Using --env with --mount ignores filename

[saibotsivad]

I created a repo with the minimum setup to reproduce.

---

When using --mount in sub-directories and --env the filename passed in is ignored.

Working

If the filename is the default .env

miniflare --env ./route-b/.env \
  --mount a=./route-a \
  --mount b=./route-b \
  --watch \
  --debug \
  -p 3000

The variables in route-b/.env are correctly bound.

Not Working

If the filename is not the default .env.test

miniflare --env ./route-a/.env.test \
  --mount a=./route-a \
  --mount b=./route-b \
  --watch \
  --debug \
  -p 3000

What I expect

The variables in route-a/.env.test should be bound.

What actually happens

The variables are not bound, and I get this error:

ReferenceError: MY_KEY_A is not defined
    at /path/to/repro-miniflare-issue-001/route-a/worker/index.js:4:3
    at /path/to/repro-miniflare-issue-001/node_modules/@miniflare/shared/src/event.ts:29:9
    at EventTarget.<anonymous> (/path/to/repro-miniflare-issue-001/node_modules/@miniflare/shared/src/event.ts:77:9)
    at EventTarget.[nodejs.internal.kHybridDispatch] (node:internal/event_target:562:20)
    at EventTarget.dispatchEvent (node:internal/event_target:504:26)
    at EventTarget.dispatchEvent (/path/to/repro-miniflare-issue-001/node_modules/@miniflare/shared/src/event.ts:63:18)
    at EventTarget.dispatchEvent (/path/to/repro-miniflare-issue-001/node_modules/@miniflare/shared/src/event.ts:87:26)
    at EventTarget.[kDispatchFetch] (/path/to/repro-miniflare-issue-001/node_modules/@miniflare/core/src/standards/event.ts:356:13)
    at EventTarget.[kDispatchFetch] (/path/to/repro-miniflare-issue-001/node_modules/@miniflare/core/src/index.ts:1067:31)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)

[mrbbot]

Hey! 👋 --env only applies to the parent worker. All mounted worker configuration must be derivable from package.json, .env and wrangler.toml files inside the mounted directory. No configuration from the parent worker (aside from the watch and storage persistence options) is copied to mounted workers. This is an intentional design decision, allowing each mounted worker to have its own separate bindings. You can set a custom --wrangler-env for each mount using an @:

miniflare --mount a=./route-a@test

# ./route-a/wrangler.toml
# ...
[env.test.vars]
KEY = "value"

[saibotsivad]

Would you be open to a pull request describing that a bit more in the docs?

[mrbbot]

Of course! 🙂

[mrbbot]

Hey! 👋 We haven't heard from you for a while, so I'm going to close this issue. It's unlikely we'll have time to fix this in Miniflare 2. Our development effort is primarily focused on version 3. Miniflare 3 no longer uses mounts, instead preferring an array of workers. 👍