Use vscode-uri semantics for parsing URIs by dibarbet · Pull Request #83593 · dotnet/roslyn

dibarbet · 2026-05-06T21:47:47Z

We've had a number of issues with using System.Uri over the years, mostly caused by VSCode's URI handling being more lenient than System.Uri (and System.Uri being more strict than even the URI RFC requires). Most recently is dotnet/vscode-csharp#9087 which this should resolve.

There've been a number of fixes, including implementing our own equality checks, delaying URI parsing until we absolutely require it, and others - but none have been perfect - we continually see System.Uri parsing failures.

The goal of this PR is to switch to VSCode's URI parsing behavior (from vscode-uri) and avoid using System.Uri altogether due to the number of issues we've had. This should ensure that any URI we get from VSCode we can parse.

Mostly - this is a server-side behavior change. However this is visible to clients as this does change how we convert a URI into a string for serialization. These now serialize using vscode-uri semantics, so things like drive letters will get encoded (c:/ -> file:///c%3A/). System.Uri left the colon in the drive letter unencoded in the URI string.

We also cannot entirely delete System.Uri handling from the LSP path yet - XAML EA APIs and various parts of Razor still rely on System.Uri - however we can limit usage to just those scenarios.

The implementation of ParsedUri is intended to match vscode-uri. For examples and details on how URIs are parsed, how they are equal, and how they round trip, see ParsedUriTests.

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dibarbet · 2026-07-20T23:48:54Z

/pr-val

github-actions · 2026-07-20T23:49:25Z

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Validation Type: pr-val
Pipeline ID: 8972
Pipeline Version: main
PR Number: 83593
Commit SHA: a20777cd6c4ebd14ed49ff310e324d0b7052135c
Source Branch: vscode-uri
Target Branch: main
Build ID: 14714249

azure-pipelines · 2026-07-22T17:33:53Z

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github-actions · 2026-08-26T18:41:28Z

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Validation Type: pr-val
Pipeline ID: 8972
Pipeline Version: main
PR Number: 83593
Commit SHA: e75762d8b68f54ab703af4aee8980847b24b7c4d
Source Branch: vscode-uri
Target Branch: main
Build ID: 15108206

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 17dcbb0d-711d-4cca-91c3-574ec31aeea8

dibarbet · 2026-08-28T00:30:54Z

/pr-val

github-actions · 2026-08-28T00:31:25Z

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Validation Type: pr-val
Pipeline ID: 8972
Pipeline Version: main
PR Number: 83593
Commit SHA: 9eb6d8ddce85c92726567f9607b557793682adcd
Source Branch: vscode-uri
Target Branch: main
Build ID: 15127059

Copilot

Copilot review overview

Review tier: Lite
Findings: 1 · 4

New issues introduced by this change (2)

Severity	Finding
	`src/LanguageServer/Protocol/Protocol/DocumentUri.cs` — The XML doc references `Protocol.ParsedUri`, but there is no `Protocol` alias/type/namespace here;…
	`src/LanguageServer/Protocol/Extensions/Extensions.cs` — Project file path comparisons should be OS-sensitive. Using `StringComparison.OrdinalIgnoreCase`…

Pre-existing issues (3)

Severity	Finding
	`src/LanguageServer/Protocol/Protocol/ParsedUri.cs` — `s_singleSlashStart` and `s_doubleSlashStart` are declared but never used in this port. If they’re… View comment
	`src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/UriExtensions.cs` — These `#pragma warning disable` comments include "TODO" text. This repo’s guidance is to avoid… View comment
	`src/LanguageServer/Protocol/Protocol/DocumentUri.cs` — `DocumentUri(Uri)` no longer seeds the cached parsed representation, so the first access to… View comment

Issues resolved since last review (1)

Severity	Finding
	`src/LanguageServer/BannedSymbols.txt` — This PR introduces a new core URI abstraction (`ParsedUri`) and also adds a new repo-level rule… View resolved comment

Suppressed comments (2)

src/LanguageServer/Protocol/Protocol/DocumentUri.cs:49

Protocol.ParsedUri.Parse(...) looks like an accidental qualification; there is no Protocol alias/type here. This should call ParsedUri.Parse(...) directly or it won’t compile.
src/LanguageServer/Protocol/Protocol/DocumentUri.cs:67
Obsolete message says "Use ParsedDocUri instead" but the property is named ParsedDocumentUri. The message should match the API name to avoid confusion during migrations.

