Test plan for "file-scoped namespace declarations"

[jcouv]

Championed feature: dotnet/csharplang#137
Speclet at: https://github.com/dotnet/csharplang/blob/main/proposals/csharp-10.0/file-scoped-namespaces.md

(checklist currently references changes in #54669)

Compiler

• LangVer (see NamespaceWithSemicolon_CSharp9)
• Multiple file-scoped declarations (see MultipleSingleLineNamespaces)
• Mix and match declarations (see MultipleFileScopedNamespaces)
• GetDeclaredSymbol in mix&match scenarios (see TestGetDeclaredSymbolFromNestedNamespace)
• File-scoped declaration after type (see NamespaceWithPrecedingType)
• test with top-level statement (see FileScopedNamespaceWithPrecedingStatement)
• lookup rules, LookupSymbols (binder chain) (see SemanticModelAPITests.LookupInNamespace)
• double-check all NamespaceDeclarationSyntax and SyntaxKind.NamespaceDeclaration references have been adjusted after merge from main branch
  • note: this was done in the compiler but many places outside the compiler might still need to be changed. See Test plan for "file-scoped namespace declarations" #49000 (comment)
• PROTOTYPE markers
• EnC (manual validation)
• smoke build of VS
• can debug and set breakpoints (manual validation)
• public API review
• SyntaxNormalizer (see SyntaxNormalizerTests.TestFileScopedNamespace)

Productivity

• Formatting
  • Currently, changing a "regular" namespace declaration to file-scoped doesn't automatically unindent the subsequent members. I do not know if this should change or not.
• Indentation
• Classification
• Completion
• FAR (manual validation)
• NavBar (manual validation)
• Convert to file-scoped namespace + code style preference
• Remove unused usings
  • Currently doesn't work following a file-scoped namespace
• Move type to new file
  • Currently this doesn't work at all in the presence of a file-scoped namespace (even for members that precede the namespace)
• Region collapsing (seems fine as-is)
  • Currently, we can't collapse the file scoped namespace's members into the namespace
• LocationInfo currently doesn't work properly. See the following test:

  roslyn/src/EditorFeatures/CSharpTest/Debugging/LocationInfoGetterTests.cs

  Lines 71 to 87 in 9bcecd9

  	[Fact, Trait(Traits.Feature, Traits.Features.DebuggingLocationName)]
  	[WorkItem(49000, "https://github.com/dotnet/roslyn/issues/49000")]
  	public async Task TestFileScopedNamespace()
  	{
  	// This test behavior is incorrect. This should be Namespace.Class.Method.
  	// See the associated WorkItem for details.
  	await TestAsync(
  	@"namespace Namespace;
  	class Class
  	{
  	void Method()
  	{
  	}$$
  	}
  	", "Class.Method()", 2);
  	}

  • This doesn't seem to impact debugging, navbar, etc. It's not clear to me (@RikkiGibson) what pain is introduced if we merge before fixing this.