From d6c0447859d16dc28da39a6ea254437cd57eee6a Mon Sep 17 00:00:00 2001
From: Rolf Bjarne Kvinge <rolf@xamarin.com>
Date: Wed, 18 Aug 2021 12:11:04 +0200
Subject: [PATCH] [dotnet] Update logic for default global namespaces and fix
 the templates. Fixes #12457.

* Add 'ImplicitUsings=true' to all the templates.
* Make the implicit global namespaces C#-only.
* Add the implicit global namespaces to the 'Using' itemgroup instead of the
  'Import' itemgroup.
* Make sure the global namespaces are set from AutoImport.props, so that the
  user may remove any global namespace they don't want in their project file
  (by doing something like: `<Using Remove="Foundation" />`)

Ref: https://github.com/dotnet/sdk/issues/19521
Ref: https://github.com/dotnet/sdk/issues/19793

Fixes https://github.com/xamarin/xamarin-macios/issues/12457.
---
 .../Microsoft.MacCatalyst.Sdk/Sdk/AutoImport.props  |  1 +
 dotnet/Microsoft.iOS.Sdk/Sdk/AutoImport.props       |  1 +
 dotnet/Microsoft.macOS.Sdk/Sdk/AutoImport.props     |  1 +
 dotnet/Microsoft.tvOS.Sdk/Sdk/AutoImport.props      |  1 +
 dotnet/Microsoft.watchOS.Sdk/Sdk/AutoImport.props   |  1 +
 .../maccatalyst/MacCatalystApp1.csproj              |  1 +
 .../Microsoft.iOS.Templates/ios/iOSApp1.csproj      |  1 +
 .../Microsoft.iOS.Templates/ioslib/iOSLib1.csproj   |  1 +
 .../macos/macOSApp1.csproj                          |  1 +
 .../Microsoft.tvOS.Templates/tvos/tvOSApp1.csproj   |  1 +
 ...t.MacCatalyst.Sdk.ImplicitNamespaceImports.props | 13 ++++++++-----
 ...Microsoft.iOS.Sdk.ImplicitNamespaceImports.props | 13 ++++++++-----
 ...crosoft.macOS.Sdk.ImplicitNamespaceImports.props | 13 ++++++++-----
 ...icrosoft.tvOS.Sdk.ImplicitNamespaceImports.props | 13 ++++++++-----
 dotnet/targets/Xamarin.Shared.Sdk.props             |  3 ---
 tests/dotnet/UnitTests/TemplateTest.cs              |  1 -
 16 files changed, 42 insertions(+), 24 deletions(-)