Copilot

Copilot review overview

Review tier: Lite
Findings: 1 · 3

New issues introduced by this change (1)

Severity	Finding
	`src/LanguageServer/Protocol/Extensions/Extensions.cs` — GetRequiredLegacySystemUri calls the obsolete DocumentUri.ParsedUri without suppressing CS0618…

Pre-existing issues (3)

Severity	Finding
	`src/LanguageServer/Protocol/Protocol/ParsedUri.cs` — `s_singleSlashStart` and `s_doubleSlashStart` are declared but never used in this port. If they’re… View comment
	`src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/UriExtensions.cs` — These `#pragma warning disable` comments include "TODO" text. This repo’s guidance is to avoid… View comment
	`src/LanguageServer/Protocol/Protocol/DocumentUri.cs` — `DocumentUri(Uri)` no longer seeds the cached parsed representation, so the first access to… View comment

Issues resolved since last review (2)

Severity	Finding
	`src/LanguageServer/Protocol/Extensions/Extensions.cs` — Project file path comparisons should be OS-sensitive. Using `StringComparison.OrdinalIgnoreCase`… View resolved comment
	`src/LanguageServer/Protocol/Protocol/DocumentUri.cs` — The XML doc references `Protocol.ParsedUri`, but there is no `Protocol` alias/type/namespace here;… View resolved comment

Suppressed comments (3)

src/LanguageServer/Protocol/Protocol/DocumentUri.cs:68

The Obsolete message references "ParsedDocUri", but the property is now named ParsedDocumentUri. This reads like a typo and makes guidance to callers unclear.
src/LanguageServer/Protocol/Extensions/Extensions.cs:228
GetProject now compares project.FilePath to the request URI path using OrdinalIgnoreCase unconditionally. That can produce incorrect matches on case-sensitive file systems (Linux/macOS) and differs from Roslyn’s established path comparison behavior. Use PathUtilities.Comparer (OS-appropriate) instead.

    public static Project? GetProject(this Solution solution, TextDocumentIdentifier projectIdentifier)
    {
        // We need to parse the URI (scheme, file path) to be able to lookup the URI in the solution.
        var parsedDocumentUri = projectIdentifier.DocumentUri.ParsedDocumentUri;
        if (parsedDocumentUri is null)
        {
            return null;
        }

        var projects = solution.Projects.WhereAsArray(project => string.Equals(project.FilePath, parsedDocumentUri.FsPath, StringComparison.OrdinalIgnoreCase));
        return !projects.Any()

src/LanguageServer/Protocol/Extensions/ProtocolConversions.cs:635

HelpLinkToCodeDescription now wraps any non-null string into a DocumentUri without validating that it’s an absolute URI. This is a behavior change from the prior Uri.TryCreate-based validation (via DiagnosticData.GetValidHelpLinkUri) and can accidentally emit invalid/empty href values (e.g., empty string becomes a parsed file URI under non-strict parsing). Consider validating with ParsedUri (strict for URLs, and ParsedUri.File for absolute file paths) and returning null on parse failure.

    public static LSP.CodeDescription? HelpLinkToCodeDescription(string? helpLinkUri)
    {
        return (helpLinkUri != null) ? new LSP.CodeDescription { Href = new DocumentUri(helpLinkUri) } : null;
    }

+#pragma warning disable RS0030 // Intentional for backwards compatibility.
+        var parsedUri = documentUri.ParsedUri;
+        Contract.ThrowIfNull(parsedUri, $"URI {documentUri} could not be parsed");
+#pragma warning restore RS0030 // Do not use banned APIs
+        return parsedUri;


Copilot

Copilot review overview

🟡 Changes recommended

It introduces at least one correctness issue in path comparison (OrdinalIgnoreCase instead of PathUtilities.Comparer) and contains misleading obsolete guidance text that should be fixed before merge.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review tier: Lite
Findings: 1 · 1 · 4

