elsa-core/.github/copilot-instructions.md

Copilot Coding Agent Instructions for Elsa Workflows

Repository Overview

Elsa Workflows is a powerful .NET workflow library that enables workflow execution within any .NET application. This is version 3.0, supporting .NET 9.0 and providing both a visual designer and programmatic workflow definition capabilities.

Key Statistics

• Language: C# (.NET 9.0)
• Architecture: Modular library with 104+ projects
• Code Size: ~3,500 C# files across modules
• License: MIT
• Build System: NUKE build automation
• Target Frameworks: .NET 9.0 (primary)

High-Level Architecture

Directory Structure

src/
├── apps/               # Reference applications (5 projects)
│   ├── Elsa.Server.Web            # Workflow server only
│   ├── Elsa.ServerAndStudio.Web    # Combined server + studio  
│   ├── Elsa.Studio.Web             # Studio web interface
│   ├── ElsaStudioWebAssembly       # Studio WebAssembly app
│   └── Elsa.Server.LoadBalancer    # Load balancer
├── common/             # Shared libraries (8 projects)
├── modules/            # Core functionality modules (70+ projects)
│   ├── Elsa.Workflows.Core         # Core workflow engine
│   ├── Elsa.Workflows.Runtime      # Runtime execution
│   ├── Elsa.Workflows.Api          # REST API
│   ├── Elsa.Http                   # HTTP activities
│   ├── Elsa.Email                  # Email activities
│   └── [many others]               # Database, messaging, etc.
└── clients/            # API clients
test/
├── unit/               # Unit tests
├── integration/        # Integration tests  
├── component/          # Component tests
└── performance/        # Performance tests
build/                  # NUKE build configuration
docker/                 # Docker configurations

Core Components

• Elsa.Workflows.Core: Main workflow engine and activities
• Elsa.Workflows.Runtime: Workflow execution runtime
• Elsa.Workflows.Api: RESTful API for workflow management
• Elsa.Workflows.Management: Workflow definition management
• Elsa modules: Specialized functionality (HTTP, email, scheduling, etc.)

Build Instructions

Prerequisites

• .NET 9.0 SDK (verified working version: 9.0.305)
• Build time: Initial restore ~1-2 minutes, full compile ~5-10 minutes

Critical Build Information

⚠️ IMPORTANT: The repository has external dependencies that may cause build failures:

1. External NuGet Feeds: Some projects depend on packages from:

   • https://f.feedz.io/elsa-workflows/elsa-3/nuget/index.json (Elsa Studio packages)
   • https://f.feedz.io/sfmskywalker/webhooks-core/nuget/index.json (Webhooks packages)

2. Build Failure Workarounds:

   • Studio apps (Elsa.Studio.Web, ElsaStudioWebAssembly, Elsa.ServerAndStudio.Web) depend on prebuilt studio packages that may not be accessible
   • Server app (Elsa.Server.Web) depends on WebhooksCore package that may not be accessible
   • Core workflow functionality can be built independently
   • Some test projects may fail due to missing external packages

Build Commands

Primary build script: ./build.sh (Linux/macOS) or .\build.cmd (Windows)

# View available targets
./build.sh --help

# Clean build artifacts
./build.sh Clean

# Restore packages (may show warnings for inaccessible feeds)
./build.sh Restore --ignore-failed-sources

# Compile core components (excludes studio apps)
./build.sh Compile

# Run tests (limited due to external dependencies) 
./build.sh Test

# Create NuGet packages
./build.sh Pack

# Full CI pipeline (compile, test, pack)
./build.sh Compile Test Pack

Direct dotnet commands for core components:

# Build specific core projects that don't require external packages
dotnet restore src/modules/Elsa.Workflows.Core/ --ignore-failed-sources
dotnet build src/modules/Elsa.Workflows.Core/ --no-restore
dotnet restore src/modules/Elsa.Workflows.Runtime/ --ignore-failed-sources  
dotnet build src/modules/Elsa.Workflows.Runtime/ --no-restore

# Note: Server apps may fail due to WebhooksCore dependency
# Build and test individual core modules
find test/unit -name "*.csproj" | head -5 | xargs -I {} dotnet build {}

