Invex.StructuredText

A strongly-typed C# library for generating structured YAML text files, specifically GitHub Actions workflows, Dependabot configurations, and Azure DevOps Pipelines, using a fluent, type-safe API with a powerful expression system.

Features

Type-safe workflow authoring

Define CI/CD pipelines as C# objects with full IntelliSense and compile-time validation

Unified expression system

Build complex expressions (conditions, string interpolation, functions) that compile to platform-specific syntax

GitHub Actions

Full support for workflow YAML generation including triggers, jobs, steps, matrix strategies, permissions, concurrency, containers, and more

Dependabot

Generate dependabot.yml configurations with registries, update rules, groups, and schedules

Azure DevOps Pipelines

Comprehensive pipeline generation with stages, jobs, deployment strategies (runOnce, rolling, canary), resources, templates, and parameters

Packages

Package	Description
Invex.StructuredText	Core library with StructuredTextWriter and the expression system
Invex.StructuredText.GithubActions	GitHub Actions workflow and Dependabot config generation
Invex.StructuredText.AzureDevopsPipelines	Azure DevOps Pipelines YAML generation

Installation

dotnet add package Invex.StructuredText.GithubActions
# or
dotnet add package Invex.StructuredText.AzureDevopsPipelines

Both platform packages depend on Invex.StructuredText core, so it will be installed automatically.

Documentation

Comprehensive guides live in the docs/ directory:

• Introduction — what this library is and why it exists
• Getting Started — install and generate your first file
• Expressions — the unified expression system
• GitHub Actions — workflow generation in depth
• Dependabot — dependabot.yml generation
• Azure DevOps Pipelines — pipelines, stages, jobs, deployment strategies
• Architecture — how the pieces fit together
• FAQ

An auto-generated API reference is built with docfx from the XML documentation comments.

Quick Start

GitHub Actions

var workflow = new GithubAction
{
    Name = "CI",
    On =
    [
        new On.Push
        {
            Branches = ["main"],
            BranchesIgnore = null,
            Tags = null,
            TagsIgnore = null,
            Paths = null,
            PathsIgnore = null,
        },
    ],
    Jobs =
    [
        new Job
        {
            Name = new RawExpression("build"),
            RunsOn = new() { Labels = [new RawExpression("ubuntu-latest")] },
            Steps =
            [
                new Step.UsesStep
                {
                    Name = new RawExpression("Checkout"),
                    Uses = new RawExpression("actions/checkout@v4"),
                },
                new Step.RunStep
                {
                    Name = new RawExpression("Build"),
                    Run = ["dotnet build --configuration Release"],
                },
            ],
        },
    ],
};

var writer = new GithubActionWriter();
writer.Write(workflow);

var yaml = writer.TextWriter.ToString();

Azure DevOps Pipelines

var pipeline = new DevopsPipeline.DevopsPipelineWithSteps
{
    Trigger = new Trigger.BranchList { Branches = ["main"] },
    Steps =
    [
        new Step.Script { ScriptContent = new RawExpression("echo Hello, world!") },
    ],
};

var writer = new DevopsPipelineWriter();
writer.Write(pipeline);

var yaml = writer.TextWriter.ToString();

Expressions

The expression system provides a fluent API for building platform-specific expressions that are formatted differently depending on the target (GitHub Actions uses ${{ }} syntax, Azure DevOps uses its own macro/runtime expression syntax).

// Reference step outputs
var output = new StepOutputExpression
{
    StepName = "build-step",
    OutputName = "artifact-path",
};

// Use conditions
var condition = output.Contains("release").Evaluate();

// String interpolation with format expressions
var formatted = TextExpressions.Format($"Release-{output}");

// Logic operators
var combined = output.Contains("main") & new BooleanExpression(true);

Architecture

Core (Invex.StructuredText)

• StructuredTextWriter: A low-level indentation-aware text writer that handles YAML-style output with automatic indent management via IDisposable scopes
• Expression System: A rich set of record types (TextExpression hierarchy) representing values, functions, logic operators, and workflow-specific constructs (step outputs, job outcomes, etc.)
• TextExpressionFormatter: Base class for platform-specific expression formatters

GitHub Actions (Invex.StructuredText.GithubActions)

• GithubActionWriter: Serializes a GithubAction model to valid workflow YAML
• DependabotConfigWriter: Serializes a DependabotConfig model to valid dependabot.yml
• GithubExpressionFormatter: Formats expressions using GitHub's ${{ }} syntax
• Model types: Strongly-typed records for all GitHub Actions concepts (triggers, jobs, steps, matrix, permissions, etc.)

Azure DevOps Pipelines (Invex.StructuredText.AzureDevopsPipelines)

• DevopsPipelineWriter: Serializes a DevopsPipeline model to valid pipeline YAML
• DevopsExpressionFormatter: Formats expressions using Azure DevOps syntax
• Model types: Strongly-typed records/unions for pipelines, stages, jobs, steps, resources, triggers, variables, deployment strategies, and more

Requirements

• .NET 8.0, .NET 9.0, or .NET 10.0

License

This project is licensed under the MIT License.