diff --git a/dotnet/Microsoft.MacCatalyst.Sdk/Sdk/AutoImport.props b/dotnet/Microsoft.MacCatalyst.Sdk/Sdk/AutoImport.props
index bec641d41ad8..0ba5cc02ef81 100644
--- a/dotnet/Microsoft.MacCatalyst.Sdk/Sdk/AutoImport.props
+++ b/dotnet/Microsoft.MacCatalyst.Sdk/Sdk/AutoImport.props
@@ -1,3 +1,4 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 	<Import Project="..\targets\Microsoft.MacCatalyst.Sdk.DefaultItems.props" />
+	<Import Project="..\targets\Microsoft.MacCatalyst.Sdk.ImplicitNamespaceImports.props" />
 </Project>
diff --git a/dotnet/Microsoft.iOS.Sdk/Sdk/AutoImport.props b/dotnet/Microsoft.iOS.Sdk/Sdk/AutoImport.props
index 01d5383cb887..83ef903c8b4f 100644
--- a/dotnet/Microsoft.iOS.Sdk/Sdk/AutoImport.props
+++ b/dotnet/Microsoft.iOS.Sdk/Sdk/AutoImport.props
@@ -1,3 +1,4 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 	<Import Project="..\targets\Microsoft.iOS.Sdk.DefaultItems.props" />
+	<Import Project="..\targets\Microsoft.iOS.Sdk.ImplicitNamespaceImports.props" />
 </Project>
diff --git a/dotnet/Microsoft.macOS.Sdk/Sdk/AutoImport.props b/dotnet/Microsoft.macOS.Sdk/Sdk/AutoImport.props
index 918e7b9ad484..4a14b1ed8dab 100644
--- a/dotnet/Microsoft.macOS.Sdk/Sdk/AutoImport.props
+++ b/dotnet/Microsoft.macOS.Sdk/Sdk/AutoImport.props
@@ -1,3 +1,4 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 	<Import Project="..\targets\Microsoft.macOS.Sdk.DefaultItems.props" />
+	<Import Project="..\targets\Microsoft.macOS.Sdk.ImplicitNamespaceImports.props" />
 </Project>
diff --git a/dotnet/Microsoft.tvOS.Sdk/Sdk/AutoImport.props b/dotnet/Microsoft.tvOS.Sdk/Sdk/AutoImport.props
index 89b739355968..37faf34376e2 100644
--- a/dotnet/Microsoft.tvOS.Sdk/Sdk/AutoImport.props
+++ b/dotnet/Microsoft.tvOS.Sdk/Sdk/AutoImport.props
@@ -1,3 +1,4 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 	<Import Project="..\targets\Microsoft.tvOS.Sdk.DefaultItems.props" />
+	<Import Project="..\targets\Microsoft.tvOS.Sdk.ImplicitNamespaceImports.props" />
 </Project>
diff --git a/dotnet/Microsoft.watchOS.Sdk/Sdk/AutoImport.props b/dotnet/Microsoft.watchOS.Sdk/Sdk/AutoImport.props
index ca0479bdaaba..e909c261726c 100644
--- a/dotnet/Microsoft.watchOS.Sdk/Sdk/AutoImport.props
+++ b/dotnet/Microsoft.watchOS.Sdk/Sdk/AutoImport.props
@@ -1,3 +1,4 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 	<Import Project="..\targets\Microsoft.watchOS.Sdk.DefaultItems.props" />
+	<Import Project="..\targets\Microsoft.watchOS.Sdk.ImplicitNamespaceImports.props" />
 </Project>
diff --git a/dotnet/Templates/Microsoft.MacCatalyst.Templates/maccatalyst/MacCatalystApp1.csproj b/dotnet/Templates/Microsoft.MacCatalyst.Templates/maccatalyst/MacCatalystApp1.csproj
index 8b6d851d3743..88fd065da8b1 100644
--- a/dotnet/Templates/Microsoft.MacCatalyst.Templates/maccatalyst/MacCatalystApp1.csproj
+++ b/dotnet/Templates/Microsoft.MacCatalyst.Templates/maccatalyst/MacCatalystApp1.csproj
@@ -5,5 +5,6 @@
     <RootNamespace Condition="'$(name)' != '$(name{-VALUE-FORMS-}safe_namespace)'">MacCatalystApp1</RootNamespace>
     <OutputType>Exe</OutputType>
     <Nullable>enable</Nullable>
+    <ImplicitUsings>true</ImplicitUsings>
   </PropertyGroup>
 </Project>
diff --git a/dotnet/Templates/Microsoft.iOS.Templates/ios/iOSApp1.csproj b/dotnet/Templates/Microsoft.iOS.Templates/ios/iOSApp1.csproj
index 509800f424d2..887acc2eb3a7 100644
--- a/dotnet/Templates/Microsoft.iOS.Templates/ios/iOSApp1.csproj
+++ b/dotnet/Templates/Microsoft.iOS.Templates/ios/iOSApp1.csproj
@@ -4,5 +4,6 @@
     <RootNamespace Condition="'$(name)' != '$(name{-VALUE-FORMS-}safe_namespace)'">iOSApp1</RootNamespace>
     <OutputType>Exe</OutputType>
     <Nullable>enable</Nullable>
+    <ImplicitUsings>true</ImplicitUsings>
   </PropertyGroup>
 </Project>
diff --git a/dotnet/Templates/Microsoft.iOS.Templates/ioslib/iOSLib1.csproj b/dotnet/Templates/Microsoft.iOS.Templates/ioslib/iOSLib1.csproj
index 64e83d5cbef7..984bbf660e67 100644
--- a/dotnet/Templates/Microsoft.iOS.Templates/ioslib/iOSLib1.csproj
+++ b/dotnet/Templates/Microsoft.iOS.Templates/ioslib/iOSLib1.csproj
@@ -3,5 +3,6 @@
     <TargetFramework>net6.0-ios</TargetFramework>
     <RootNamespace Condition="'$(name)' != '$(name{-VALUE-FORMS-}safe_namespace)'">iOSLib1</RootNamespace>
     <Nullable>enable</Nullable>
+    <ImplicitUsings>true</ImplicitUsings>
   </PropertyGroup>
 </Project>
diff --git a/dotnet/Templates/Microsoft.macOS.Templates/macos/macOSApp1.csproj b/dotnet/Templates/Microsoft.macOS.Templates/macos/macOSApp1.csproj
index 885d47ba82f2..2d0a6b324cfd 100644
--- a/dotnet/Templates/Microsoft.macOS.Templates/macos/macOSApp1.csproj
+++ b/dotnet/Templates/Microsoft.macOS.Templates/macos/macOSApp1.csproj
@@ -4,5 +4,6 @@
     <RootNamespace Condition="'$(name)' != '$(name{-VALUE-FORMS-}safe_namespace)'">macOSApp1</RootNamespace>
     <OutputType>Exe</OutputType>
     <Nullable>enable</Nullable>
+    <ImplicitUsings>true</ImplicitUsings>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/dotnet/Templates/Microsoft.tvOS.Templates/tvos/tvOSApp1.csproj b/dotnet/Templates/Microsoft.tvOS.Templates/tvos/tvOSApp1.csproj
index dff9551ee5b3..cf0351ad5c28 100644
--- a/dotnet/Templates/Microsoft.tvOS.Templates/tvos/tvOSApp1.csproj
+++ b/dotnet/Templates/Microsoft.tvOS.Templates/tvos/tvOSApp1.csproj
@@ -4,5 +4,6 @@
     <RootNamespace Condition="'$(name)' != '$(name{-VALUE-FORMS-}safe_namespace)'">tvOSApp1</RootNamespace>
     <OutputType>Exe</OutputType>
     <Nullable>enable</Nullable>
+    <ImplicitUsings>true</ImplicitUsings>
   </PropertyGroup>
 </Project>
diff --git a/dotnet/targets/Microsoft.MacCatalyst.Sdk.ImplicitNamespaceImports.props b/dotnet/targets/Microsoft.MacCatalyst.Sdk.ImplicitNamespaceImports.props
index 11080e7ef127..501bb805518b 100644
--- a/dotnet/targets/Microsoft.MacCatalyst.Sdk.ImplicitNamespaceImports.props
+++ b/dotnet/targets/Microsoft.MacCatalyst.Sdk.ImplicitNamespaceImports.props
@@ -18,10 +18,13 @@
 -->
 
