[Sonic] Support multiple C# documents in code actions by davidwengier · Pull Request #84203 · dotnet/roslyn

davidwengier · 2026-06-19T00:38:40Z

Review commit-at-a-time is recommended. Most of code actions was straight forward, except things like Generate Members, Implement Interface etc. which are dependent on which generated document the compiler sees first. Rather than assuming anything, I just made it request code actions for both documents if the mapping is valid for both. Also had to hard code the ProjectId we use in tests, otherwise the location of the generated code would move around, so expected output validation would fail.

While in here, I also found some Fully Qualify scenarios that were explicitly avoided, but they worked just fine. Probably have for a couple of years too :)

Microsoft Reviewers: Open in CodeFlow

This looked suspicious, so rather than fix it, I added some tests to prove that we don't need it any more, and removed it. Our code action handling is vastly improved since this was written, I'm guessing.

This is off topic, but I couldn't resist

This makes most of the tests pass, but I thought I'd tackle the edge cases in separate commits to make things easier

…nd abstract class still work as expected

Copilot

Pull request overview

This PR updates Razor cohosting code action plumbing to correctly handle scenarios where a Razor position can map to both generated C# documents (impl + optional decl), and adjusts tests accordingly so behavior is deterministic and exercised by default.

Changes:

Request delegated C# code actions for both generated documents when the Razor position is valid in both, then dedupe appropriately when returning results.
Update code action resolution/remapping/formatting paths to use the correct generated C# document (based on hint name / decl-vs-impl) and simplify some callers to operate on IDocumentSnapshot.
Enable previously skipped cohosting code action tests and add additional Fully Qualify coverage; stabilize test ProjectId to avoid nondeterministic generated document ordering.

Reviewed changes

Copilot reviewed 29 out of 29 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/ImplementInterfaceTests.cs	Unskips tests and updates expected output ordering for implement-interface scenarios.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/ImplementAbstractClassTests.cs	Unskips implement-abstract-class test coverage.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/GenerateTypeTests.cs	Unskips generate-type tests.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/GeneratePropertyTests.cs	Unskips generate-property tests.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/GenerateMethodTests.cs	Unskips generate-method tests and adjusts a formatting expectation.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/GenerateFieldTests.cs	Unskips generate-field tests.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/GenerateEventHandlerTests.cs	Unskips generate-event-handler tests.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/GenerateDeconstructMethodTests.cs	Unskips deconstruct-method tests.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/GenerateConversionTests.cs	Unskips conversion-generation tests.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/GenerateConstructorTests.cs	Unskips generate-constructor tests.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/CSharpCodeActionTests.cs	Unskips miscellaneous Roslyn C# code action tests.
src/Razor/src/Razor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/AddUsingTests.cs	Adds additional Fully Qualify scenarios and unskips related tests.
src/Razor/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Cohosting/CohostTestBase.cs	Stabilizes `ProjectId` so generated document IDs/order are deterministic for tests.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Formatting/RazorFormattingService.cs	Adjusts code-action formatting API to accept `IDocumentSnapshot` directly.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/CodeActions/RoslynCodeActionHelpers.cs	Ensures a specific generated C# document is selected when needed.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/CodeActions/RemoteCodeActionsService.cs	Produces both impl and decl delegated C# requests when applicable and passes both through.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/CodeActions/Razor/GenerateEventHandlerCodeActionResolver.cs	Routes code-action-style formatting/remapping through the updated formatting API.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/CodeActions/Razor/ComponentAccessibilityCodeActionProvider.cs	Switches diagnostic source to a document-selection API compatible with decl/impl split.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/CodeActions/ICodeActionsService.cs	Expands the service contract to accept html/csharp/decl-csharp code action arrays.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/CodeActions/CSharp/TypeAccessibilityCodeActionProvider.cs	Updates filtering/wrapping behavior and optimizes diagnostic allowlist lookup.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/CodeActions/CSharp/CSharpCodeActionResolver.cs	Remaps edits using the correct generated C# document chosen by hint name and formats appropriately.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/CodeActions/CodeActionsService.cs	Filters/de-dupes delegated actions from both generated C# documents and integrates new call shape.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Remote/IRemoteCodeActionsService.cs	Updates the remote service contract for the split delegated action arrays.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Remote/CodeActionRequestInfo.cs	Extends request info payload with an optional decl-document delegated request.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Protocol/LanguageServerConstants.cs	Removes the no-longer-used `UnformattedRemap` action constant.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Formatting/IRazorFormattingService.cs	Updates formatting service interface to match snapshot-based code-action formatting.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/DocumentMapping/IDocumentMappingServiceExtensions.cs	Small adjustment in `GetPositionInfo` flow for decl/impl mapping output.
src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Razor.CohostingShared/CodeActions/CohostCodeActionsEndpoint.cs	Fetches delegated code actions for both generated C# documents when provided by request info.

