Ensure `LspWorkspaceManager` returns solutions without misc document when file moved #80535

dibarbet · 2025-10-01T18:32:07Z

Resolves https://devdiv.visualstudio.com/DevDiv/_workitems/edit/2576168

When the diagnostics handler was looking up documentIds to compare the previous results, it uses GetTextDocumentAsync on the LSP text doc identifier. However, in document pull, the diagnostics originally get computed against the requestContext.Document, as determined by the LspWorkspaceManager.

Generally this is not an issue, the lookup from document URI -> document is intended to be stable, regardless of if a project context is provided or not.

However this was broken with file based programs. Consider the following sequence:

VSCode is opened with a file open that looks like a file based program, but is actually part of a solution.
Before the solution loads, Roslyn sees the file and loads it as an FBP. This creates a project in the host workspace for the FBP.
Eventually the solution loads and adds the file to a real project in the solution. At this point in time both the FBP file and the regular file exist in the host solution.
The LspWorkspaceManager attempts to preferentially return the main solution file.
The document pull handler compares the DocumentId from requestContext.Document and requestContext.Solution.GetTextDocumentAsync. Because of 4), these are now different and the handler attempts to report diagnostics for the document and the document as being removed in the same call.

The fix I made here is to remove the document from the misc provider, and re-lookup the document. This ensures the misc document is not part of the solution that is given to the handler. The queue was already blocked on removing the file from misc anyway, so we might as well read that result.

…host document

dibarbet · 2025-10-01T22:50:58Z

@jasonmalinowski @RikkiGibson ptal

src/LanguageServer/Protocol/Extensions/Extensions.cs

...ageServer/Microsoft.CodeAnalysis.LanguageServer.UnitTests/FileBasedProgramsWorkspaceTests.cs

src/LanguageServer/Protocol/Extensions/Extensions.cs

jasonmalinowski · 2025-10-09T23:32:47Z

...ageServer/Microsoft.CodeAnalysis.LanguageServer.UnitTests/FileBasedProgramsWorkspaceTests.cs

+        // The first call should return a document in the misc files workspace.
+        var (_, miscDocument) = await GetLspWorkspaceAndDocumentAsync(newDocumentUri, testLspServer).ConfigureAwait(false);
+        Assert.NotNull(miscDocument);
+        Assert.True(await testLspServer.GetManagerAccessor().IsMiscellaneousFilesDocumentAsync(miscDocument));
+        Assert.Equal(WorkspaceKind.MiscellaneousFiles, miscDocument.Project.Solution.Workspace.Kind);


Is this technically a race if the project system were to load it first? It seems terribly unlikely, but still.

Not currently, no. This is what happens

Nothing happens when the document is opened, the text is just saved.

GetLspWorkspaceAndDocumentAsync searches the workspaces, doesn't find the doc and then calls into the misc provider AddMiscellaneousDocumentAsync.

FBP misc provider creates the 'primordial' document in the misc workspace and triggers the load of the FBP program (adds to the batch).

FBP misc provider always returns the primordial document.

So even if the FBP project load completed instantly, the FBP misc provider still just returns the primordial document from AddMiscellaneousDocumentAsync.

Ah right! Makes sense...does that deserve a comment?

jasonmalinowski

Code change is great; not sure if the test can be unified with another one in the base or moved down to the base, but that's not critical.

jasonmalinowski · 2025-10-09T23:45:32Z

...ageServer/Microsoft.CodeAnalysis.LanguageServer.UnitTests/FileBasedProgramsWorkspaceTests.cs

    }
+
+    [Theory, CombinatorialData]
+    public async Task TestLspTransfersFromFileBasedProgramToHostWorkspaceDocumentOrderingAsync(bool mutatingLspWorkspace)


It's not entirely clear to me how this test is much different than TestLspTransfersFromMiscellaneousFilesToHostWorkspaceAsync test already in the base. I'd expect we should be able to push it to the base class anyways.

src/LanguageServer/Protocol/Workspaces/ILspMiscellaneousFilesWorkspaceProvider.cs

...ageServer/Microsoft.CodeAnalysis.LanguageServer/HostWorkspace/LanguageServerProjectLoader.cs

jasonmalinowski · 2025-10-09T23:54:04Z

...ageServer/Microsoft.CodeAnalysis.LanguageServer.UnitTests/FileBasedProgramsWorkspaceTests.cs

+        // The first call should return a document in the misc files workspace.
+        var (_, miscDocument) = await GetLspWorkspaceAndDocumentAsync(newDocumentUri, testLspServer).ConfigureAwait(false);
+        Assert.NotNull(miscDocument);
+        Assert.True(await testLspServer.GetManagerAccessor().IsMiscellaneousFilesDocumentAsync(miscDocument));
+        Assert.Equal(WorkspaceKind.MiscellaneousFiles, miscDocument.Project.Solution.Workspace.Kind);


Ah right! Makes sense...does that deserve a comment?

Add test demonstrating issue with document context in FBP

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Fix GetTextDocumentAsync returning misc document preferentially over …

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…host document

dibarbet changed the title ~~Add test demonstrating issue with document context in FBP~~ Fix LSP GetTextDocumentAsync returning different document from request context Oct 1, 2025

dibarbet commented Oct 1, 2025

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src/LanguageServer/Protocol/Extensions/Extensions.cs Outdated Show resolved Hide resolved

RikkiGibson self-assigned this Oct 1, 2025