Make Avalonia UI the default on all platforms and move in-process (#1207)

Today GCM has an architecture that delegates all GUI prompting to
(bundled) external executables, using WPF-based helpers on Windows and
Avalonia UI helpers on Mac and Linux. Each host provider has its own GUI
helper executable, meaning we currently bundle four (GitHub.UI,
GitLab.UI, Atlassian.Bitbucket.UI, git-credential-manager.ui [for
generic auth]) helpers in addition to the core git-credential-manager
CLI executable.

On Linux we use the "publish as a single-file" model for each of these
executables, meaning we have a copy of the CLR included for each
executable! That means five CLRs!

Now that the Avalonia UI-based GUI helpers have matured, we can look at
dropping the WPF helpers and reduce the effort required to ship new GUI
by 50% (we no longer need to do everything twice: once with WPF and once
with Avalonia UI).

In addition, in a recent spike, I found that it may be possible to bring
the Avalonia UI helpers in-process, with nearly zero net-new code. This
would help reduce our installation footprint on Linux down to
approximately 1/4 of the current size. The single executable model would
also help decrease build times, and increase end-user performance since
we no longer pay the process startup costs using external processes!

We need to be mindful that this change may result in a small increase in
the Windows installation as we now bring in extra libraries used to
support Avalonia UI, whereas previously we relied on WPF libraries as
included with Windows 'for free'. This is expected to be minimal.

As for the current GUI extensibility model, we are not aware of any
consumers, but it would not be much effort to keep the existing external
process model, but now just default to using our in-process GUI options
in the absence of external configuration. This still gives tools like VS
or VSCode options to integrate native UI for GCM in the future.

Initially, we are still keeping the WPF helpers around on Windows but
disabled by default.
We can drop these after at least one release using the in-proc Avalonia
helpers.

To switch back to the WPF helpers, use
`credential.devUseLegacyUIHelpers` or `GCM_DEV_USELEGACYUIHELPERS`.

Author: mjcheetham

Git-Credential-Manager.sln

@@ -17,10 +17,6 @@
 
   <ItemGroup>
     <ProjectReference Include="../../shared/Git-Credential-Manager/Git-Credential-Manager.csproj" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="../../shared/Atlassian.Bitbucket.UI.Avalonia/Atlassian.Bitbucket.UI.Avalonia.csproj" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="../../shared/GitHub.UI.Avalonia/GitHub.UI.Avalonia.csproj" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="../../shared/GitLab.UI.Avalonia/GitLab.UI.Avalonia.csproj" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="../../shared/Core.UI.Avalonia/Core.UI.Avalonia.csproj" ReferenceOutputAssembly="false" />
   </ItemGroup>
 
   <!-- Implicit SDK targets import (so we can override the default targets below) -->

src/linux/Packaging.Linux/Packaging.Linux.csproj

@@ -35,10 +35,6 @@ ROOT="$( cd "$THISDIR"/../../.. ; pwd -P )"
 SRC="$ROOT/src"
 OUT="$ROOT/out"
 GCM_SRC="$SRC/shared/Git-Credential-Manager"
-GCM_UI_SRC="$SRC/shared/Git-Credential-Manager.UI.Avalonia"
-BITBUCKET_UI_SRC="$SRC/shared/Atlassian.Bitbucket.UI.Avalonia"
-GITHUB_UI_SRC="$SRC/shared/GitHub.UI.Avalonia"
-GITLAB_UI_SRC="$SRC/shared/GitLab.UI.Avalonia"
 PROJ_OUT="$OUT/linux/Packaging.Linux"
 
 # Build parameters
@@ -81,42 +77,6 @@ $DOTNET_ROOT/dotnet publish "$GCM_SRC" \
 	-p:PublishSingleFile=true \
 	--output="$(make_absolute "$PAYLOAD")" || exit 1
 
-echo "Publishing core UI helper..."
-$DOTNET_ROOT/dotnet publish "$GCM_UI_SRC" \
-	--configuration="$CONFIGURATION" \
-	--framework="$FRAMEWORK" \
-	--runtime="$RUNTIME" \
-	--self-contained \
-	-p:PublishSingleFile=true \
-	--output="$(make_absolute "$PAYLOAD")" || exit 1
-
-echo "Publishing Bitbucket UI helper..."
-$DOTNET_ROOT/dotnet publish "$BITBUCKET_UI_SRC" \
-	--configuration="$CONFIGURATION" \
-	--framework="$FRAMEWORK" \
-	--runtime="$RUNTIME" \
-	--self-contained \
-	-p:PublishSingleFile=true \
-	--output="$(make_absolute "$PAYLOAD")" || exit 1
-
-echo "Publishing GitHub UI helper..."
-$DOTNET_ROOT/dotnet publish "$GITHUB_UI_SRC" \
-	--configuration="$CONFIGURATION" \
-	--framework="$FRAMEWORK" \
-	--runtime="$RUNTIME" \
-	--self-contained \
-	-p:PublishSingleFile=true \
-	--output="$(make_absolute "$PAYLOAD")" || exit 1
-
-echo "Publishing GitLab UI helper..."
-$DOTNET_ROOT/dotnet publish "$GITLAB_UI_SRC" \
-	--configuration="$CONFIGURATION" \
-	--framework="$FRAMEWORK" \
-	--runtime="$RUNTIME" \
-	--self-contained=true \
-	-p:PublishSingleFile=true \
-	--output="$(make_absolute "$PAYLOAD")" || exit 1
-
 # Collect symbols
 echo "Collecting managed symbols..."
 mv "$PAYLOAD"/*.pdb "$SYMBOLOUT" || exit 1