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-	<!-- There's a master switch, DisableImplicitNamespaceImports, which, if set, will prevent all implicit namespace imports - this is done automatically, we don't have to check DisableImplicitNamespaceImports here -->
-	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'MacCatalyst' And '$(DisableImplicitNamespaceImports_MacCatalyst)' != 'true'">
-		<Import Include="CoreGraphics" />
-		<Import Include="Foundation" />
-		<Import Include="UIKit" />
+	<!--
+		These implicit usings are C#-specific, and governed by a single global property: ImplicitUsings, which can be either 'true' or 'enable'.
+		Ref: https://github.com/dotnet/sdk/issues/19793#issuecomment-900620060
+	-->
+	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'MacCatalyst' And '$(Language)' == 'C#' And ('$(ImplicitUsings)' == 'true' or '$(ImplicitUsings)' == 'enable')">
+		<Using Include="CoreGraphics" />
+		<Using Include="Foundation" />
+		<Using Include="UIKit" />
 	</ItemGroup>
 </Project>
diff --git a/dotnet/targets/Microsoft.iOS.Sdk.ImplicitNamespaceImports.props b/dotnet/targets/Microsoft.iOS.Sdk.ImplicitNamespaceImports.props
index b1f93fd573ea..849d76fcfa6f 100644
--- a/dotnet/targets/Microsoft.iOS.Sdk.ImplicitNamespaceImports.props
+++ b/dotnet/targets/Microsoft.iOS.Sdk.ImplicitNamespaceImports.props
@@ -18,10 +18,13 @@
 -->
 
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-	<!-- There's a master switch, DisableImplicitNamespaceImports, which, if set, will prevent all implicit namespace imports - this is done automatically, we don't have to check DisableImplicitNamespaceImports here -->
-	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'iOS' And '$(DisableImplicitNamespaceImports_iOS)' != 'true'">
-		<Import Include="CoreGraphics" />
-		<Import Include="Foundation" />
-		<Import Include="UIKit" />
+	<!--
+		These implicit usings are C#-specific, and governed by a single global property: ImplicitUsings, which can be either 'true' or 'enable'.
+		Ref: https://github.com/dotnet/sdk/issues/19793#issuecomment-900620060
+	-->
+	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'iOS' And '$(Language)' == 'C#' And ('$(ImplicitUsings)' == 'true' or '$(ImplicitUsings)' == 'enable')">
+		<Using Include="CoreGraphics" />
+		<Using Include="Foundation" />
+		<Using Include="UIKit" />
 	</ItemGroup>
 </Project>
diff --git a/dotnet/targets/Microsoft.macOS.Sdk.ImplicitNamespaceImports.props b/dotnet/targets/Microsoft.macOS.Sdk.ImplicitNamespaceImports.props
index 11c0483e7986..5874f46852a0 100644
--- a/dotnet/targets/Microsoft.macOS.Sdk.ImplicitNamespaceImports.props
+++ b/dotnet/targets/Microsoft.macOS.Sdk.ImplicitNamespaceImports.props
@@ -18,10 +18,13 @@
 -->
 
