REslava.ResultFlow

RSCG – REslava.ResultFlow    

Generates Mermaid flowchart diagrams at compile time from fluent Result pipeline methods — visualize functional code flows as diagrams

runtime overhead.

How to use

1. Decorate a fluent Result method with [ResultFlow]:

“`charp

[REslava.ResultFlow.ResultFlow]

public static Result GetValueFromConsole()

{

return Result.Ok(value)

.Ensure(s => !string.IsNullOrWhiteSpace(s), new Error(“Input cannot be empty”))

.Map(s => s.ToUpper())

.Tap(s => Console.WriteLine($”Processed: {s}”))

.Ensure(s => int.TryParse(s, out _), new Error(“Input must be a valid integer”))

.Map(s => int.Parse(s));

}

“`

2. Access the generated Mermaid diagram as a compile-time const string:

“`charp

Console.WriteLine(Generated.ResultFlow.Helpers_Flows.GetValueFromConsole);

// outputs a Mermaid flowchart of the pipeline

“`

You can use for Auto-generating up-to-date Mermaid pipeline diagrams from functional Result code at compile time — ideal for documentation, design reviews, or visualizing complex flows without manual diagram maintenance.

This is how you can use REslava.ResultFlow .

The code that you start with is

<project sdk="Microsoft.NET.Sdk">

  <propertygroup>
    <outputtype>Exe</outputtype>
    <targetframework>net10.0</targetframework>
    <implicitusings>enable</implicitusings>
    <nullable>enable</nullable>
  </propertygroup>

  <itemgroup>
    <packagereference version="1.36.0" include="REslava.Result">
    <packagereference version="1.36.0" include="REslava.Result.Analyzers">
      <privateassets>all</privateassets>
      <includeassets>runtime; build; native; contentfiles; analyzers; buildtransitive</includeassets>
    </packagereference>
	<packagereference version="1.36.0" include="REslava.ResultFlow">
		<privateassets>all</privateassets>
		<includeassets>runtime; build; native; contentfiles; analyzers; buildtransitive</includeassets>
	</packagereference>
  </packagereference>
	<propertygroup>
		<emitcompilergeneratedfiles>true</emitcompilergeneratedfiles>
		<compilergeneratedfilesoutputpath>$(BaseIntermediateOutputPath)\GX</compilergeneratedfilesoutputpath>
	</propertygroup>
</itemgroup>

The code that you will use is

// See https://aka.ms/new-console-template for more information
using ResultFlowGenerator;
Console.WriteLine("The mermaid is working!");
Console.WriteLine(Generated.ResultFlow.Helpers_Flows.GetValueFromConsole);
Console.WriteLine("Please enter an int");
var result = Helpers.GetValueFromConsole();
Console.WriteLine(result.IsSuccess
    ? $"You entered: {result.Value}"
    : $"Failed to get a valid integer: {result.Errors.First().Message}");

using REslava.Result;
using REslava.Result.AdvancedPatterns;
using REslava.Result.Extensions;
using System;
using System.Collections.Generic;

namespace ResultFlowGenerator;

internal class Helpers
{
    [REslava.ResultFlow.ResultFlow]
    public static Result<int> GetValueFromConsole()
    {
        var value = Console.ReadLine() ?? "";
        return Result<string>.Ok(value)
            .Ensure(s =&gt; !string.IsNullOrWhiteSpace(s), new Error("Input cannot be empty"))
            .Map(s =&gt; s.ToUpper())
            .Tap(s =&gt; Console.WriteLine($"Processed: {s}"))
            .TapOnFailure(e =&gt; Console.WriteLine($"Error: {e.Message}"))
            .Ensure(s =&gt; int.TryParse(s, out _), new Error("Input must be a valid integer"))
            .Map(s =&gt; int.Parse(s))
            ;


    }
}

   The code that is generated is

// <auto-generated>
// REslava.Result.Flow — auto-generated pipeline diagrams
// Do not edit manually.

namespace Generated.ResultFlow
{
    internal static class Helpers_Flows
    {
        /// <summary>
        /// Mermaid flow diagram for GetValueFromConsole.
        /// Copy into any Mermaid renderer to visualize the pipeline.
        /// </summary>
        public const string GetValueFromConsole = @"
flowchart LR
    N0_Ok[""Ok""]:::operation
    N0_Ok --&gt; N1_Ensure
    N1_Ensure[""Ensure""]:::gatekeeper
    N1_Ensure --&gt;|pass| N2_Map
    N1_Ensure --&gt;|fail| F1[""Failure""]:::failure
    N2_Map[""Map""]:::transform
    N2_Map --&gt; N3_Tap
    N3_Tap[""Tap""]:::sideeffect
    N3_Tap --&gt; N4_TapOnFailure
    N4_TapOnFailure[""TapOnFailure""]:::sideeffect
    N4_TapOnFailure --&gt; N5_Ensure
    N5_Ensure[""Ensure""]:::gatekeeper
    N5_Ensure --&gt;|pass| N6_Map
    N5_Ensure --&gt;|fail| F5[""Failure""]:::failure
    N6_Map[""Map""]:::transform
    classDef operation fill:#e8f4f0,color:#1c7e6f
    classDef gatekeeper fill:#e3e9fa,color:#3f5c9a
    classDef failure fill:#f8e3e3,color:#b13e3e
    classDef transform fill:#e3f0e8,color:#2f7a5c
    classDef sideeffect fill:#fff4d9,color:#b8882c
";

    }
}

// <auto-generated>
using System;

namespace REslava.ResultFlow
{
    /// <summary>
    /// Marks a method for automatic Mermaid flow diagram generation.
    /// Apply to methods that use fluent Result&lt;T&gt; pipeline chains (Bind, Map, Ensure, Tap, Match).
    /// The generated diagram constant is available at Generated.ResultFlow.{ClassName}_Flows.{MethodName}.
    /// </summary>
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
    public sealed class ResultFlowAttribute : Attribute { }
}

Code and pdf at

https://ignatandrei.github.io/RSCG_Examples/v2/docs/REslava.ResultFlow