How to install Fantomas in Visual Studio Code?

Install the Fantomas extension from the VS Code marketplace, which integrates the formatter into the editor. Alternatively, use the dotnet tool globally and configure it in your project settings for automated formatting.

Fantomas vs. FSharp.Formatting: which one should I use?

Fantomas is a dedicated code formatter that restructures F# source code for consistency, while FSharp.Formatting focuses on documentation generation and code highlighting. For automated formatting, Fantomas is the better choice; for docs, use FSharp.Formatting.

How to configure Fantomas for custom indentation?

Create a .fantomasrc configuration file or use command-line flags to specify settings like indentation size or spaces vs. tabs. Refer to the official documentation for a full list of options and examples.

Does Fantomas support all F# language features?

Fantomas aims to support latest F# versions, but there can be delays with new language features. Check the GitHub releases or issues for updates on compatibility, especially for cutting-edge syntax.

How to integrate Fantomas into GitHub Actions?

Add a step in your workflow YAML to install the dotnet tool and run fantomas on your codebase. Use conditionals to format only changed files or entire directories, ensuring consistency in CI pipelines.

What if Fantomas breaks my existing code formatting?

Fantomas is opinionated and might reformat code unexpectedly; review the style guide to understand rules. If issues persist, adjust configuration, use version pinning, or report bugs on GitHub with minimal reproductions.

Fantomas — Opinionated F# Code Formatter

What is Fantomas?

Fantomas is an opinionated source code formatter specifically designed for the F# programming language. It automatically reformats F# code to adhere to a consistent style guide, solving the problem of inconsistent formatting across teams and projects.

Target Audience

F# developers and teams working on F# projects who want to enforce a uniform code style and improve codebase maintainability.

Value Proposition

Developers choose Fantomas because it provides a strict, automated formatting solution that eliminates style debates, integrates easily into development workflows, and ensures project-wide consistency without manual intervention.

FSharp source code formatter

Use Cases

Best For

Enforcing consistent code style across F# projects
Automating code formatting in CI/CD pipelines
Eliminating manual formatting debates in F# teams
Improving readability of large F# codebases
Integrating formatting into F# development workflows
Applying opinionated style rules to F# source code

Not Ideal For

Projects with custom, non-standard F# style guides that conflict with Fantomas's defaults
Teams needing real-time, highly configurable in-editor formatting without external tool integration
Codebases where formatting decisions must adapt to specific contexts or legacy F# patterns

Pros & Cons

Pros

Automated Consistency

Fantomas applies a strict, predefined style guide to all F# code, eliminating manual formatting debates and ensuring uniform readability, as highlighted in its opinionated philosophy.

Easy CLI Integration

Available as a dotnet tool with a simple install command, it seamlessly integrates into build pipelines or command-line workflows, per the README example.

Configurable Rules

While opinionated, it offers configuration options to adjust formatting preferences, allowing some customization for project-specific needs, as noted in the key features.

Project-Wide Coverage

Ensures consistent formatting across entire F# projects and teams, improving maintainability of large codebases without manual intervention.

Cons

Opinionated Rigidity

Its strict defaults may not accommodate all custom formatting requirements or niche F# idioms, limiting flexibility for teams with unique style preferences.

Setup Overhead

Integrating Fantomas into CI/CD pipelines or editors requires additional configuration, which can be complex for beginners or in heterogeneous environments beyond basic CLI use.

Version Inconsistencies

Updates might introduce breaking changes in formatting rules, as with any active project, potentially requiring teams to adapt codebases or lock versions.

What is Fantomas?

Target Audience

F# developers and teams working on F# projects who want to enforce a uniform code style and improve codebase maintainability.

Value Proposition

Use Cases

Best For

Enforcing consistent code style across F# projects
Automating code formatting in CI/CD pipelines
Eliminating manual formatting debates in F# teams
Improving readability of large F# codebases
Integrating formatting into F# development workflows
Applying opinionated style rules to F# source code

Not Ideal For

Projects with custom, non-standard F# style guides that conflict with Fantomas's defaults
Teams needing real-time, highly configurable in-editor formatting without external tool integration
Codebases where formatting decisions must adapt to specific contexts or legacy F# patterns

Pros & Cons

Pros

Automated Consistency

Fantomas applies a strict, predefined style guide to all F# code, eliminating manual formatting debates and ensuring uniform readability, as highlighted in its opinionated philosophy.

Easy CLI Integration

Available as a dotnet tool with a simple install command, it seamlessly integrates into build pipelines or command-line workflows, per the README example.

Configurable Rules

While opinionated, it offers configuration options to adjust formatting preferences, allowing some customization for project-specific needs, as noted in the key features.

Project-Wide Coverage

Ensures consistent formatting across entire F# projects and teams, improving maintainability of large codebases without manual intervention.

Cons

Opinionated Rigidity

Its strict defaults may not accommodate all custom formatting requirements or niche F# idioms, limiting flexibility for teams with unique style preferences.

Setup Overhead

Integrating Fantomas into CI/CD pipelines or editors requires additional configuration, which can be complex for beginners or in heterogeneous environments beyond basic CLI use.

Version Inconsistencies

Updates might introduce breaking changes in formatting rules, as with any active project, potentially requiring teams to adapt codebases or lock versions.

Fantomas

What is Fantomas?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Found a gem we're missing?

Fantomas

What is Fantomas?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Found a gem we're missing?