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-	<!-- There's a master switch, DisableImplicitNamespaceImports, which, if set, will prevent all implicit namespace imports - this is done automatically, we don't have to check DisableImplicitNamespaceImports here -->
-	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'macOS' And '$(DisableImplicitNamespaceImports_macOS)' != 'true'">
-		<Import Include="AppKit" />
-		<Import Include="CoreGraphics" />
-		<Import Include="Foundation" />
+	<!--
+		These implicit usings are C#-specific, and governed by a single global property: ImplicitUsings, which can be either 'true' or 'enable'.
+		Ref: https://github.com/dotnet/sdk/issues/19793#issuecomment-900620060
+	-->
+	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'macOS' And '$(Language)' == 'C#' And ('$(ImplicitUsings)' == 'true' or '$(ImplicitUsings)' == 'enable')">
+		<Using Include="AppKit" />
+		<Using Include="CoreGraphics" />
+		<Using Include="Foundation" />
 	</ItemGroup>
 </Project>
diff --git a/dotnet/targets/Microsoft.tvOS.Sdk.ImplicitNamespaceImports.props b/dotnet/targets/Microsoft.tvOS.Sdk.ImplicitNamespaceImports.props
index 50e58beb4d9e..afce3dae2e3f 100644
--- a/dotnet/targets/Microsoft.tvOS.Sdk.ImplicitNamespaceImports.props
+++ b/dotnet/targets/Microsoft.tvOS.Sdk.ImplicitNamespaceImports.props
@@ -18,10 +18,13 @@
 -->
 
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-	<!-- There's a master switch, DisableImplicitNamespaceImports, which, if set, will prevent all implicit namespace imports - this is done automatically, we don't have to check DisableImplicitNamespaceImports here -->
-	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'tvOS' And '$(DisableImplicitNamespaceImports_tvOS)' != 'true'">
-		<Import Include="CoreGraphics" />
-		<Import Include="Foundation" />
-		<Import Include="UIKit" />
+	<!--
+		These implicit usings are C#-specific, and governed by a single global property: ImplicitUsings, which can be either 'true' or 'enable'.
+		Ref: https://github.com/dotnet/sdk/issues/19793#issuecomment-900620060
+	-->
+	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'tvOS' And '$(Language)' == 'C#' And ('$(ImplicitUsings)' == 'true' or '$(ImplicitUsings)' == 'enable')">
+		<Using Include="CoreGraphics" />
+		<Using Include="Foundation" />
+		<Using Include="UIKit" />
 	</ItemGroup>
 </Project>
diff --git a/dotnet/targets/Xamarin.Shared.Sdk.props b/dotnet/targets/Xamarin.Shared.Sdk.props
index 9f55fc11ad23..7fcfbf48b5e5 100644
--- a/dotnet/targets/Xamarin.Shared.Sdk.props
+++ b/dotnet/targets/Xamarin.Shared.Sdk.props
@@ -6,9 +6,6 @@
 	<!-- This contains the OS versions we support for target platform -->
 	<Import Project="Microsoft.$(_PlatformName).Sdk.SupportedTargetPlatforms.props" />
 
-	<!-- This contains support for implicit namespace imports -->
-	<Import Project="Microsoft.$(_PlatformName).Sdk.ImplicitNamespaceImports.props" />
-
 	<Import Project="Xamarin.Shared.Sdk.TargetFrameworkInference.props" />
 
 	<PropertyGroup>
diff --git a/tests/dotnet/UnitTests/TemplateTest.cs b/tests/dotnet/UnitTests/TemplateTest.cs
index d9121a770574..73d8d9c36e99 100644
--- a/tests/dotnet/UnitTests/TemplateTest.cs
+++ b/tests/dotnet/UnitTests/TemplateTest.cs
@@ -66,7 +66,6 @@ public void AreAllTemplatesListed ()
 
 		[Test]
 		[TestCaseSource (nameof (Templates))]
-		[Ignore ("https://github.com/xamarin/xamarin-macios/issues/12457")]
 		public void CreateAndBuildTemplate (string platform, string template)
 		{
 			Configuration.IgnoreIfIgnoredPlatform (platform);