FROM node:18.2.0-alpine3.15 as base
RUN apk update && apk add git

RUN npm i -g turbo

FROM base as pruner

# +++ The "installer" layer COPYs from "pruner" using absolute path "/app/...", so presumably we 
# need to set that as the WORKDIR here when we copy those files into the pruner layer
WORKDIR /app 

# (...Was the intent to have the .git artifacts in a directory above /app?)

COPY .git ./.git
COPY . .

# +++ adding --docker to "turbo prune", since the next layer copies
# from ../out/json. If I'm understanding the docs correctly,
# ../json is only generated if the --docker flag is present
RUN turbo prune --scope=frontend --docker

# +++ Derive FROM "base" layer and COPY files from "pruner" layer.
# Since the full source is copied into the pruner layer in the above block (COPY . .), 
# doing "FROM pruner..." for the installer layer would mean a rebuild 
# (and re-run of yarn install) on any file change....I think
FROM base AS installer

# +++ COPY commands below are using a mix of absolute a relative paths, so we need to set WORKDIR here
WORKDIR /app

# +++ trailing slashes on dest affect COPY behavior, not needed on source paths
COPY --from=pruner /app/out/json .
COPY --from=pruner /app/out/yarn.lock ./yarn.lock

# +++  buildkit caching of yarn install command
RUN --mount=type=cache, sharing=locked, target=/usr/local/share/.cache/yarn/v6, id=yarncache yarn install

FROM installer as builder
WORKDIR /app

# +++ Changed "COPY --from=pruner .git ./.git" to "COPY --from=pruner /app/.git ./.git", 
# given the changes to "pruner" layer above. Again, feels like I might be missing 
# something regarding the intended location for the .git artifacts
COPY --from=pruner /app/.git ./.git

# +++ Copying the root dir of 'installer' to root dir of 'builder' is redundant since the builder is already derived FROM installer, I think?
# COPY --from=installer /app .

# +++ Was "COPY --from=builder", which throws an error (circular). Assuming it was meant to copy from "pruner"
COPY --from=pruner /app/out/full .

# +++ Use "filter" argument instead of scope and include dependencies.
RUN turbo run build --filter=frontend...

# Start the app
FROM builder as runner
EXPOSE 3000

# +++ Unless there's some reason I'm unaware of, I feel like this should be CMD instead of RUN,
# since "yarn start" probably isn't adding anything to the "runner" layer that we'd want to commit...right?
CMD ["yarn", "--cwd", "packages/frontend", "start"]

## BASE ##
FROM node:18.2.0-alpine3.15 as base
RUN apk update && apk add git
RUN npm i -g turbo

## PRUNER ##
FROM base as pruner
WORKDIR /app 

COPY .git ./.git
COPY . .

RUN turbo prune --scope=frontend --docker

## INSTALLER ##
FROM base AS installer
WORKDIR /app

COPY --from=pruner /app/out/json .
COPY --from=pruner /app/out/yarn.lock ./yarn.lock

RUN --mount=type=cache, sharing=locked, target=/usr/local/share/.cache/yarn/v6, id=yarncache yarn install

## BUILDER ##
FROM installer as builder
WORKDIR /app

COPY --from=pruner /app/.git ./.git
COPY --from=pruner /app/out/full .

RUN turbo run build --filter=frontend...

## RUNNER ##
FROM builder as runner
EXPOSE 3000

CMD ["yarn", "--cwd", "packages/frontend", "start"]