Allow @ as separator in #:package (#48542)

Author: jjonescz

documentation/general/dotnet-run-file.md

@@ -186,7 +186,7 @@ Other directives result in a warning, reserving them for future use.
 #:sdk Microsoft.NET.Sdk.Web
 #:property TargetFramework net11.0
 #:property LangVersion preview
-#:package System.CommandLine 2.0.0-*
+#:package System.CommandLine@2.0.0-*
 ```
 
 The value must be separated from the name of the directive by white space and any leading and trailing white space is not considered part of the value.

src/Cli/dotnet/Commands/Run/VirtualProjectBuildingCommand.cs

@@ -3,6 +3,7 @@
 
 #nullable enable
 
+using System.Buffers;
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Security;
@@ -814,9 +815,11 @@ public static CSharpDirective Parse(SourceFile sourceFile, TextSpan span, string
         };
     }
 
-    private static (string, string?) ParseOptionalTwoParts(SourceFile sourceFile, TextSpan span, string directiveKind, string directiveText)
+    private static (string, string?) ParseOptionalTwoParts(SourceFile sourceFile, TextSpan span, string directiveKind, string directiveText, SearchValues<char>? separators = null)
     {
-        var i = directiveText.IndexOf(' ', StringComparison.Ordinal);
+        var i = separators != null
+            ? directiveText.AsSpan().IndexOfAny(separators)
+            : directiveText.IndexOf(' ', StringComparison.Ordinal);
         var firstPart = checkFirstPart(i < 0 ? directiveText : directiveText[..i]);
         var secondPart = i < 0 ? [] : directiveText.AsSpan((i + 1)..).TrimStart();
         if (i < 0 || secondPart.IsWhiteSpace())
@@ -912,14 +915,16 @@ private Property() { }
     /// </summary>
     public sealed class Package : CSharpDirective
     {
+        private static readonly SearchValues<char> s_separators = SearchValues.Create(' ', '@');
+
         private Package() { }
 
         public required string Name { get; init; }
         public string? Version { get; init; }
 
         public static new Package Parse(SourceFile sourceFile, TextSpan span, string directiveKind, string directiveText)
         {
-            var (packageName, packageVersion) = ParseOptionalTwoParts(sourceFile, span, directiveKind, directiveText);
+            var (packageName, packageVersion) = ParseOptionalTwoParts(sourceFile, span, directiveKind, directiveText, s_separators);
 
             return new Package
             {

test/dotnet.Tests/CommandTests/Project/Convert/DotnetProjectConvertTests.cs

@@ -407,6 +407,7 @@ public void Directives_Separators()
                 #:sdk Third 3.0=a/b
                 #:package P1 1.0/a=b
                 #:package P2 2.0/a=b
+                #:package P3@1.0 ab
                 """,
             expectedProject: $"""
                 <Project Sdk="First/1.0=a/b">
@@ -429,6 +430,7 @@ public void Directives_Separators()
                   <ItemGroup>
                     <PackageReference Include="P1" Version="1.0/a=b" />
                     <PackageReference Include="P2" Version="2.0/a=b" />
+                    <PackageReference Include="P3" Version="1.0 ab" />
                   </ItemGroup>
 
                 </Project>