CodeGraphToDgml

Code Graph to DGML is a Visual Studio extension that builds DGML graphs from the symbol at the editor caret.

Building and maintaining this took real ideation, time, design effort, and compute (including LLM usage) to get right. If it's useful to you, consider sponsoring its development — any amount helps keep it going. 💛

Features

Traverse Up to DGML

• traverses callers upward from C# and Visual Basic methods, properties, and events
• limits traversal by maximum depth and node count
• filters properties, events, external symbols, and generated code
• discovers forms, pages, and windows that host UI components (WinForms, WebForms, WPF, Blazor, MAUI, Avalonia) and adds them with UsedBy links
• follows nested component hosting up to a configurable depth

Traverse Down to DGML

• traverses callees downward from C# and Visual Basic methods, properties, and events (VB call sites include parenless calls, Call, RaiseEvent, AddHandler/RemoveHandler, AddressOf, With blocks, and From/With initializers)
• follows interface implementations (Implements links) and virtual/abstract overrides in derived types (Overrides links) so the graph reflects the methods that may actually run at each call site
• limits traversal by maximum depth and node count
• filters properties, events, external symbols, and generated code

All References to DGML

• mirrors Visual Studio's built-in Find All References (Shift+F12) for the symbol at the caret
• supports C# and Visual Basic types (class, struct, interface, record) and members (methods, properties, events, fields)
• adds a References link from each enclosing referrer (method, property, event, field, or type) to the target symbol
• limits the result by maximum node count and respects the external symbol and generated code filters (references are a single level, so maximum depth does not apply)

Traverse Down to Sequence Diagram (with Control Flow)

• same traversal as the command above, rendered with Mermaid combined fragments so the diagram shows when each call happens
• if / else if / else, switch statements and expressions, and ?: become alt sections (an if whose other branches make no calls becomes opt)
• for, foreach, while, and do become loop; catch clauses become break; try bodies, finally, using, lock, lambdas, and ?. are transparent
• a call inside a condition (if (Check())) is placed before the fragment, since it runs before the branch is chosen
• an interface member or virtual method with several implementations renders as one alt with a branch per implementing type
• the same callee reached from two branches appears once per branch; a fragment cut by the diagram splitter is re-opened in the next part with a (cont.) marker
• fragment labels are truncated to Max condition label length (default 40)
• Visual Basic: If/ElseIf/Else, single-line If, Select Case, If(a, b, c), For/For Each/While/Do loops, and Catch blocks map the same way
• output files are named CodeSequenceFlow-{timestamp}.md / .html

Common

• appends to or replaces an open DGML document
• creates a new DGML document under {SolutionDir}\.vs\CodeGraphToDgml\ when no target document is open (falls back to %TEMP% without a solution)
• reports progress in the status bar and a cancellable modal dialog
• writes execution details to a dedicated Output window pane

Prerequisites

The DGML editor is included by default in Visual Studio Enterprise. For Community or Professional editions it must be installed separately:

1. Open Visual Studio Installer.
2. Click Modify on your Visual Studio installation.
3. Switch to the Individual components tab.
4. Search for DGML editor.
5. Check the component and click Modify to install it.

Without the DGML editor, Visual Studio cannot open or display .dgml files generated by this extension.

Solution Layout

• src/CodeGraphToDgml.Core: dependency-free graph model, DGML serializer, and Mermaid sequence serializer
• src/CodeGraphToDgml.Roslyn: host-free Roslyn call-site detection, filters, and dispatch resolution (testable without Visual Studio)
• src/CodeGraphToDgml.Vsix: Visual Studio host integration, commands, options, and the traversal providers
• tests/CodeGraphToDgml.Tests: MSTest unit tests for the Core and Roslyn projects

Build

Build the extension from the Release configuration to produce the VSIX package:

dotnet build .\CodeGraphToDgml.sln -c Release

The repository includes both CodeGraphToDgml.sln and CodeGraphToDgml.slnx.

The generated VSIX is written to src\CodeGraphToDgml.Vsix\bin\Release\net48\CodeGraphToDgml.Vsix.vsix.

All projects are SDK-style, including the VSIX project (VSSDKBuildToolsAutoSetup), and package versions are managed centrally in Directory.Packages.props.

Versioning

The extension version lives in one place: <Version> in Directory.Build.props. The VSIX manifest resolves it at build time through the |%CurrentProject%;GetVsixVersion| placeholder, and Vsix.Version is generated into obj\Vsix.Version.g.cs. To release, bump that single value and tag the commit.

Release

The Build workflow runs on every push and pull request (build, tests, VSIX artifact, and a check that the packaged manifest version equals Directory.Build.props). Pushing a tag vX.Y.Z additionally:

1. verifies the tag matches Directory.Build.props,
2. creates a GitHub release with the VSIX attached, and
3. waits for approval on the marketplace environment, then publishes the VSIX to the Visual Studio Marketplace with VsixPublisher.exe using publishManifest.json.

One-time setup on GitHub:

• Create the marketplace environment (Settings > Environments) and add yourself as a required reviewer so publishing needs an explicit approval.
• Add the secret VS_MARKETPLACE_PAT (Settings > Secrets and variables > Actions). Its value is an Azure DevOps personal access token: sign in at https://dev.azure.com, open User settings > Personal access tokens > New token, choose Organization "All accessible organizations", Scopes "Custom defined" with Marketplace: Publish (or Manage), and copy the token. The account must be a member of the guerchele publisher at https://marketplace.visualstudio.com/manage.

Manual Test Matrix