DI-Loops

DI-Loops is a VS Code extension for .NET developers. It scans dependency injection registrations, builds a constructor-derived dependency graph, and surfaces lifetime mismatches, unregistered dependencies, and duplicate registrations — directly in your editor.

Published by AryaCode Labs.

Why DI-Loops?

ASP.NET Core apps register dozens of services across Program.cs, extension methods, and test projects. Lifetime mistakes (singleton capturing scoped services, trapped transients, duplicate bindings) are easy to miss until runtime.

DI-Loops gives you:

A live registration index in the sidebar
Problems panel diagnostics with click-to-source navigation
CodeLens summaries on AddSingleton / AddScoped lines
An interactive dependency graph webview

Works with regex heuristics out of the box, with optional Roslyn semantic analysis for cross-project accuracy.

Features

Feature	Description
DI Registrations tree	Services grouped by Singleton, Scoped, Transient, and Keyed with pass/warning/error icons
Problems panel	`CAPTURED_SCOPED`, `TRAPPED_TRANSIENT`, `UNREGISTERED`, `DUPLICATE`, and low-confidence variants
CodeLens	Dependency counts and issue summaries above registration lines in `.cs` files
Dependency graph	Interactive vis-network webview — lifetime-colored nodes, mismatch edges (`captured!`, `trapped`)
Incremental scan	Re-scans changed C# files on save (debounced)
Extension methods	Follows `AddApplicationServices()`-style calls into other files under scan scope
Comment-aware regex	Ignores registrations inside `//` and `/* */` comments
Roslyn host (v2)	Optional semantic scanner with regex fallback
Keyed services (v2.5)	`AddKeyed` / `TryAddKeyed` parsing with separate registry dimension

Detected registration patterns

AddSingleton<T>(), AddScoped<T, TImpl>(), TryAddTransient<...>()
Lambda factories: AddSingleton<T>(sp => new T())
Instance arguments: AddSingleton<IConfiguration>(configuration)
services.Replace(ServiceDescriptor.Scoped<...>()) (configurable)
Keyed: AddKeyedSingleton<T, TImpl>("key") when enableKeyed is on

Issue rules

Issue	Severity	Rule
Captured scoped	Error	Singleton directly depends on a scoped service
Trapped transient	Warning	Singleton directly depends on a transient service
Unregistered	Error	Constructor dependency not found in registry
Duplicate	Warning	Same service type registered more than once (per key)

Installation

VS Code Marketplace

Open Extensions (Ctrl+Shift+X / Cmd+Shift+X)
Search for DI-Loops
Click Install

Or install from the command line:

code --install-extension AryaCodeLabs.di-container-mapper

The extension ID uses the internal package name di-container-mapper; the display name in the UI is DI-Loops.

From source

git clone https://github.com/aryacodelabs/di-loops.git
cd di-loops
npm install
npm run build:roslyn   # optional, for Roslyn mode
npm run build
npm run package        # produces .vsix
code --install-extension di-container-mapper-*.vsix

Requirements: VS Code ^1.85.0, Node.js 20+, .NET 8 SDK (Roslyn host only).

Quick start

Open a folder containing a .csproj or .sln
Run DI-Loops: Map DI Container from the Command Palette (Ctrl+Shift+P)
Open the DI Registrations view in the Explorer sidebar
Click a registration to jump to source, or right-click → Show Dependency Graph

The status bar shows registration count, issue summary, and scanner mode (heuristic or roslyn).

Recommended settings (multi-project solution)

{
  "diContainerMapper.projectPath": "src/MyApp",
  "diContainerMapper.excludeTestProjects": true,
  "diContainerMapper.scanOnSave": true
}

Roslyn mode (higher accuracy)

{
  "diContainerMapper.useRoslyn": true,
  "diContainerMapper.roslynHostPath": ""
}

Build the host once: npm run build:roslyn. If the host is missing or fails, DI-Loops falls back to regex automatically.

Keyed services (.NET 8+)

{
  "diContainerMapper.enableKeyed": true
}

Keyed registrations appear under the Keyed tree group and use registry keys like ICache@primary.

Commands

Command	Description
`DI-Loops: Map DI Container`	Full workspace scan
`DI-Loops: Refresh DI Index`	Re-resolve scope and rescan
`DI-Loops: Show DI Dependencies`	Editor context menu — graph for class at caret
`DI-Loops: Show Dependency Graph`	Tree context menu — graph for selected registration
`DI-Loops: Go to Registration`	Navigate to registration source

Settings

Setting	Default	Description
`diContainerMapper.projectPath`	`""`	Limit scanning to a specific project folder
`diContainerMapper.scanEntireSolution`	`false`	Scan all projects under a `.sln`
`diContainerMapper.scanOnSave`	`true`	Re-scan changed C# files on save
`diContainerMapper.enableWebview`	`true`	Enable the interactive dependency graph
`diContainerMapper.useRoslyn`	`false`	Use Roslyn semantic analysis
`diContainerMapper.roslynHostPath`	`""`	Override path to the RoslynHost binary
`diContainerMapper.includeServiceDescriptorReplace`	`true`	Detect `ServiceDescriptor.Replace` calls
`diContainerMapper.excludeTestProjects`	`true`	Skip `Tests`, `UnitTest`, etc.
`diContainerMapper.enableKeyed`	`false`	Parse `AddKeyed*` registrations

Configure via File → Preferences → Settings and search for DI-Loops or diContainerMapper.

Scope resolution

When projectPath is empty, DI-Loops picks scan scope automatically:

projectPath setting (if set)
Startup project under the first .sln (skips Demo/Test/Sample projects)
Whole solution folder (only when scanEntireSolution is true)
Shallowest Program.cs / Startup.cs
First .csproj folder

For large solutions, open the app project folder or set projectPath to avoid cross-project false duplicates.

Development

npm install
npm run build:roslyn
npm run build
npm test
npm run lint

Press F5 in VS Code to launch the Extension Development Host.

npm run package   # create .vsix for local install or marketplace upload

Contributing

Issues and pull requests are welcome at github.com/aryacodelabs/di-loops.

See CHANGELOG.md for release history.

License

MIT — see LICENSE.