if you have: readonly ref int x = ref y does this count as a read/write ref now? or just a read-ref? It should be the latter. Can you check, fix if necessary, and add test?

[sharwell]

if you have: readonly ref int x = ref y does this count as a read/write ref now? or just a read-ref? It should be the latter. Can you check, fix if necessary, and add test?

Originally posted by @CyrusNajmabadi in #58459 (comment)

Follow-up to #58459

[mavasani]

@CyrusNajmabadi @sharwell This case seems to be already addressed in the existing code and we also have a test validating the same:

roslyn/src/Analyzers/CSharp/Tests/MakeFieldReadonly/MakeFieldReadonlyTests.cs

Lines 1611 to 1634 in 678b269

	[Fact, Trait(Traits.Feature, Traits.Features.CodeActionsMakeFieldReadonly)]
	public async Task FieldAssignedToLocalReadOnlyRef()
	{
	await TestInRegularAndScript1Async(
	@"
	class Program
	{
	[|int i;|]
	void M()
	{
	ref readonly var value = ref i;
	}
	}",
	@"
	class Program
	{
	[|readonly int i;|]
	void M()
	{
	ref readonly var value = ref i;
	}
	}");

The product code handling this case is below:

roslyn/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/Extensions/OperationExtensions.cs

Lines 206 to 219 in 678b269

	else if (operation.Parent is IVariableInitializerOperation variableInitializerOperation)
	{
	if (variableInitializerOperation.Parent is IVariableDeclaratorOperation variableDeclaratorOperation)
	{
	switch (variableDeclaratorOperation.Symbol.RefKind)
	{
	case RefKind.Ref:
	return ValueUsageInfo.ReadableWritableReference;
	case RefKind.RefReadOnly:
	return ValueUsageInfo.ReadableReference;
	}
	}
	}

Note that readonly ref is only valid for a variable declaration, not a simple assignment, my recent PR #58459 handled the missing simple assignment with ref case.

[mavasani]

Synced with Cyrus, closing issue.