Building a Vite plugin for F# by Florian Verdonck

May 8, 2024

In the Building a Vite plugin for F# presentation, Florian Verdonck explores the development of an F# application using Vite, a development server, and Fable, a compiler for transforming F# code to JavaScript. Florian discusses the challenges of connecting F# to Vite and the benefits of using Fable for hot module reloading. He also shares his reservations about the recommended way of using Fable within Vite and introduces the concept of creating a Fable plugin for Vite to improve the development experience. Throughout the video, Florian demonstrates the process of creating the plugin, detecting an F# project, and handling file changes. He also discusses the challenges he encountered during development, including debugging issues within the .NET process and maintaining the project with new versions of Vite, Fable, and .NET. Florian encourages adoption of the project and invites viewers to contribute to the FP ecosystem through the Amplifying FP initiative.

Building Functional Web Apps with F#: A comprehensive overview

Florian introduces F# as a functional programming language for the .NET runtime, likening it to OCaml or F# for .NET. He then explores Fable, a compiler that transforms F# source code into JavaScript, and Vite, a development server known for its instant feedback feature, setting the stage for building a Vite plugin for F#.


Creating a seamless development experience

Florian’s journey begins with a demonstration of setting up a Vite project, installing dependencies, and running the server. He identifies the need for smoother integration between Fable and Vite, paving the way for the creation of a plugin to bridge the gap and enhance the developer workflow.


Harnessing Fable for real-time refresh

The presentation dives deeper into leveraging Fable to achieve hot module reload functionality akin to React’s experience in an F# project. Florian showcases the process of scaffolding files, compiling code, and ensuring seamless interaction between F# and JavaScript components.


Tackling integration challenges

As Florian progresses, he confronts challenges associated with integrating Fable within the Vite environment, highlighting concerns such as file reading inefficiencies and the need for improved configuration. He introduces the concept of creating a Fable plugin for Vite to streamline the development process further.


Building a Vite plugin for F#

The pivotal moment arrives as Florian unveils the development of the Vite plugin for F#, enabling direct transformation of F# source code into JavaScript within the Vite ecosystem. He navigates through the intricacies of plugin creation, from configuring transformation processes to handling React components for fast refresh capabilities.


Overcoming development hurdles

Throughout the presentation, Florian candidly shares the hurdles he faced, from managing file changes to debugging issues within the .NET process. He emphasizes the importance of collaboration and highlights the need for sustainable development practices to foster community adoption.


Looking towards the future

Despite the challenges, Florian remains optimistic about the future of F# development, advocating for increased developer participation and funding initiatives. He encourages contributions to open-source projects and invites attendees to join the discourse on improving the F# ecosystem.



Florian Verdonck’s presentation on building a Vite plugin for F# offers a comprehensive insight into the intersection of functional programming, web development, and tooling integration. As the F# community continues to evolve, Florian’s contributions pave the way for a more seamless and efficient developer experience, fostering innovation and growth in the realm of functional web app development.


Additional resources

Check out more from the MeetUp Func Prog Sweden. Func Prog Sweden is the community for anyone interested in functional programming. At the MeetUps the community explore different functional languages like Erlang, Elixir, Haskell, Scala, Clojure, OCaml, F# and more.