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Setting undefined to process.env.* sets a "undefined" string value #48875
Description
Activity
Documented behavior and not subject to change; process.env is special and kind of magical.
Use
delete process.env.whateverto unset properties.I accept it being magical, and find the automatic casting to strings somewhat a smart trick, but setting
undefinedand being set to anundefinedstring, I find it more like a bug... For other values includingnullis fine for me, but forundefined, what are the reasons behind that behaviour?Ok, current behaviour is properly documented at https://nodejs.org/api/process.html#processenv, but as deprecated. Can we left this issue open for when the current implicit conversion to string gets removed, so in addition of allowing only
string,number, orbooleanvalues (although I would be more strict and left just onlystrings), can be also acceptedundefinedas a way to remove the entry?That "may result in a thrown error" is a bit of a paper tiger, it was already weakened from "will" to "may" (ref) and I don't expect it to ever happen, it would simply break too much of the ecosystem for no good reason.
can be also accepted undefined as a way to remove the entry?
That was proposed back in 2018 and was shot down for backwards compatibility reasons: #18158
The threshold for breaking changes is really, really high. And it should be.
@bnoordhuis, I've read the links you posted, it's sad the decision that was taken, specially by maintaining a broken API for backwards compatibility instead of fixing it :-( But I suppose I would need to deal with it... Luckily it doesn't have a direct impact on me, just found that on mid development and did a proper fix on my code, so this doesn't affect me, but anyway I thoung should notify it.
Version
v20.4.0
Platform
Linux executive 6.2.0-25-generic #25-Ubuntu SMP PREEMPT_DYNAMIC Fri Jun 16 17:05:07 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
Subsystem
process.env
What steps will reproduce the bug?
Assign
undefinedto any value onprocess.env, for exampleprocess.env.foo = undefined.How often does it reproduce? Is there a required condition?
Always.
What is the expected behavior? Why is that the expected behavior?
Since values assigned to entries in
process.envare always casted tostringand it's not possible to have any of them set to theundefinedvalue, then it should be fully removed from theprocess.envobject, allowing this way to get the entry unset.What do you see instead?
I get the entry assigned the string
undefinedas value.Additional information
The same happens with
null, that gets assigned with thenullstring, so it's not possible to differenciate when setting it tonullor the string"null". In this case I'm not sure of what should be the correct behaviour, since it's similar to what happens in SQL... Maybe setting the environment variable to an empty string?For reference, assigning an object gets serialized as
[object Object], that sort of makes sense,