REslava.Result.Flow 1.49.0

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.

The recommended pipeline visualization package for REslava.Result projects. Generates Mermaid diagrams with full type travel, typed error edges from method body scanning, and entry-point detection — all via Roslyn semantic analysis.

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

Using a different Result library (ErrorOr, LanguageExt, FluentResults)? Use REslava.ResultFlow — the library-agnostic alternative instead.

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

Diagnostics

Documentation

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

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