[WSLC] Add 'wslc version' subcommand (#14547)

* [WSLC] Add 'wslc version' subcommand

Adds a 'version' subcommand to the WSLC CLI as an alternative to the
existing '--version' flag, following the subcommand pattern used by
other WSLC commands. Includes unit tests for command structure and
command-line parsing.

Co-authored-by: Pooja Trivedi <trivedipooja@microsoft.com>
Co-Authored-By: Claude Sonnet 4.6

* [WSLC] Fix E2E help/invalid-command tests after version subcommand addition

Update expected help output in WSLCE2EGlobalTests to include the newly
added 'version' subcommand, fixing WSLCE2E_HelpCommand and
WSLCE2E_InvalidCommand_DisplaysErrorMessage test failures.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* [WSLC] Add E2E version command test and strengthen unit test

- Add WSLCE2E_VersionCommand E2E test in WSLCE2EGlobalTests verifying
  stdout, empty stderr, and exit code for 'wslc version'
- Add assertion to VersionCommand_HasNoArguments unit test to verify
  only the auto-added --help argument is present

Authored-By: Pooja Trivedi <trivedipooja@microsoft.com>
Co-Authored-By: Claude Sonnet 4.6

* Mark 'context' as UNREFERENCED_PARAMETER in
VersionCommand::ExecuteInternal to avoid build issues

* Address PR feedback on wslc version command

- Use Localization::WSLCCLI_VersionDesc/LongDesc instead of hard-coded strings; add entries to en-US Resources.resw
- Centralize version printing in VersionCommand::PrintVersion(); reuse from RootCommand --version flag
- Drop 'v' prefix from version output per OneBlue's feedback
- Add 'version' entry to E2E GetAvailableCommands() to fix WSLCE2E_HelpCommand and WSLCE2E_InvalidCommand_DisplaysErrorMessage

Co-Authored-By: Pooja Trivedi

* Fix build: add missing using namespace wsl::shared

Localization::WSLCCLI_VersionDesc() and WSLCCLI_VersionLongDesc() live in
wsl::shared::Localization. Without this using directive the compiler cannot
resolve the unqualified Localization:: references in VersionCommand.cpp.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Pooja Trivedi <trivedipooja@microsoft.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 4 people

localization/strings/en-US/Resources.resw

@@ -2313,6 +2313,12 @@ On first run, creates the file with all settings commented out at their defaults
   <data name="WSLCCLI_SettingsResetConfirm" xml:space="preserve">
     <value>Settings reset to defaults.</value>
   </data>
+  <data name="WSLCCLI_VersionDesc" xml:space="preserve">
+    <value>Show version information.</value>
+  </data>
+  <data name="WSLCCLI_VersionLongDesc" xml:space="preserve">
+    <value>Show version information for this tool.</value>
+  </data>
   <data name="WSLCCLI_AllArgDescription" xml:space="preserve">
     <value>Show all regardless of state.</value>
   </data>

src/windows/wslc/commands/RootCommand.cpp

@@ -18,6 +18,7 @@ Module Name:
 #include "ImageCommand.h"
 #include "SessionCommand.h"
 #include "SettingsCommand.h"
+#include "VersionCommand.h"
 
 using namespace wsl::windows::wslc::execution;
 using namespace wsl::shared;
@@ -47,6 +48,7 @@ std::vector<std::unique_ptr<Command>> RootCommand::GetCommands() const
     commands.push_back(std::make_unique<ImageSaveCommand>(FullName()));
     commands.push_back(std::make_unique<ContainerStartCommand>(FullName()));
     commands.push_back(std::make_unique<ContainerStopCommand>(FullName()));
+    commands.push_back(std::make_unique<VersionCommand>(FullName()));
     return commands;
 }
 
@@ -71,7 +73,7 @@ void RootCommand::ExecuteInternal(CLIExecutionContext& context) const
 {
     if (context.Args.Contains(ArgType::Version))
     {
-        wsl::windows::common::wslutil::PrintMessage(std::format(L"{} v{}", s_ExecutableName, WSL_PACKAGE_VERSION));
+        VersionCommand::PrintVersion();
         return;
     }
 

src/windows/wslc/commands/VersionCommand.cpp

@@ -0,0 +1,40 @@
+/*++
+
+Copyright (c) Microsoft. All rights reserved.
+
+Module Name:
+
+    VersionCommand.cpp
+
+Abstract:
+
+    Implementation of the version command.
+
+--*/
+#include "VersionCommand.h"
+
+using namespace wsl::shared;
+using namespace wsl::windows::wslc::execution;
+
+namespace wsl::windows::wslc {
+std::wstring VersionCommand::ShortDescription() const
+{
+    return Localization::WSLCCLI_VersionDesc();
+}
+
+std::wstring VersionCommand::LongDescription() const
+{
+    return Localization::WSLCCLI_VersionLongDesc();
+}
+
+void VersionCommand::PrintVersion()
+{
+    wsl::windows::common::wslutil::PrintMessage(std::format(L"{} {}", s_ExecutableName, WSL_PACKAGE_VERSION));
+}
+
+void VersionCommand::ExecuteInternal(CLIExecutionContext& context) const
+{
+    UNREFERENCED_PARAMETER(context);
+    PrintVersion();
+}
+} // namespace wsl::windows::wslc

