Update functionMap.php

[PeterSmith8nss]

Apply changes to funcation map for #460

[szepeviktor]

@johnbillion Please comment on this.

[PeterSmith8nss]

Should I have updated the generated file wordpress-stubs.php as well as the source file function-map.php. As the integrations that have failed seem to be a comparison of the output. Peter

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On Tue, 31 Mar 2026 at 15:33, Viktor Szépe ***@***.***> wrote: *szepeviktor* left a comment (php-stubs/wordpress-stubs#461) <#461?email_source=notifications&email_token=A3WI6GODY3FVU7E74R67SLT4TPJKRA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMJWGMYDSNZRGEY2M4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2LK4DSL5RW63LNMVXHIX3POBSW4X3DNRUWG2Y#issuecomment-4163097111> @johnbillion <https://github.com/johnbillion> Please comment on this. — Reply to this email directly, view it on GitHub <#461?email_source=notifications&email_token=A3WI6GODY3FVU7E74R67SLT4TPJKRA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMJWGMYDSNZRGEY2M4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2LK4DSL5RW63LNMVXHIX3POBSW4X3DNRUWG2Y#issuecomment-4163097111>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A3WI6GIUJOL3VQXDKBILYD34TPJKRAVCNFSM6AAAAACXH2V47SVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DCNRTGA4TOMJRGE> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[szepeviktor]

Should I have updated the generated file wordpress-stubs.php as well

No.
Just wait for a few comments.

[johnbillion]

This appears technically correct, but I'm sure there are dozens or hundreds more functions that are impure.

What's the effect of marking them as such?

[szepeviktor]

hundreds more functions that are impure.

I deeply agree with that.

[PeterSmith8nss]

I agree with both of you that more of the WordPress functions are probably impure. These two came up because my code had time-delayed retries of these functions in the event of an error, and PhpStan assumed the value from the first call would be the same for the second (e.g. assumed the second call with the same arguments would always fail too). And that generated a (false) report from PhpStan. I almost wonder whether the default should be to assume WordPress functions are impure unless known not to be.

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On Tue, 31 Mar 2026 at 17:42, Viktor Szépe ***@***.***> wrote: *szepeviktor* left a comment (php-stubs/wordpress-stubs#461) <#461?email_source=notifications&email_token=A3WI6GJHF2YN6HMKUF7N3F34TPYPDA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMJWGM4TONBUGMZKM4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2LK4DSL5RW63LNMVXHIX3POBSW4X3DNRUWG2Y#issuecomment-4163974432> hundreds more functions that are impure. I deeply agree with that. — Reply to this email directly, view it on GitHub <#461?email_source=notifications&email_token=A3WI6GJHF2YN6HMKUF7N3F34TPYPDA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMJWGM4TONBUGMZKM4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2LK4DSL5RW63LNMVXHIX3POBSW4X3DNRUWG2Y#issuecomment-4163974432>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A3WI6GNBC53MTDIBNFEQEX34TPYPDAVCNFSM6AAAAACXH2V47SVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DCNRTHE3TINBTGI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[IanDelMar]

@johnbillion PHPStan, by default, considers functions that return a value to be pure, meaning that it assumes they return the same value for the same input arguments. This behaviour can be disabled in the config by setting rememberPossiblyImpureFunctionValues to false. Adding @phpstan-impure tells PHPStan not to make that assumption, even when rememberPossiblyImpureFunctionValues is true.

We have already added @phpstan-impure to some functions, for example random-value generators. Impurity is about values, not types, so an impure function returning a string will still return a string on every call, but PHPStan will no longer assume that foo() === foo(). See https://phpstan.org/r/fa6bc999-11ae-42ce-b864-c47fd45deddc. Adding @phpstan-impure would, for example, prevent PHPStan from reporting certain ... will always/never evaluate to ... errors and could avoid other issues caused by PHPStan remembering a return value that may in fact change.

Yes, a lot of WordPress functions are impure, probably most of them, because they depend on globals, database queries, filters (though we typically ignore filters anyway), or other external state.

I think that get_transient() and wp_mail() are good candidates for adding @phpstan-impure. The fact that many other WordPress functions are also impure and not marked as such does not seem to me to be an argument against adding it for these two. Hopefully, core will adopt it as well at some point.

@PeterSmith8nss Yes, you should regenerate wordpress-stubs.php. And yes, treating all functions as impure by default and marking pure ones explicitly would be much easier. Ideally, purity or impurity would be declared for all functions. However, that would require someone to review the entire WordPress code base. And that person should first try to have those additional tags added to core directly.

[johnbillion]

I'm happy for this to go in as long as Viktor is.

[szepeviktor]

Okay!
One more thing: Peter, please promise you don't send "impure only" PRs anymore. Thanks!

[PeterSmith8nss]

Have now added generated file.
I promise no more PRs re "impure only"
Personally, I'm adopting "rememberPossiblyImpureFunctionValues: false" as a safer approach. I'd rather have the odd false-positive than miss something because PhpStan wrongly assumed something was Pure.

[szepeviktor]

Thank you, Peter.