NetPad

A cross-platform C# editor and playground.

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Motivation

We love LINQPad, but we also miss its tremendous utility when not working on Windows. This is an effort to develop an open-source, web-enabled, cross-platform alternative.

The goal isn't to reach 100% feature parity with LinqPad, but to offer an acceptable alternative that covers the features developers most commonly need, and if we're lucky, a few new useful ones!

If you like the project, please star it 🌟!

Requirements

The following must be be installed to use NetPad:

• .NET SDK (v6 or v7)
• EF Core tools (.NET 5 or higher): (optional) needed to create and use database connections.

Download

Download the latest version or an older version from the Releases page.

Note: NetPad is not a signed application. On macOS when you run NetPad the first time you will prompted with a message saying the app is damaged and can't be opened. To resolve this run this in a terminal:

sudo xattr -cr /path/to/NetPad.app

Updates

NetPad checks for updates on startup and will let you know when a new version is available. While it cannot yet install the latest update automatically, that feature is in the works!

The latest version can be downloaded from the Releases page.

Contribution

This is a work in progress and still in preview. All contributions are welcome!

If you like NetPad, please consider sponsoring it with a cup of coffee ($5) a month, every bit helps me maintain this project and deliver more features. Thank you ❤️

Join our new Discord server to collaborate with the community.

Features 🚀

• The basics:
  • Write, save and run your own scripts
  • Manage namespaces
  • Standard code editor features powered by Monaco editor
• Dump complex objects to the results console and export results to Excel or HTML
• Choose the .NET SDK version you want to use per script
• Add and use database connections (supports Microsoft SQL Server and PostgreSQL, more coming soon!)
• Run SQL queries
• Auto-save: When you close NetPad, it will auto-save your changes and restore them the next time you fire it up
• Add NuGet packages
• Reference assemblies from disk
• Monaco Editor & OmniSharp offer an editor experience similar to Visual Studio Code:
  • Code completion (Intellisense)
  • Semantic highlighting
  • CodeLens
  • Inlay hits
  • Hover for documentation
  • Format document
  • Go-to implementation
  • Find references
  • Action suggestions
  • Diagnostics
  • Document highlighting

Roadmap 🚧

• Debugging
• Support for more database providers
• Hyperlink driven Lazy-loading of results, and a DataGrid view
• Benchmark your code
• Referencing other scripts
• View your code's Syntax Tree
• View your code as IL
• Export a script as a "ready to run" .NET app
• Export a script as a C# project
• Ability to run a script from the command-line
• Git tracking of script changes
• More advanced Dump() capabilities:
  • Dump HTML controls and interact with them
  • Dump images, SVGs, and bitmaps
  • Dump code with syntax highlighting
• Quality of Life:
  • User-defined results styling
  • Workspaces/Sessions
• More OmniSharp integrations:
  • Code fix suggestions
  • Format selection
  • Format as you type
  • Go-to definition
  • Go-to symbol
  • Rename symbol
  • ...and more
• Plugins & Theming

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Tech Stack 💻

• .NET Core
• Electron.NET (github)
• Aurelia 2 (docs)

How it works: In a nutshell

NetPad runs an ASP.NET web app that hosts a web-based user interface. It can be packaged as an Electron desktop app or served and accessed on any browser.

Communication between the user interface and the ASP.NET backend occurs via HTTP calls and SignalR.

Development

This section describes how to build and run NetPad from source. NetPad can be run as an Electron desktop app or as a web application accessed with a web browser.

Requirements

• Node v16+ (npm v8+)
• .NET SDK 6.x
• EF Core tools 6.x (or higher)

NetPad as an Electron desktop app

1. Run the SPA

# Install dependencies
cd Apps/NetPad.Apps.App/App
npm install

# Start the development web server
npm start

2. Run the .NET app

Install the Electron.NET CLI tool:

dotnet tool install ElectronNET.CLI -g

Start the app:

cd Apps/NetPad.Apps.App

# Start in watch mode (remove '/watch' to run without watch mode)
electronize start /watch /manifest electron.manifest.dev.js

# For macOS ARM, append the following to the 'electronize start' command
/target custom "osx-arm64;mac" /electron-arch arm64

Note

Only the very first electronize start is slow. Later runs are much faster.

NetPad as a Web app (accessed from a browser)

1. Run the SPA

# Install dependencies
cd Apps/NetPad.Apps.App/App
npm install

# Start the development web server
npm run start-web

2. Run the .NET app

cd Apps/NetPad.Apps.App
dotnet watch run --environment Development

and access the app via your web browser, ex: http://localhost:57930

Packaging 📦

The Electron app is built and packaged using electron-builder. Configuration is in the electron.manifest.js file.

Build the app for the desired platform from the root directory of the NetPad.Apps.App project:

# For x64:
electronize build /target win /manifest electron.manifest.js /PublishSingleFile false
electronize build /target osx /manifest electron.manifest.js /PublishSingleFile false
electronize build /target linux /manifest electron.manifest.js /PublishSingleFile false

# For macOS ARM:
electronize build /target custom "osx-arm64;mac" /electron-arch arm64 /manifest electron.manifest.js /PublishSingleFile false

Packaged files can be found in the bin/Desktop folder.

Note

Alternatively, on Linux, the /scripts/package-electron.sh script can be used to package the Electron app, in which case packaged files can be found in the /dist/ folder.

See the Electron.NET docs for additional CLI options when packaging the app, and electron-builder for additional configuration options.

Resources 📚:

• Docs: Go
• More on SPA app startup and running tests: Go