Dockerfile.dev

# ── Stage 1: deps ────────────────────────────────────────────────────────────
# Install node_modules in an isolated layer so they are only reinstalled when
# package-lock.json changes, not on every source code change.
FROM node:24-slim AS deps

WORKDIR /app

# Copy only the lockfiles — changes to source never invalidate this layer
COPY package.json package-lock.json ./

# ci installs exact versions from the lockfile; --prefer-offline avoids
# redundant registry requests when the layer is cached
RUN --mount=type=cache,target=/root/.npm \
    npm ci --prefer-offline

# ── Stage 2: dev ─────────────────────────────────────────────────────────────
# Runtime image — source is bind-mounted at run time, not baked in.
FROM node:24-slim AS dev

WORKDIR /app

# Copy node_modules from deps stage
COPY --from=deps /app/node_modules ./node_modules

# Copy static config files that don't change often
# (source and public are bind-mounted via docker-compose volumes)
COPY package.json package-lock.json ./
COPY next.config.ts tsconfig.json postcss.config.mjs ./

EXPOSE 3000

# Docker Compose supplies the development command so it can filter noisy watch output.
CMD ["npm", "run", "dev"]