[Dotenv] Should we document that order of environment variables within the dotenv file matters?

[emodric]

Hi.

Recently I've ran into an issue where I didn't realize that order of environment variables within a dotenv file matters. For example, having two files, .env and .env.local with:

.env

A=C
B=D

.env.local

TESTVAR=$A-$B
A=E
B=F

results in TESTVAR resolving to C-D, basically taking the variables from .env file as they are defined before the TESTVAR itself. However, when moving the TESTVAR variable to the bottom of the file:

A=E
B=F
TESTVAR=$A-$B

makes the TESTVAR variable resolve to E-F, because now the new values are defined earlier.

Should something like this be documented?

Thanks!

[xabbuh]

That's consistent with how shells parse these files, right? Then maybe just a small sentence could be enough.

[emodric]

I figured that out a bit later after I posted this, yes. There are probably more devs out there who are not aware of it, so any kind of mention in the docs might be good.