Find Dead Code

Native Configuration Required

Goal

Detect unused functions, values, types, and modules in your ReScript project using the integrated reanalyze tool, and remove or suppress them.

Steps

1. Enable reanalyze in Settings

Open Settings > Languages & Frameworks > ReScript and enable the Dead Code Analysis option.

The plugin uses reanalyze (bundled with rescript-tools) to perform the analysis. No additional installation is required if you have ReScript in your project.

Note

For ReScript >= 12.1.0, the plugin automatically uses server mode, which keeps the reanalyze process running as a daemon for significantly faster incremental analysis. The server starts automatically when you open a project and restarts if it becomes unresponsive.

2. Open a .res file

Once reanalyze is enabled, open any .res file in your project. The analysis runs as an external annotator — results appear after a short delay.

3. Look for dead code annotations

Unused items are marked with grey text and a warning annotation:

  • Unused values — let bindings that are never referenced

  • Unused types — Type definitions with no usage

  • Unused modules — Modules that are never opened or accessed

  • Redundant optionals — Optional parameters that are always (or never) provided

4. Apply quick fixes

Place the cursor on a dead code warning and press Alt+Enter to see available quick fixes:

  • Remove unused binding — Deletes the unused let declaration

  • Add underscore prefix — Renames the binding with a _ prefix to mark it as intentionally unused (e.g., let _unusedHelper = ...)

Expected Result

Your project is free of unused code, or intentionally unused items are explicitly marked with the _ prefix convention.

Tips

  • Run dead code analysis periodically, especially after refactoring sessions

  • Use the Problems panel (Alt+6) to see all dead code warnings across the project at once

  • The // noinspection comment can suppress specific warnings if needed