resources\pt-BR\winget.resw" Condition="!Exists('shared\strings\pt-BR\winget.resw') and Exists('..\..\Localization\Resources\pt-BR\winget.resw')" />
     <PRIResource Include="shared\strings\ru-RU\winget.resw" Condition="Exists('shared\strings\ru-RU\winget.resw')" />
+    <PRIResource Include="..\..\Localization\Resources\ru-RU\winget.resw" Condition="!Exists('shared\strings\ru-RU\winget.resw') and Exists('..\..\Localization\Resources\ru-RU\winget.resw')" />
     <PRIResource Include="shared\strings\zh-CN\winget.resw" Condition="Exists('shared\strings\zh-CN\winget.resw')" />
+    <PRIResource Include="..\..\Localization\Resources\zh-CN\winget.resw" Condition="!Exists('shared\strings\zh-CN\winget.resw') and Exists('..\..\Localization\Resources\zh-CN\winget.resw')" />
     <PRIResource Include="shared\strings\zh-TW\winget.resw" Condition="Exists('shared\strings\zh-TW\winget.resw')" />
+    <PRIResource Include="..\..\Localization\Resources\zh-TW\winget.resw" Condition="!Exists('shared\strings\zh-TW\winget.resw') and Exists('..\..\Localization\Resources\zh-TW\winget.resw')" />
     <PRIResource Include="Shared\Strings\en-us\Resources.resw" />
   </ItemGroup>
   <ItemGroup>

src/AppInstallerCLITests/UserSettings.cpp

@@ -925,6 +925,64 @@ TEST_CASE("SettingOutputSortDirection", "[settings]")
     }
 }
 
+TEST_CASE("SettingOutputLocale", "[settings]")
+{
+    auto again = DeleteUserSettingsFiles();
+
+    SECTION("Default value")
+    {
+        UserSettingsTest userSettingTest;
+
+        REQUIRE(userSettingTest.Get<Setting::OutputLocale>().empty());
+        REQUIRE(userSettingTest.GetWarnings().size() == 0);
+    }
+    SECTION("Valid locale")
+    {
+        std::string_view json = R"({ "output": { "locale": "en-US" } })";
+        SetSetting(Stream::PrimaryUserSettings, json);
+        UserSettingsTest userSettingTest;
+
+        REQUIRE(userSettingTest.Get<Setting::OutputLocale>() == "en-US"sv);
+        REQUIRE(userSettingTest.GetWarnings().size() == 0);
+    }
+    SECTION("Case insensitive locale")
+    {
+        std::string_view json = R"({ "output": { "locale": "EN-us" } })";
+        SetSetting(Stream::PrimaryUserSettings, json);
+        UserSettingsTest userSettingTest;
+
+        REQUIRE(userSettingTest.Get<Setting::OutputLocale>() == "en-US"sv);
+        REQUIRE(userSettingTest.GetWarnings().size() == 0);
+    }
+    SECTION("Unsupported locale")
+    {
+        std::string_view json = R"({ "output": { "locale": "el-GR" } })";
+        SetSetting(Stream::PrimaryUserSettings, json);
+        UserSettingsTest userSettingTest;
+
+        REQUIRE(userSettingTest.Get<Setting::OutputLocale>().empty());
+        REQUIRE(userSettingTest.GetWarnings().size() == 1);
+    }
+    SECTION("Invalid locale")
+    {
+        std::string_view json = R"({ "output": { "locale": "en_US.UTF-8" } })";
+        SetSetting(Stream::PrimaryUserSettings, json);
+        UserSettingsTest userSettingTest;
+
+        REQUIRE(userSettingTest.Get<Setting::OutputLocale>().empty());
+        REQUIRE(userSettingTest.GetWarnings().size() == 1);
+    }
+    SECTION("Wrong type")
+    {
+        std::string_view json = R"({ "output": { "locale": ["en-US"] } })";
+        SetSetting(Stream::PrimaryUserSettings, json);
+        UserSettingsTest userSettingTest;
+
+        REQUIRE(userSettingTest.Get<Setting::OutputLocale>().empty());
+        REQUIRE(userSettingTest.GetWarnings().size() == 1);
+    }
+}
+
 TEST_CASE("ConvertToSortField", "[settings]")
 {
     SECTION("Valid values - lowercase")

src/AppInstallerCommonCore/Public/winget/UserSettings.h

@@ -144,6 +144,7 @@ namespace AppInstaller::Settings
         // Output behavior
         OutputSortOrder,
         OutputSortDirection,
+        OutputLocale,
 #ifndef AICLI_DISABLE_TEST_HOOKS
         // Debug
         EnableSelfInitiatedMinidump,
@@ -242,6 +243,7 @@ namespace AppInstaller::Settings
         // Output behavior
         SETTINGMAPPING_SPECIALIZATION(Setting::OutputSortOrder, std::vector<std::string>, std::vector<SortField>, std::vector<SortField>{}, ".output.sortOrder"sv);
         SETTINGMAPPING_SPECIALIZATION(Setting::OutputSortDirection, std::string, SortDirection, SortDirection::Ascending, ".output.sortDirection"sv);
+        SETTINGMAPPING_SPECIALIZATION(Setting::OutputLocale, std::string, std::string, std::string{}, ".output.locale"sv);
 
         // Used to deduce the SettingVariant type; making a variant that includes std::monostate and all SettingMapping types.
         template <size_t... I>

src/AppInstallerCommonCore/UserSettings.cpp

@@ -12,6 +12,8 @@
 #include "AppInstallerArchitecture.h"
 #include "winget/Locale.h"
 
+#include <array>
+
 namespace AppInstaller::Settings
 {
     using namespace std::string_view_literals;
@@ -213,6 +215,34 @@ namespace AppInstaller::Settings
 
             return path;
         }
+
+        static constexpr std::array<std::string_view, 11> s_supportedOutputLocales =
+        {
+            "en-US"sv,
+            "de-DE"sv,
+            "es-ES"sv,
+            "fr-FR"sv,
+            "it-IT"sv,
+            "ja-JP"sv,
+            "ko-KR"sv,
+            "pt-BR"sv,
+            "ru-RU"sv,
+            "zh-CN"sv,
+            "zh-TW"sv,
+        };
+
+        std::optional<std::string_view> NormalizeSupportedLocale(std::string_view localeTag)
+        {
+            for (const auto& supportedLocale : s_supportedOutputLocales)
+            {
+                if (Utility::CaseInsensitiveEquals(localeTag, supportedLocale))
+                {
+                    return supportedLocale;
+                }
+            }
+
+            return {};
+        }
     }
 
     std::optional<SortField> ConvertToSortField(std::string_view value)
@@ -561,6 +591,17 @@ namespace AppInstaller::Settings
 
             return {};
         }
+
+        WINGET_VALIDATE_SIGNATURE(OutputLocale)
+        {
+            auto normalizedLocale = NormalizeSupportedLocale(value);
+            if (normalizedLocale)
+            {
+                return std::string{ normalizedLocale.value() };
+            }
+
+            return {};
+        }
     }
 
 #ifndef AICLI_DISABLE_TEST_HOOKS