REslava.Result.Flow 1.54.0

REslava.Result.Flow

Visual Result pipelines for .NET — typed errors, Railway-Oriented pipelines, automatic flow diagrams.

Don't try to understand the pipeline—watch the flow.

Track A — Pipeline visualization for REslava.Result projects.

Full semantic analysis via Roslyn: typed error edges from method body scanning, IResultBase<T> type travel, FAIL node error annotation, and the complete diagram constant set — _Diagram, _TypeFlow, _LayerView, _Stats, _ErrorSurface, _ErrorPropagation.

Not using REslava.Result? Use Track B — REslava.ResultFlow — the library-agnostic, syntax-only alternative that works with ErrorOr, LanguageExt, FluentResults, or any custom Result type.

Generated Diagram Examples

Pipeline — full type travel, typed error edges, cross-method subgraph expansion:

Architecture layer view — Domain / Application / Infrastructure boundaries:

Error propagation — errors grouped by the layer they originate from:

Match — hexagon node with typed N-branch fan-out:

Node type legend — all 9 node types with colors, shapes, and hover tooltip note:

Dark theme — [ResultFlow(Theme = ResultFlowTheme.Dark)] emits the full diagram set using a dark colour scheme:

→ Full diagram gallery and documentation on GitHub

Installation

dotnet add package REslava.Result.Flow

Requires REslava.Result in your project. The [ResultFlow] attribute is injected automatically — no extra using needed.

What it does

Add [ResultFlow] to any REslava.Result fluent method and the generator produces:

• Success type travel — inferred from IResultBase<T> at each step; type-preserving steps show "MethodName<br/>T"; type-changing steps show "MethodName<br/>T → U"
• Error surface — scans method bodies of Bind/Ensure delegates for error construction, annotates failure edges with specific error types
• Async step annotation — ⚡ appended to any step that resolves via await

Quick Start

[ResultFlow]
public async Task<Result<UserDto>> RegisterAsync(RegisterCommand cmd) =>
    await CreateUser(cmd)
        .EnsureAsync(IsEmailValid, new InvalidEmailError())
        .BindAsync(SaveUser)
        .TapAsync(SendWelcomeEmail)
        .MapAsync(ToDto);

Use the IDE code action (REF002 — "Insert diagram as comment") to inject the diagram directly above the method — no build required:

/*
```mermaid
flowchart LR
    N0_EnsureAsync["EnsureAsync ⚡<br/>User"]:::gatekeeper
    N0_EnsureAsync -->|pass| N1_BindAsync
    N0_EnsureAsync -->|fail| FAIL
    ...
```*/
[ResultFlow]
public async Task<Result<UserDto>> RegisterAsync(RegisterCommand cmd) => ...

The ```mermaid fence makes the diagram render inline in VS Code, GitHub, Rider, and other Markdown-aware IDEs.

Diagram Preview — VS Code Extension (v1.1.0)

Install REslava.Result Extensions from the VS Code Marketplace to get a ▶ Open diagram preview CodeLens above every [ResultFlow] method.

One click opens the rendered Mermaid diagram in a dedicated side panel — bundled renderer, works fully offline.

Panel features:

• Click any node to navigate to that line in your source (requires <ResultFlowLinkMode>vscode</ResultFlowLinkMode> in your .csproj)
• Source button — view and copy the raw Mermaid DSL
• Legend button — node colour guide and interaction hints
• SVG / PNG buttons — export the diagram to disk (PNG at 2× for high-DPI screens)
• Light and dark background follows your ResultFlowDefaultTheme MSBuild property

Solution-Wide Default Theme (v1.48.0)

Set a diagram theme for the whole solution in Directory.Build.props — no need to annotate every method:

<PropertyGroup>
  <ResultFlowDefaultTheme>Dark</ResultFlowDefaultTheme>
</PropertyGroup>

Per-method [ResultFlow(Theme = ResultFlowTheme.Dark)] always overrides the MSBuild default. Accepted values: Light (default), Dark.

Compared to REslava.ResultFlow, this package adds:

• Typed failure edges (e.g. InvalidEmailError instead of just fail)
• Error surface inference via IError — no manual annotation required

Debug Panel — ▶ Debug CodeLens (v1.53.0)

Make your class partial to unlock the FlowProxy — a generated wrapper that feeds the VS Code Debug panel with zero setup.

// Mark your class partial:
public partial class OrderService
{
    [ResultFlow]
    public Result<Order> Process(int userId, int productId) => ...
}

// Always-on tracing (full ring buffer — many methods, many calls):
var result = svc.Flow.Process(userId, productId);
ringBuffer.Save();   // → reslava-traces.json in bin/ — VSIX auto-loads

// Single-trace debug (one method, one execution):
svc.Flow.Debug.Process(userId, productId);
// → reslava-debug-Process.json saved automatically
// → VSIX file watcher fires → Debug panel opens with the trace

The Debug panel shows a trace list, node stepper, animated replay with diagram node highlight, and a file picker when multiple reslava-*.json files are present.

Advanced: For long-running or remote scenarios, add REslava.Result.Diagnostics to expose traces over HTTP (PipelineTraceHost.Start / MapResultFlowTraces).

Diagnostics

Documentation

Full documentation: reslava.github.io/nuget-package-reslava-result

MIT License | Works with any .NET project (netstandard2.0)