FSharp.Refactor for VS Code

Get it from the Visual Studio Marketplace

View -> Command Palette -> FSharp.Refactor to drive the command line tool for the full project:

And IDE light bulbs while you type

150+ functional refactoring hints with one-click quick fixes for F#, delivered through Ionide.

VS Code has no analyzer concept of its own — F# analyzers load through Ionide → FsAutoComplete → FSharp.Analyzers.SDK, from the directories the FSharp.analyzersPath setting names. This extension bundles the FSharp.Refactor analyzer assemblies (both SDK builds: FsAutoComplete loads the one matching its own SDK version and skips the other) and, on first activation, asks to append its analyzers directory to that setting and turn FSharp.enableAnalyzers on. Decline and it stays out of your settings; the FSharp.Refactor: Wire analyzers into Ionide command re-offers it any time, and the Remove command undoes it.

After wiring and a window reload, open any F# file: suggestions appear as Hint-severity squiggles with FR-prefixed codes, each carrying a light-bulb quick fix (Ctrl+.).

The quick fix is titled by what it writes - Fix FR0136 → Guid.NewGuid() beside Fix FR0136 → Guid.Empty - from FsAutoComplete 0.85 on. An older FsAutoComplete titles every fix just Fix FR0136, so a fix and its alternative look the same. Ionide bundles its own FsAutoComplete, which can lag behind (Ionide 7.31 bundles 0.83); when it does, the extension asks once to install or update the fsautocomplete dotnet global tool and point Ionide at it through the global FSharp.fsac.netCoreDllPath setting. Decline and nothing changes; FSharp.Refactor: Use FsAutoComplete 0.85+ re-offers it, and Use Ionide's bundled FsAutoComplete again undoes it. A path it set follows dotnet tool update (which deletes the old version's folder), and is dropped again once Ionide's own FsAutoComplete is as new. A netCoreDllPath you set yourself is never touched.

Six more commands:

• FSharp.Refactor: Status (versions and wiring) — the extension and analyzers versions, whether the analyzers directory is wired into FSharp.analyzersPath (and any stale entry from an older version), Ionide's version, the FsAutoComplete it runs (where, which version, and so whether fix titles say what the fix writes), and whether the fsharp-refactor dotnet tool is installed. The first thing to run when no hints appear.
• FSharp.Refactor: Run the tool on this workspace — the light bulbs fix one finding at a time; this runs the sweep. Picks a solution or project of the workspace, then Report only (--dry-run), Apply fixes, or Apply fixes with --api-changes, in the integrated terminal. Every pass the tool applies is build-verified and rolled back on error, as on the command line; it offers to install the tool when it is missing.
• FSharp.Refactor: Run the tool with --api-changes — the same sweep with the scope gate opened: rules that only fix private or internal declarations by default also rewrite public ones, and cross-file signature changes (FR0090, FR0091) rewrite their call sites project-wide. Asks report-only or apply first.
• FSharp.Refactor: Write a SARIF report for this workspace — a dry run with --report, for code scanning or as the --baseline of a later run. Asks where to write it; .csv and .html paths are written in those formats instead.
• FSharp.Refactor: Create or open the configuration file — writes a fsharprefactor.json of this build's defaults into the workspace root and opens it, or opens the one already there (an existing config holds your decisions and is never replaced). Every rule, plus publicApi, apiChanges, ignorePaths and suppressions, each with a comment. It changes nothing until you edit a line.
• FSharp.Refactor: Review advisory notes as a page — the findings that carry no fix, as a self-contained HTML page opened in your browser. Unlike everything else the tool does, these are only worth anything if a person reads them; the SARIF report is for CI, this is for you. Runs --notes only and writes nothing to your code.

Alternative without this extension: reference the FSharp.Refactor.Analyzers NuGet package and point FSharp.analyzersPath at the restored package — per-project instead of global; see the project README.

Building

pwsh -File CreateVsCodeVsix.ps1
code --install-extension artifacts/fsharp-refactor-<version>.vsix

The version is stamped from the repo's Directory.Build.props, the same single source as the NuGet packages and the Visual Studio extension.

The durable fix

Mutating user settings is a workaround for Ionide having no extension point for third-party analyzer directories. The right long-term shape is an Ionide contributes-style API where an extension declares its analyzer paths and Ionide collects them — worth proposing upstream; this extension then shrinks to a manifest entry.