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 most common features developers need, and if we're lucky, maybe a few useful new ones!

Requirements

The following must be be installed to run NetPad:

• .NET 6.0 SDK:
  • The environment variable DOTNET_ROOT (or DOTNET_INSTALL_DIR) must be set and point to the directory where .NET is installed.
  • You can have additional .NET SDKs installed but you still need .NET 6 SDK installed too.
• EF Core tools (.NET 6 or higher): (optional) needed to create and use database connections.

Download

You can download the latest version on the Releases page.

Updates

NetPad does not have an auto-update feature yet, but it's in the works. The latest version can be downloaded on the Releases page.

Contribution

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

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
• Add and use database connections (currently only supports Microsoft SQL Server and PostgreSQL). This feature is in early release.
• Auto-save: If 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 with these features:
  • Code completion (Intellisense)
  • CodeLens
  • Semantic highlighting
  • Hover for documentation
  • Format document
  • Go-to implementation
  • Find references
  • Action suggestions
  • Diagnostics

Roadmap 🚧

• Ability to use Console.Read methods to prompt for user input
• Debugger
• Add support for more database providers
• Quality of Life:
  • Support for more complex objects in the results console, ex: Dumping images
  • Exporting results to different file formats, or to the clipboard
  • Change results styling
  • Pop-out results into own window
  • Change max result set length when dumping Entity Framework IQueryable collections (default is 1000 items)
  • Ability to use Console.Read() to ask for input
  • 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

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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
• .NET SDK 5.x: if you plan on running the Electron app. This is not a dependency of NetPad itself but a dependency of the electronize development tool. It, currently, needs this to run.
• 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
electronize start /watch /manifest electron.manifest.dev.js

# OR without watch mode
electronize start /manifest electron.manifest.dev.js /PublishSingleFile false

Note

Only the 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:

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

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