Format code with fourmolu

hs

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# Thin wrapper to run Haskell tooling (stack, hpack, fourmolu, hlint, ...)
+# inside a Docker image with our system dependencies pre-installed.
+# Usage: ./hs <cmd> [args]
+set -euo pipefail
+
+PROJECT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+# Build a custom image on top of flipstone/haskell-tools that includes
+# the C libraries our Haskell packages need (e.g. libsqlite3-dev).
+IMAGE="orville-sqlite-haskell-tools"
+
+docker build \
+  --quiet \
+  -t "${IMAGE}" \
+  -f - \
+  "${PROJECT_DIR}" << DOCKERFILE
+FROM ghcr.io/flipstone/haskell-tools:debian-ghc-9.10.3-5d6640d
+RUN apt-get update -qq && apt-get install -y -qq libsqlite3-dev
+DOCKERFILE
+
+# Named Docker volume shared across all worktrees so cached
+# GHC/dependencies don't need rebuilding per worktree.
+STACK_ROOT_VOLUME="orville-sqlite-stack-root"
+
+docker volume inspect "${STACK_ROOT_VOLUME}" > /dev/null 2>&1 || \
+  docker volume create "${STACK_ROOT_VOLUME}" > /dev/null
+
+exec docker run --rm -i $([ -t 0 ] && printf -- -t) \
+  -v "${PROJECT_DIR}:/work" \
+  -v "${STACK_ROOT_VOLUME}:/stack-root" \
+  -e STACK_ROOT=/stack-root \
+  -w /work/orville-sqlite \
+  "${IMAGE}" \
+  "$@"