src/windows/wslc/commands/VersionCommand.h

@@ -0,0 +1,31 @@
+/*++
+
+Copyright (c) Microsoft. All rights reserved.
+
+Module Name:
+
+    VersionCommand.h
+
+Abstract:
+
+    Declaration of the VersionCommand.
+
+--*/
+#pragma once
+#include "Command.h"
+
+namespace wsl::windows::wslc {
+struct VersionCommand final : public Command
+{
+    constexpr static std::wstring_view CommandName = L"version";
+    VersionCommand(const std::wstring& parent) : Command(CommandName, parent)
+    {
+    }
+    static void PrintVersion();
+    std::wstring ShortDescription() const override;
+    std::wstring LongDescription() const override;
+
+protected:
+    void ExecuteInternal(CLIExecutionContext& context) const override;
+};
+} // namespace wsl::windows::wslc

test/windows/wslc/CommandLineTestCases.h

@@ -125,6 +125,10 @@ COMMAND_LINE_TEST_CASE(L"image list -q", L"list", true)
 COMMAND_LINE_TEST_CASE(L"image pull ubuntu", L"pull", true)
 COMMAND_LINE_TEST_CASE(L"pull ubuntu", L"pull", true)
 
+// Version command tests
+COMMAND_LINE_TEST_CASE(L"version", L"version", true)
+COMMAND_LINE_TEST_CASE(L"version --help", L"version", true)
+COMMAND_LINE_TEST_CASE(L"version extraarg", L"version", false)
 // Settings command
 COMMAND_LINE_TEST_CASE(L"settings", L"settings", true)
 COMMAND_LINE_TEST_CASE(L"settings reset", L"reset", true)

test/windows/wslc/WSLCCLICommandUnitTests.cpp

@@ -20,6 +20,7 @@ Module Name:
 #include "RootCommand.h"
 #include "ContainerCommand.h"
 #include "SessionCommand.h"
+#include "VersionCommand.h"
 
 using namespace wsl::windows::wslc;
 using namespace WSLCTestHelpers;
@@ -126,6 +127,48 @@ class WSLCCLICommandUnitTests
             VERIFY_IS_NOT_NULL(subcmd.get());
         }
     }
+
+    // Test: Verify VersionCommand has the correct name
+    TEST_METHOD(VersionCommand_HasCorrectName)
+    {
+        auto cmd = VersionCommand(L"wslc");
+        VERIFY_ARE_EQUAL(std::wstring_view(L"version"), cmd.Name());
+    }
+
+    // Test: Verify VersionCommand has no subcommands
+    TEST_METHOD(VersionCommand_HasNoSubcommands)
+    {
+        auto cmd = VersionCommand(L"wslc");
+        VERIFY_ARE_EQUAL(0u, cmd.GetCommands().size());
+    }
+
+    // Test: Verify VersionCommand has no arguments (only the auto-added --help)
+    TEST_METHOD(VersionCommand_HasNoArguments)
+    {
+        auto cmd = VersionCommand(L"wslc");
+        VERIFY_ARE_EQUAL(0u, cmd.GetArguments().size());
+        // Test out that auto added help command is the only one
+        VERIFY_ARE_EQUAL(1u, cmd.GetAllArguments().size());
+    }
+
+    // Test: Verify RootCommand contains VersionCommand as a subcommand
+    TEST_METHOD(RootCommand_ContainsVersionCommand)
+    {
+        auto root = RootCommand();
+        auto subcommands = root.GetCommands();
+
+        bool found = false;
+        for (const auto& subcmd : subcommands)
+        {
+            if (subcmd->Name() == VersionCommand::CommandName)
+            {
+                found = true;
+                break;
+            }
+        }
+
+        VERIFY_IS_TRUE(found, L"RootCommand should contain VersionCommand");
+    }
 };
 
 } // namespace WSLCCLICommandUnitTests

test/windows/wslc/e2e/WSLCE2EGlobalTests.cpp

@@ -51,6 +51,11 @@ class WSLCE2EGlobalTests
         RunWslcAndVerify(L"INVALID_CMD", {.Stdout = GetHelpMessage(), .Stderr = L"Unrecognized command: 'INVALID_CMD'\r\n", .ExitCode = 1});
     }
 
+    TEST_METHOD(WSLCE2E_VersionCommand)
+    {
+        WSL2_TEST_ONLY();
+        RunWslcAndVerify(L"version", {.Stdout = GetVersionMessage(), .Stderr = L"", .ExitCode = 0});
+    }
     TEST_METHOD(WSLCE2E_Session_DefaultElevated)
     {
         WSL2_TEST_ONLY();
@@ -400,6 +405,11 @@ class WSLCE2EGlobalTests
         return output.str();
     }
 
+    std::wstring GetVersionMessage() const
+    {
+        return std::format(L"wslc {}\r\n", WSL_PACKAGE_VERSION);
+    }
+
     std::wstring GetDescription() const
     {
         return L"WSLC is the Windows Subsystem for Linux Container CLI tool. It enables management and interaction with WSL "
@@ -435,6 +445,7 @@ class WSLCE2EGlobalTests
             {L"save", Localization::WSLCCLI_ImageSaveDesc()},
             {L"start", Localization::WSLCCLI_ContainerStartDesc()},
             {L"stop", Localization::WSLCCLI_ContainerStopDesc()},
+            {L"version", Localization::WSLCCLI_VersionDesc()},
         };
 
         size_t maxLen = 0;