New issues introduced by this change (2)

Severity	Finding
	`src/LanguageServer/Protocol/Extensions/Extensions.cs` — `GetProject` compares `project.FilePath` to `parsedDocumentUri.FsPath` using…
	`src/LanguageServer/Protocol/Protocol/DocumentUri.cs` — The `[Obsolete]` message for `ParsedUri` says "Use ParsedDocUri instead", but the property is named…

Pre-existing issues (4)

Severity	Finding
	`src/LanguageServer/Protocol/Extensions/Extensions.cs` — GetRequiredLegacySystemUri calls the obsolete DocumentUri.ParsedUri without suppressing CS0618… View comment
	`src/LanguageServer/Protocol/Protocol/ParsedUri.cs` — `s_singleSlashStart` and `s_doubleSlashStart` are declared but never used in this port. If they’re… View comment
	`src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/UriExtensions.cs` — These `#pragma warning disable` comments include "TODO" text. This repo’s guidance is to avoid… View comment
	`src/LanguageServer/Protocol/Protocol/DocumentUri.cs` — `DocumentUri(Uri)` no longer seeds the cached parsed representation, so the first access to… View comment

    public static Project? GetProject(this Solution solution, TextDocumentIdentifier projectIdentifier)
    {
        // We need to parse the URI (scheme, file path) to be able to lookup the URI in the solution.
-        if (projectIdentifier.DocumentUri.ParsedUri is null)
+        var parsedDocumentUri = projectIdentifier.DocumentUri.ParsedDocumentUri;
+        if (parsedDocumentUri is null)
        {
            return null;
        }

-        var projects = solution.Projects.WhereAsArray(project => project.FilePath == projectIdentifier.DocumentUri.ParsedUri.LocalPath);
+        var projects = solution.Projects.WhereAsArray(project => string.Equals(project.FilePath, parsedDocumentUri.FsPath, StringComparison.OrdinalIgnoreCase));
        return !projects.Any()
            ? null
            : FindItemInProjectContext(projects, projectIdentifier, projectIdGetter: (item) => item.Id, defaultGetter: () => projects[0]);


+    [Obsolete("Use ParsedDocUri instead. Tracking: https://github.com/dotnet/roslyn/issues/84785")]
+    public Uri? ParsedUri


Copilot

Copilot review overview

🔵 Needs a closer look

It introduces an OS-inappropriate case-insensitive project path comparison and contains a misleading Obsolete message that should be corrected.

Review tier: Lite
Findings: 1 · 1 · 4

Pre-existing issues (6)

Severity	Finding
	`src/LanguageServer/Protocol/Extensions/Extensions.cs` — GetRequiredLegacySystemUri calls the obsolete DocumentUri.ParsedUri without suppressing CS0618… View comment
	`src/LanguageServer/Protocol/Extensions/Extensions.cs` — `GetProject` compares `project.FilePath` to `parsedDocumentUri.FsPath` using… View comment
	`src/LanguageServer/Protocol/Protocol/DocumentUri.cs` — The `[Obsolete]` message for `ParsedUri` says "Use ParsedDocUri instead", but the property is named… View comment
	`src/LanguageServer/Protocol/Protocol/ParsedUri.cs` — `s_singleSlashStart` and `s_doubleSlashStart` are declared but never used in this port. If they’re… View comment
	`src/Razor/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/UriExtensions.cs` — These `#pragma warning disable` comments include "TODO" text. This repo’s guidance is to avoid… View comment
	`src/LanguageServer/Protocol/Protocol/DocumentUri.cs` — `DocumentUri(Uri)` no longer seeds the cached parsed representation, so the first access to… View comment

Suppressed comments (2)

src/LanguageServer/Protocol/Protocol/DocumentUri.cs:68

The Obsolete message refers to "ParsedDocUri", but the property is named ParsedDocumentUri. This makes the guidance misleading for callers.
src/LanguageServer/Protocol/Extensions/Extensions.cs:228
Project file paths are compared using OrdinalIgnoreCase unconditionally. On Unix-like platforms this can incorrectly match the wrong project when paths differ only by casing; Roslyn generally uses PathUtilities.Comparer for path equality to respect platform semantics.

