Fantomas tools

Collection of tools used when developing for Fantomas

Prerequisites

To run this tool locally you need:

• Bun
• .NET 8.x SDK

Running locally

• Pull in the source dependencies:

dotnet fsi build.fsx -- -p Fantomas-Git

• Run the Watch pipeline:

dotnet fsi build.fsx -- -p Watch

Making changes to the client should reflect in the tool. The backends are started once; add --server to have them rebuild on changes too:

dotnet fsi build.fsx -- -p Watch --server

Or try the Run pipeline:

dotnet fsi build -- -p Start

This will run a published version of the tools.

• Open http://localhost:9060

Running in Gitpod

• Open the repository via https://gitpod.io/#https://github.com/fsprojects/fantomas-tools

• Run

dotnet fsi build.fsx -- -p Fantomas-Git

dotnet fsi build.fsx -- -p Watch

• Open browser for port 9060

Analyzers

The projects and build.fsx are checked with the Ionide and G-Research analyzers, the pair the Fantomas repository uses:

dotnet fsi build.fsx -- -p Analyze

Every finding is printed, and none of them fails the run: the two packages report below error severity, so the pipeline only fails when a target could not be analyzed at all. Each target also writes a SARIF report to analysisreports/, and those are merged into analysis.sarif in the repository root. CI runs the pipeline on every pull request and uploads that merged report to GitHub code scanning.

AST viewer syntax reader

The AST viewer reads the untyped syntax tree without F# reflection, so it can run under Native AOT. src/server/ASTViewer/SyntaxReader.fs has one function per syntax type that turns a value into a SyntaxNode. Do not edit that file: it is generated from SyntaxTree.fsi and SyntaxTrivia.fsi of the FCS commit the preview Fantomas checkout (FantomasPreviewRepository) builds Fantomas.FCS from.

Run the generator again each time that FCS commit changes:

dotnet fsi build.fsx -- -p Fantomas-Git
dotnet fsi src/server/ASTViewer/GenerateSyntaxReader.fsx

The first command clones or pulls the Fantomas checkouts and builds them, which puts the FCS sources under .deps. The generator then writes and formats SyntaxReader.fs. If the syntax files use a type they do not define, the generator stops and names it. Add a function with that name, starting with a lowercase letter, to the Leaf module in src/server/ASTViewer/SyntaxNode.fs, and run the generator again.

Other pipelines

To see any other avaiable build script pipelines:

dotnet fsi build.fsx -- --help