dotenv: override does not behave correctly with watch enabled

[arkon]

Version

>= 24.12.0

Platform

Darwin MBP-M1-RJQ0.local 24.6.0 Darwin Kernel Version 24.6.0: Wed Nov  5 21:33:58 PST 2025; root:xnu-11417.140.69.705.2~1/RELEASE_ARM64_T6000 arm64

Subsystem

No response

What steps will reproduce the bug?

See https://github.com/arkon/nodejs-env-file-override-repro

When using --watch, subsequent env files do not override the prior ones as expected by the docs if using both --env-file and --env-file-if-exists:

Also, you can pass multiple --env-file arguments. Subsequent files override pre-existing variables defined in previous files.

=== Test 1: --env-file + --env-file-if-exists ===
Without --watch:
v24.11.1 MY_VAR: from_dotenv_local
v24.12.0 MY_VAR: from_dotenv_local
v24.13.0 MY_VAR: from_dotenv_local
v25.3.0 MY_VAR: from_dotenv_local

With --watch:
v24.11.1 MY_VAR: from_dotenv_local
v24.12.0 MY_VAR: from_dotenv       <-- BUG: should be from_dotenv_local
v24.13.0 MY_VAR: from_dotenv       <-- BUG
v25.3.0 MY_VAR: from_dotenv        <-- BUG

=== Test 2: --env-file + --env-file (works correctly) ===
Without --watch:
v24.11.1 MY_VAR: from_dotenv_local
v24.12.0 MY_VAR: from_dotenv_local
v24.13.0 MY_VAR: from_dotenv_local
v25.3.0 MY_VAR: from_dotenv_local

With --watch:
v24.11.1 MY_VAR: from_dotenv_local
v24.12.0 MY_VAR: from_dotenv_local
v24.13.0 MY_VAR: from_dotenv_local
v25.3.0 MY_VAR: from_dotenv_local

=== Test 3: --env-file-if-exists + --env-file-if-exists (works correctly) ===
Without --watch:
v24.11.1 MY_VAR: from_dotenv_local
v24.12.0 MY_VAR: from_dotenv_local
v24.13.0 MY_VAR: from_dotenv_local
v25.3.0 MY_VAR: from_dotenv_local

With --watch:
v24.11.1 MY_VAR: from_dotenv_local
v24.12.0 MY_VAR: from_dotenv_local
v24.13.0 MY_VAR: from_dotenv_local
v25.3.0 MY_VAR: from_dotenv_local

How often does it reproduce? Is there a required condition?

This is always reproducible when using --watch and mixing --env-file and --env-file-if-exists.

What is the expected behavior? Why is that the expected behavior?

Documented override behaviour, aligning with behaviour seen when not using --watch.

What do you see instead?

Subsequent env files do not override earlier ones.

Additional information

No response

[geeksilva97]

I just tested main and 25.0.0 and both seem to work correctly.

[arkon]

I've updated the report and repro to clarify the mix of --env-file and --env-file-if-exists.

[geeksilva97]

I've updated the report and repro to clarify the mix of --env-file and --env-file-if-exists.

Thank you. Will test again.