An in-process Neovim LSP server for Flipper feature flag names. Provides completion, hover, and go-to-definition by reading feature names and descriptions from a YAML config file.

• Neovim 0.11+
• A config/feature-descriptions.yml file in your project root

Using lazy.nvim:

{
  'wassimk/flipper-ls.nvim',
  ft = { 'ruby', 'eruby', 'javascript', 'typescript', 'typescriptreact', 'javascriptreact' },
  config = function()
    vim.lsp.enable('flipper_ls')
  end,
}

Completions trigger when typing flipper method calls such as:

• Features.enabled?("
• Features.feature_enabled?("
• featureEnabled("
• feature_enabled?("
• with_feature("
• without_feature("

The trigger characters are ", ', and : (for Ruby symbols).

When using the featureEnabled JavaScript/TypeScript prefix, feature names are automatically transformed by stripping the ROLLOUT_ prefix and enable_/disable_ prefixes. For example, ROLLOUT_enable_dark_mode becomes dark_mode.

Hover over a feature name to see its description from the YAML file.

Jump to the feature's line in the YAML config file.

The plugin reads feature names from config/feature-descriptions.yml (relative to your project root). This file should contain lines in the format:

ROLLOUT_enable_dark_mode: Allow users to toggle dark mode
ROLLOUT_disable_legacy_ui: Phase out old interface

The LSP server runs entirely in-process within Neovim. No external process is spawned. Feature data is cached in memory after the first request.

The server only activates when it finds config/feature-descriptions.yml under a project root (detected via Gemfile, package.json, or .git).

The defaults work for most projects. For custom paths or prefixes, use vim.lsp.config:

vim.lsp.config('flipper_ls', {
  init_options = {
    features_path = 'config/custom-features.yml',
    prefixes = {
      'Features.enabled?',
      'Features.feature_enabled?',
      'featureEnabled',
      'feature_enabled?',
      'with_feature',
      'without_feature',
    },
  },
})
vim.lsp.enable('flipper_ls')

Run tests and lint:

make test
make lint

Enable the local git hooks (one-time setup):

git config core.hooksPath .githooks

This activates a pre-commit hook that auto-generates doc/flipper-ls.nvim.txt from README.md whenever the README is staged. Requires pandoc.