Add splitMode to the args for split-pane (as -D for duplicate)

src/cascadia/LocalTests_TerminalApp/CommandlineTest.cpp

@@ -680,6 +680,7 @@ namespace TerminalAppLocalTests
             auto myArgs = actionAndArgs.Args().try_as<SplitPaneArgs>();
             VERIFY_IS_NOT_NULL(myArgs);
             VERIFY_ARE_EQUAL(SplitState::Automatic, myArgs.SplitStyle());
+            VERIFY_ARE_EQUAL(SplitType::Manual, myArgs.SplitMode());
             VERIFY_IS_NOT_NULL(myArgs.TerminalArgs());
         }
         {
@@ -699,6 +700,7 @@ namespace TerminalAppLocalTests
             auto myArgs = actionAndArgs.Args().try_as<SplitPaneArgs>();
             VERIFY_IS_NOT_NULL(myArgs);
             VERIFY_ARE_EQUAL(SplitState::Horizontal, myArgs.SplitStyle());
+            VERIFY_ARE_EQUAL(SplitType::Manual, myArgs.SplitMode());
             VERIFY_IS_NOT_NULL(myArgs.TerminalArgs());
         }
         {
@@ -720,6 +722,28 @@ namespace TerminalAppLocalTests
             auto myArgs = actionAndArgs.Args().try_as<SplitPaneArgs>();
             VERIFY_IS_NOT_NULL(myArgs);
             VERIFY_ARE_EQUAL(SplitState::Vertical, myArgs.SplitStyle());
+            VERIFY_ARE_EQUAL(SplitType::Manual, myArgs.SplitMode());
+            VERIFY_IS_NOT_NULL(myArgs.TerminalArgs());
+        }
+        {
+            AppCommandlineArgs appArgs{};
+            std::vector<const wchar_t*> rawCommands{ L"wt.exe", subcommand, L"-D" };
+            auto commandlines = AppCommandlineArgs::BuildCommands(rawCommands);
+            VERIFY_ARE_EQUAL(1u, commandlines.size());
+            _buildCommandlinesHelper(appArgs, 1u, rawCommands);
+
+            VERIFY_ARE_EQUAL(2u, appArgs._startupActions.size());
+
+            // The first action is going to always be a new-tab action
+            VERIFY_ARE_EQUAL(ShortcutAction::NewTab, appArgs._startupActions.at(0).Action());
+
+            // The one we actually want to test here is the SplitPane action we created
+            auto actionAndArgs = appArgs._startupActions.at(1);
+            VERIFY_ARE_EQUAL(ShortcutAction::SplitPane, actionAndArgs.Action());
+            VERIFY_IS_NOT_NULL(actionAndArgs.Args());
+            auto myArgs = actionAndArgs.Args().try_as<SplitPaneArgs>();
+            VERIFY_IS_NOT_NULL(myArgs);
+            VERIFY_ARE_EQUAL(SplitType::Duplicate, myArgs.SplitMode());
             VERIFY_IS_NOT_NULL(myArgs.TerminalArgs());
         }
         {

src/cascadia/TerminalApp/AppCommandlineArgs.cpp

@@ -255,6 +255,10 @@ void AppCommandlineArgs::_buildSplitPaneParser()
         auto* sizeOpt = subcommand.subcommand->add_option("-s,--size",
                                                           _splitPaneSize,
                                                           RS_A(L"CmdSplitPaneSizeArgDesc"));
+
+        subcommand._duplicateOption = subcommand.subcommand->add_flag("-D,--duplicate",
+                                                                      _splitDuplicate,
+                                                                      RS_A(L"CmdSplitPaneDuplicateArgDesc"));
         sizeOpt->check(CLI::Range(0.01f, 0.99f));
 
         // When ParseCommand is called, if this subcommand was provided, this
@@ -283,7 +287,8 @@ void AppCommandlineArgs::_buildSplitPaneParser()
                     style = SplitState::Vertical;
                 }
             }
-            SplitPaneArgs args{ style, _splitPaneSize, terminalArgs };
+            const auto splitMode{ subcommand._duplicateOption && _splitDuplicate ? SplitType::Duplicate : SplitType::Manual };
+            SplitPaneArgs args{ splitMode, style, _splitPaneSize, terminalArgs };
             splitPaneActionAndArgs.Args(args);
             _startupActions.push_back(splitPaneActionAndArgs);
         });
@@ -537,6 +542,7 @@ void AppCommandlineArgs::_resetStateToDefault()
     _splitVertical = false;
     _splitHorizontal = false;
     _splitPaneSize = 0.5f;
+    _splitDuplicate = false;
 
     _focusTabIndex = -1;
     _focusNextTab = false;

src/cascadia/TerminalApp/AppCommandlineArgs.h

@@ -68,6 +68,7 @@ class TerminalApp::AppCommandlineArgs final
     {
         CLI::Option* _horizontalOption;
         CLI::Option* _verticalOption;
+        CLI::Option* _duplicateOption;
     };
 
     // --- Subcommands ---
@@ -95,6 +96,7 @@ class TerminalApp::AppCommandlineArgs final
 
     bool _splitVertical{ false };
     bool _splitHorizontal{ false };
+    bool _splitDuplicate{ false };
     float _splitPaneSize{ 0.5f };
 
     int _focusTabIndex{ -1 };

src/cascadia/TerminalApp/Resources/en-US/Resources.resw

@@ -308,6 +308,9 @@
   <data name="CmdSplitPaneVerticalArgDesc" xml:space="preserve">
     <value>Create the new pane as a vertical split (think [|])</value>
   </data>
+  <data name="CmdSplitPaneDuplicateArgDesc" xml:space="preserve">
+    <value>Create the new pane by duplicating the profile of the focused pane</value>
+  </data>
   <data name="CmdStartingDirArgDesc" xml:space="preserve">
     <value>Open in the given directory instead of the profile's set "startingDirectory"</value>
     <comment>{Locked="\"startingDirectory\""}</comment>

src/cascadia/TerminalSettingsModel/ActionArgs.h

@@ -389,6 +389,11 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
     struct SplitPaneArgs : public SplitPaneArgsT<SplitPaneArgs>
     {
         SplitPaneArgs() = default;
+        SplitPaneArgs(SplitType splitMode, SplitState style, double size, const Model::NewTerminalArgs& terminalArgs) :
+            _SplitMode{ splitMode },
+            _SplitStyle{ style },
+            _SplitSize{ size },
+            _TerminalArgs{ terminalArgs } {};
         SplitPaneArgs(SplitState style, double size, const Model::NewTerminalArgs& terminalArgs) :
             _SplitStyle{ style },
             _SplitSize{ size },

src/cascadia/TerminalSettingsModel/ActionArgs.idl

@@ -152,6 +152,7 @@ namespace Microsoft.Terminal.Settings.Model
 
     [default_interface] runtimeclass SplitPaneArgs : IActionArgs
     {
+        SplitPaneArgs(SplitType splitMode, SplitState split, Double size, NewTerminalArgs terminalArgs);
         SplitPaneArgs(SplitState split, Double size, NewTerminalArgs terminalArgs);
         SplitPaneArgs(SplitState split, NewTerminalArgs terminalArgs);
         SplitPaneArgs(SplitType splitMode);