# node 22-alpine, 2026-02-22
FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34

WORKDIR /app

# script/bootstrap installs all prerequisites (make via apk here; node
# and yarn are already in the base image, so those steps are skipped).
# Dependency manifests are copied first so the bootstrap layer is
# cached until they change.
COPY script/ script/
COPY package.json yarn.lock ./
RUN script/bootstrap

COPY . .

# CHECK_EPOCH is a per-invocation nonce supplied by script/cibuild and
# script/docker. Without it an unchanged tree serves this layer from
# cache and the build reports a green it never ran. ARG is stage-scoped,
# so it must be redeclared in every stage that runs checks. The guard
# makes a bare `docker build .` fail loudly instead of silently reusing
# the empty (and therefore stable) cache key. Expand the value into the
# command so the cache miss does not depend on BuildKit's handling of an
# unreferenced ARG.
ARG CHECK_EPOCH
RUN [ -n "$CHECK_EPOCH" ] || exit 1
RUN echo "check epoch: ${CHECK_EPOCH}" && make check