src/linux/Packaging.Linux/layout.sh

@@ -13,10 +13,6 @@
 
   <ItemGroup>
     <ProjectReference Include="../../shared/Git-Credential-Manager/Git-Credential-Manager.csproj" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="../../shared/Atlassian.Bitbucket.UI.Avalonia/Atlassian.Bitbucket.UI.Avalonia.csproj" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="../../shared/GitHub.UI.Avalonia/GitHub.UI.Avalonia.csproj" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="../../shared/GitLab.UI.Avalonia/GitLab.UI.Avalonia.csproj" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="../../shared/Core.UI.Avalonia/Core.UI.Avalonia.csproj" ReferenceOutputAssembly="false" />
   </ItemGroup>
 
   <!-- Implicit SDK targets import (so we can override the default targets below) -->

src/osx/Installer.Mac/Installer.Mac.csproj

@@ -22,9 +22,6 @@ OUT="$ROOT/out"
 INSTALLER_SRC="$SRC/osx/Installer.Mac"
 GCM_SRC="$SRC/shared/Git-Credential-Manager"
 GCM_UI_SRC="$SRC/shared/Git-Credential-Manager.UI.Avalonia"
-BITBUCKET_UI_SRC="$SRC/shared/Atlassian.Bitbucket.UI.Avalonia"
-GITHUB_UI_SRC="$SRC/shared/GitHub.UI.Avalonia"
-GITLAB_UI_SRC="$SRC/shared/GitLab.UI.Avalonia"
 
 # Build parameters
 FRAMEWORK=net6.0
@@ -103,38 +100,6 @@ dotnet publish "$GCM_SRC" \
 	--self-contained \
 	--output="$(make_absolute "$PAYLOAD")" || exit 1
 
-echo "Publishing core UI helper..."
-dotnet publish "$GCM_UI_SRC" \
-	--configuration="$CONFIGURATION" \
-	--framework="$FRAMEWORK" \
-	--runtime="$RUNTIME" \
-	--self-contained \
-	--output="$(make_absolute "$PAYLOAD")" || exit 1
-
-echo "Publishing Bitbucket UI helper..."
-dotnet publish "$BITBUCKET_UI_SRC" \
-	--configuration="$CONFIGURATION" \
-	--framework="$FRAMEWORK" \
-	--runtime="$RUNTIME" \
-	--self-contained \
-	--output="$(make_absolute "$PAYLOAD")" || exit 1
-
-echo "Publishing GitHub UI helper..."
-dotnet publish "$GITHUB_UI_SRC" \
-	--configuration="$CONFIGURATION" \
-	--framework="$FRAMEWORK" \
-	--runtime="$RUNTIME" \
-	--self-contained \
-	--output="$(make_absolute "$PAYLOAD")" || exit 1
-
-echo "Publishing GitLab UI helper..."
-dotnet publish "$GITLAB_UI_SRC" \
-	--configuration="$CONFIGURATION" \
-	--framework="$FRAMEWORK" \
-	--runtime="$RUNTIME" \
-	--self-contained \
-	--output="$(make_absolute "$PAYLOAD")" || exit 1
-
 # Collect symbols
 echo "Collecting managed symbols..."
 mv "$PAYLOAD"/*.pdb "$SYMBOLOUT" || exit 1

src/osx/Installer.Mac/layout.sh

@@ -51,6 +51,7 @@ public async Task BitbucketAuthentication_GetCredentialsAsync_All_ShowsMenu_OAut
         {
             var context = new TestCommandContext();
             context.SessionManager.IsDesktopSession = true; // Allow OAuth mode
+            context.Settings.IsGuiPromptsEnabled = false; // Force text prompts
             context.Terminal.Prompts["option (enter for default)"] = "1";
             Uri targetUri = null;
 
@@ -71,6 +72,7 @@ public async Task BitbucketAuthentication_GetCredentialsAsync_All_ShowsMenu_Basi
 
             var context = new TestCommandContext();
             context.SessionManager.IsDesktopSession = true; // Allow OAuth mode
+            context.Settings.IsGuiPromptsEnabled = false; // Force text prompts
             context.Terminal.Prompts["option (enter for default)"] = "2";
             context.Terminal.Prompts["Username"] = username;
             context.Terminal.SecretPrompts["Password"] = password;