#!/bin/sh
# script/lint: run the linter. The linter is never installed on the host
# and never invoked there — it runs in a container, one way, everywhere,
# so a run cannot inherit another checkout's cache, another process's
# lock, or a host toolchain that differs from the pinned one. Linting
# happens as a build step (see Dockerfile.lint), so a successful build
# is a clean lint, and it works where the docker daemon is remote and
# bind mounts are impossible.
set -eu

ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"

main() {
    cd "$ROOT"
    # Assign on its own line: a failing command substitution inside an
    # argument does not trip `set -e`, which would silently degrade the
    # nonce to an empty constant. `$$` is required because busybox `date`
    # drops %N without erroring. Without a fresh nonce the lint layer is
    # served from cache and this script exits 0 having linted nothing.
    epoch="$(date +%s%N)$$"
    docker build \
        --build-arg CHECK_EPOCH="$epoch" \
        -f Dockerfile.lint \
        .
}

main "$@"