            return null;
        }

        var projects = solution.Projects.WhereAsArray(project => string.Equals(project.FilePath, parsedDocumentUri.FsPath, StringComparison.OrdinalIgnoreCase));
        return !projects.Any()

github-actions Bot added the Area-Infrastructure label May 6, 2026

dotnet-policy-service Bot added the VSCode label May 6, 2026

dibarbet force-pushed the vscode-uri branch 2 times, most recently from 9ca5e2b to 761fca8 Compare May 7, 2026 22:31

build-analysis Bot mentioned this pull request May 8, 2026

[Known Build Error] VSIXInstaller.exe failed to execute #83287

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dibarbet force-pushed the vscode-uri branch 2 times, most recently from 9eb64f0 to 8d6c2d0 Compare May 12, 2026 17:43

dotnet-policy-service Bot added the Area-Razor label May 12, 2026

dibarbet force-pushed the vscode-uri branch from 8d6c2d0 to 06417d4 Compare May 20, 2026 22:34

dibarbet force-pushed the vscode-uri branch 3 times, most recently from 9a8a978 to d9118a9 Compare June 16, 2026 02:36

dibarbet force-pushed the vscode-uri branch 2 times, most recently from df6903b to ea4a4b5 Compare June 24, 2026 22:53

dibarbet force-pushed the vscode-uri branch 2 times, most recently from c9ba792 to 18cd21a Compare July 20, 2026 20:19

dibarbet changed the title ~~wip~~ Use vscode-uri semantics for parsing URIs Jul 20, 2026

dibarbet force-pushed the vscode-uri branch 2 times, most recently from cdef7e6 to a20777c Compare July 20, 2026 23:28

dibarbet force-pushed the vscode-uri branch 2 times, most recently from 4e61e5f to b2c8d49 Compare July 21, 2026 23:25

build-analysis Bot mentioned this pull request Jul 22, 2026

[Known Build Error] Test_Windows_Desktop_Release_32: Test host process crashed #84579

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dibarbet marked this pull request as ready for review July 22, 2026 17:33

Copilot AI lite review requested due to automatic review settings July 22, 2026 17:33

dibarbet requested review from a team as code owners July 22, 2026 17:33

Copilot started reviewing on behalf of dibarbet July 22, 2026 17:34 View session

dibarbet added 4 commits August 27, 2026 16:18

review feedback

1b9efcd

Merge remote-tracking branch 'upstream/main' into vscode-uri

d2bec4b

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 17dcbb0d-711d-4cca-91c3-574ec31aeea8

Merge remote-tracking branch 'upstream/main' into vscode-uri

0ab110f

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 17dcbb0d-711d-4cca-91c3-574ec31aeea8

address new uri usages from merge

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Comment thread src/LanguageServer/Protocol/Protocol/DocumentUri.cs

Comment thread src/LanguageServer/Protocol/Extensions/Extensions.cs

fix new razor uri usages

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Merge branch 'main' into vscode-uri

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JoeRobich approved these changes Sep 2, 2026

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fix test from merge

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dibarbet merged commit d6d58d3 into dotnet:main Sep 2, 2026
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This was referenced Sep 3, 2026

[main] Source code updates from dotnet/roslyn dotnet/dotnet#8994

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[release/11.0.1xx] Source code updates from dotnet/roslyn dotnet/dotnet#9006

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dotnet-bot mentioned this pull request Sep 4, 2026

[Automated] PRs inserted in VS build main-12203.181 #85159

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dibarbet mentioned this pull request Sep 4, 2026

Update roslyn to 5.12.0-1.26453.19 dotnet/vscode-csharp#9731

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Use vscode-uri semantics for parsing URIs - #83593

Use vscode-uri semantics for parsing URIs#83593
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		[Obsolete("Use ParsedDocUri instead. Tracking: https://github.com/dotnet/roslyn/issues/84785")]
		public Uri? ParsedUri

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dibarbet commented May 6, 2026 •

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