[msbuild] Fix nullability issue when compiling for legacy Xamarin. (#17716)

rolfbjarne · web-flow · commit a39cefa45750 · 2023-03-07T07:54:21.000+01:00
And make sure we don't ignore any such warnings again for a few test projects.
diff --git a/tests/common/DotNet.cs b/tests/common/DotNet.cs
@@ -91,7 +91,11 @@ public static ExecutionResult AssertNew (string outputDirectory, string template
 				args.Add (name!);
 			}
 
+#if NET
 			if (!string.IsNullOrEmpty (language)) {
+#else
+			if (language is not null && !string.IsNullOrEmpty (language)) {
+#endif
 				args.Add ("--language");
 				args.Add (language);
 			}
diff --git a/tests/msbuild/Xamarin.MacDev.Tasks.Tests/Xamarin.MacDev.Tasks.Tests.csproj b/tests/msbuild/Xamarin.MacDev.Tasks.Tests/Xamarin.MacDev.Tasks.Tests.csproj
@@ -8,6 +8,7 @@
     <DefineConstants>$(DefineConstants);MSBUILD_TASKS</DefineConstants>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>../../../product.snk</AssemblyOriginatorKeyFile>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
   </PropertyGroup>
 
   <!--
diff --git a/tests/msbuild/Xamarin.MacDev.Tests/Xamarin.MacDev.Tests.csproj b/tests/msbuild/Xamarin.MacDev.Tests/Xamarin.MacDev.Tests.csproj
@@ -7,6 +7,7 @@
     <LangVersion>latest</LangVersion>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>../../../product.snk</AssemblyOriginatorKeyFile>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="NUnit" Version="3.12.0" />

Original file line number	Diff line number	Diff line change
`@@ -91,7 +91,11 @@ public static ExecutionResult AssertNew (string outputDirectory, string template`
`91`	`91`	`args.Add (name!);`
`92`	`92`	`}`
`93`	`93`
	`94`	`+#if NET`
`94`	`95`	`if (!string.IsNullOrEmpty (language)) {`
	`96`	`+#else`
	`97`	`+ if (language is not null && !string.IsNullOrEmpty (language)) {`
	`98`	`+#endif`
`95`	`99`	`args.Add ("--language");`
`96`	`100`	`args.Add (language);`
`97`	`101`	`}`