HA
Fourmolu + HLint
Fourmolu for deterministic Haskell formatting and HLint for style and correctness linting
Details
Language / Topic
HaskellCategory
Linter / Formatter
Rules
balanced
- Configure `fourmolu` via `fourmolu.yaml` — set `indentation`, `comma-style`, and `import-export-style` for consistent formatting across contributors.
- Run `hlint src/` in CI and fail on any hints — use `{-# ANN module "HLint: ignore" #-}` sparingly only for deliberate deviations.
- Use `fourmolu --mode check` in CI to verify formatting without modifying files.
- Pin `fourmolu` version in `cabal.project` or `stack.yaml` extra-deps to guarantee identical formatting output across development machines.
- Suppress specific `hlint` hints with inline `{- hlint ignore "Redundant bracket" -}` comments rather than disabling entire modules.
- Enable `-Weverything` in GHC options and selectively disable only irrelevant warnings — treat warnings as errors with `-Werror` in CI builds.
- Use `stan` (Haskell Static Analyser) alongside HLint for deeper checks on runtime safety and anti-pattern detection.