comments in .env files are parsed as values

[MarijnMensinga]

Version

20.12.0+, 21.0.0+, 22.0.0

Platform

Darwin XXX.local 23.4.0 Darwin Kernel Version 23.4.0: Fri Mar 15 00:10:42 PDT 2024; root:xnu-10063.101.17~1/RELEASE_ARM64_T6000 arm64

Subsystem

No response

What steps will reproduce the bug?

# .env

TEST_VAR=OK
# TEST_VAR=WRONG1
#TEST_VAR=WRONG2

# .env.local

#TEST_VAR=WRONG3

# index.js

console.log(process.env.TEST_VAR)

Run with single env file:
nvm run 20.6.0 --env-file=.env index.js => OK
nvm run 20.11.1 --env-file=.env index.js => OK
nvm run 20.12.0 --env-file=.env index.js => WRONG2
nvm run 22.0.0 --env-file=.env index.js => WRONG2

Run with multiple env files:
nvm run 20.11.1 --env-file=.env --env-file=.env.local index.js => OK
nvm run 20.12.0 --env-file=.env --env-file=.env.local index.js => WRONG3
nvm run 22.0.0 --env-file=.env --env-file=.env.local index.js => WRONG3
Note: for simplicity I re-used the .env file, but using different files yields the same behaviour

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

Works as long as --env-file is present

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

I expect only uncomment values in .env files to be parsed as actual values. So the output of the reproduction script should be "OK". This is in-line with every other .env parsing library. Also node v20.6.0 -> v20.11.1 behaves like that:

$ nvm run 20.6.0 --env-file=.env index.js  
Running node v20.6.0 (npm v9.8.1)
OK

$ nvm run 20.11.1 --env-file=.env index.js
Running node v20.11.1 (npm v10.2.4)
OK

$ nvm run 20.11.1 --env-file=.env --env-file=.env.local index.js
Running node v20.11.1 (npm v10.2.4)
OK

What do you see instead?

The last read commented values is outputed instead of the expected value:

$ nvm run 20.12.0 --env-file=.env index.js
Running node v20.12.0 (npm v10.5.0)
WRONG2

$ nvm run 20.12.0 --env-file=.env --env-file=.env.local index.js
Running node v20.12.0 (npm v10.5.0)
WRONG3

$ nvm run 22.0.0 --env-file=.env index.js                      
Running node v22.0.0 (npm v10.5.1)
WRONG2

$ nvm run 22.0.0 --env-file=.env --env-file=.env.local index.js
Running node v22.0.0 (npm v10.5.1)
WRONG3

Additional information

No response

[climba03003]

It is already fixed in #52406
But not yet released.

[MrJithil]

I tested the latest main with the below test case, and seems the issue is not yet fixed with the mentioned PR above.

command
./node --env-file=./.env ./index.js

.env

TEST_VAR=ORIGINAL_VALUE
# TEST_VAR=UNEXPECTED_VALUE
#TEST_VAR=UNEXPECTED_VALUE

index.js
console.log(process.env.TEST_VAR)

output
UNEXPECTED_VALUE

Observation
While using 2 commented lines, the issue is seems exist.

Proposal
Replace the lines starts with comments during parse (Dotenv::ParseContent )

lines = std::regex_replace(lines, std::regex("^\\s*#.*$"), "");

CC: @anonrig @climba03003

[MrJithil]

Please reopen if needed.

[indrodev]

any update when this will be fixed? facing the same issue on current LTS v20.13.1

[climba03003]

cc @IlyasShabi

Double checked with the above repro in comments.
I cannot reproduce the issue. Sorry for the ping.

[targos]

This was fixed in v20.13.0. I verified with the reproduction in the OP. If you have another way to reproduce, please open a new issue.

[indrodev]

.env (example)

#MONGO
MONGO=mongodb://UERNAME:PASSWORD@127.0.0.1:27017/TEST
#MONGO=mongodb://UERNAME:PASSWORD@127.0.0.1:27018/TEST
#MONGO=mongodb+srv://UERNAME:PASSWORD@example.mongodb.net/application

Sorry, I was on node v20.12.2 (even updating to current --lts using nvm)

just fixed the node version issue, the above .env example is working on the current lts (v20.13.1).

Thank you