Expected Build Warnings

• NU1900: Unable to load service index for external feeds (safe to ignore)
• NU1801: Service index warnings for feedz.io sources (safe to ignore)
• NU1101: Missing Elsa.Studio packages (blocks studio app builds)

Successful Build Indicators

• Core modules (Elsa.Workflows.Core, etc.) compile successfully
• Server applications (Elsa.Server.Web) build without the studio UI
• Most modules show "succeeded with X warning(s)" (warnings are acceptable)

Testing

Test Structure

• Unit tests: test/unit/ - Fast, isolated tests
• Integration tests: test/integration/ - End-to-end scenarios
• Component tests: test/component/ - Feature testing
• Performance tests: test/performance/ - Benchmarks

Running Tests

# Via NUKE build system
./build.sh Test

# Direct dotnet test (for accessible projects)
dotnet test test/unit/[specific-project]/
dotnet test --no-build --no-restore [project-path]

Note: Many tests may fail to run due to external package dependencies. Focus on core workflow engine tests that don't require studio packages.

Development Guidelines

Code Standards

• Language version: C# latest
• Target framework: .NET 9.0
• Nullable reference types: Enabled
• Implicit usings: Enabled
• EditorConfig: Configured (4-space indentation, CRLF line endings)

Architecture Patterns

• Modular design: Each feature area is a separate project/module
• Dependency injection: Heavy use of Microsoft.Extensions.DependencyInjection
• Activity-based: Workflows are built from composable activities
• Async/await: Extensive use throughout for scalability

Common Gotchas

1. External Dependencies: Studio-related projects require external packages
2. NuGet Source Mapping: Configured in NuGet.Config, restricts where packages can be sourced
3. Multiple Target Frameworks: Some projects conditionally target different frameworks
4. Build Warnings: Many NU1900/NU1801 warnings are expected and safe

Continuous Integration

GitHub Actions Workflow

• Trigger: Pull requests to main branch
• Runner: ubuntu-latest
• .NET Version: 9.x (latest)
• Commands: ./build.cmd Compile Test Pack
• File: .github/workflows/pr.yml (auto-generated by NUKE)

CI Pipeline Steps

1. Checkout code
2. Setup .NET 9.x SDK
3. Execute: Compile → Test → Pack
4. Expected warnings for external feed access
5. Studio apps may be excluded from CI builds

Key Configuration Files

• Build: build/Build.cs (NUKE build configuration)
• Dependencies: Directory.Packages.props (central package management)
• Global settings: Directory.Build.props
• NuGet: NuGet.Config (package sources and mapping)
• Solution: Elsa.sln (119 projects)
• Docker: docker/ directory with multiple Dockerfiles
• GitHub Actions: .github/workflows/ (auto-generated)

Docker Support

Multiple Docker configurations available:

• ElsaServer.Dockerfile - Server only
• ElsaServerAndStudio.Dockerfile - Combined server + studio
• ElsaStudio.Dockerfile - Studio only
• Docker Compose configurations for development

Quick Start for Development

1. Clone and build core components:

   git clone [repo-url]
   cd elsa-core
   ./build.sh Clean Restore --ignore-failed-sources
   

2. Work with core modules (avoid studio dependencies):

   cd src/modules/Elsa.Workflows.Core
   dotnet build
   dotnet test ../../test/unit/[related-tests]/
   

3. Work with core modules that don't require external dependencies:

   cd src/modules/Elsa.Workflows.Core
   dotnet restore --ignore-failed-sources
   dotnet build --no-restore
   

Important Notes for Coding Agents

1. Always use --ignore-failed-sources when restoring packages
2. Focus on core workflow functionality rather than studio UI components
3. Studio apps require external packages that may not be accessible
4. Build warnings are normal - don't try to fix NU1900/NU1801 warnings
5. Test individual modules rather than solution-wide tests when external deps fail
6. Use direct dotnet commands for building specific components when NUKE fails
7. Check project references before attempting builds - some projects have conditional references
8. Start with core modules like Elsa.Workflows.Core, Elsa.Workflows.Runtime which are more likely to build successfully

Trust these instructions for build and development workflows. Only search for additional information if these instructions are incomplete or found to be incorrect.