…s platforms and environments

Copilot

Pull request overview

Copilot reviewed 31 out of 31 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/CodeActions/CSharp/TypeAccessibilityCodeActionProvider.cs:37

Microsoft.CodeAnalysis.Remote.Razor targets netstandard2.0 (see src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Microsoft.CodeAnalysis.Remote.Razor.csproj), so FrozenSet<T> isn't available here. This will fail to compile for the netstandard2.0 TFMs. Consider using a HashSet<string> with an ordinal ignore-case comparer (or ImmutableHashSet<string>) instead.

    private static readonly FrozenSet<string> s_supportedDiagnostics = FrozenSet.Create(StringComparer.OrdinalIgnoreCase, [
        // `The type or namespace name 'type/namespace' could not be found
        //  (are you missing a using directive or an assembly reference?)`
        // https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/compiler-messages/cs0246
        "CS0246",

ToddGrun · 2026-06-20T00:11:46Z

-                    continue;
-                }
-                else if (IsExplicitExpressionNode(owner))
+                if (TryGetOwner(context, out var owner) &&


if (TryGetOwner(context, out var owner) &&

Probably doesn't matter, but there is a logical change here in that the old code would continue the loop if TryGetOwner return false.

Yep, this was deliberate on my part. My thinking was that previously we needed the the owner to filter out a number of scenarios because what we supported was quite narrow. Now we only care about one thing, and unless we're in that state, we let the normal system handle things, so if we can't get an owner, then we can't be in the one state we care about not offering for, so let it through.

In reality I suspect owner will never be null.

ToddGrun · 2026-06-20T00:27:07Z

+            ConvertCodeActionsToSumType(filteredCodeActions, "B-Delegated", csharpDocumentUri, seenTitles);
+        }
+
+        void ConvertCodeActionsToSumType(ImmutableArray<RazorVSInternalCodeAction> codeActions, string groupName, Uri? csharpDocumentUri = null, HashSet<string>? seenTitles = null)


? seenTitles = null

Why nullable?

We only de-dupe C# code actions, so for Razor and Html it's null (and not passed in, for brevity)

ToddGrun

davidwengier added 7 commits June 18, 2026 13:26

Unskip all code actions tests

af412e1

Remove "UnformattedRemapping" code action resovler and expand tests

1abce2d

This looked suspicious, so rather than fix it, I added some tests to prove that we don't need it any more, and removed it. Our code action handling is vastly improved since this was written, I'm guessing.

Use a frozen set

b2e620d

This is off topic, but I couldn't resist

Make code actions multi-document aware

1ccc101

This makes most of the tests pass, but I thought I'd tackle the edge cases in separate commits to make things easier

Request code actions from both C# documents, so implement interface a…

5a4d5fb

…nd abstract class still work as expected

Fix test output

8acbfb4

Make test runs deterministic

610b163

davidwengier requested a review from a team as a code owner June 19, 2026 00:38

Copilot AI review requested due to automatic review settings June 19, 2026 00:38

Copilot started reviewing on behalf of davidwengier June 19, 2026 00:39 View session

dotnet-policy-service Bot added the Area-Razor label Jun 19, 2026

Copilot AI reviewed Jun 19, 2026

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Comment thread ...zor/test/Microsoft.CodeAnalysis.Razor.CohostingShared.UnitTests/CodeActions/AddUsingTests.cs

Comment thread ...Razor/src/Microsoft.CodeAnalysis.Remote.Razor/CodeActions/CSharp/CSharpCodeActionResolver.cs

davidwengier added 2 commits June 19, 2026 10:45

PR Feedback

f5b8799

Keep the SG path stable to get predictable DocumentIds in tests acros…

898a90d

…s platforms and environments

Copilot AI review requested due to automatic review settings June 19, 2026 04:53

Copilot started reviewing on behalf of davidwengier June 19, 2026 04:54 View session

Copilot AI reviewed Jun 19, 2026

View reviewed changes

Comment thread ...icrosoft.CodeAnalysis.Remote.Razor/CodeActions/CSharp/TypeAccessibilityCodeActionProvider.cs

Comment thread ....Common.Tooling/Workspaces/RazorProjectBuilder.DeterministicRazorSourceGeneratorReference.cs

ToddGrun reviewed Jun 20, 2026

View reviewed changes

ToddGrun approved these changes Jun 20, 2026

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davidwengier merged commit 1e531bd into dotnet:features/sonic Jun 20, 2026
25 checks passed

davidwengier deleted the SonicCodeActions branch June 20, 2026 01:50

dotnet-maestro Bot mentioned this pull request Aug 7, 2026

[main] Source code updates from dotnet/roslyn dotnet/dotnet#8179

Merged

dibarbet mentioned this pull request Aug 8, 2026

Update roslyn to 5.11.0-1.26407.4 dibarbet/vscode-csharp#19

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davidwengier mentioned this pull request Aug 9, 2026

Update roslyn to 5.11.0-1.26405.8 dotnet/vscode-csharp#9656

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dotnet-bot mentioned this pull request Aug 13, 2026

[Automated] PRs inserted in VS build main-12112.60 #84875

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davidwengier mentioned this pull request Aug 24, 2026

Update roslyn to 5.11.0-1.26424.9 dotnet/vscode-csharp#9701

Merged

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[Sonic] Support multiple C# documents in code actions - #84203

[Sonic] Support multiple C# documents in code actions#84203
davidwengier merged 9 commits into
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