phpstan misses "always false" when using in_array unless strict mode is enabled

[pontus-mp]

Bug report

PHPstan doesn't notice when in_array always returns false, unless strict rules are enabled. This might be related to #2870.

Code snippet that reproduces the problem

https://phpstan.org/r/4129c443-3a90-4dd3-b5e3-2d1d2944eafe

Expected output

9 | Call to function in_array() with arguments 'first'|'second', array('first', 'second') and true will always evaluate to true.

[ondrejmirtes]

This is expected, it's actually "always true" situation.

[ondrejmirtes]

You can turn it on even without strict-rules installed: https://phpstan.org/config-reference#checkalwaystruechecktypefunctioncall

[pontus-mp]

That only seems to have an effect if the third (strict) parameter is true. PHPStan fails to find an issue in this snippet when checkAlwaysTrueCheckTypeFunctionCall is enabled, unless the third parameter is set to true.

https://phpstan.org/r/be7c6ec9-34e0-4d2f-8583-03162b90b7dd

[ondrejmirtes]

Yes, because loose comparison is really complicated and basically any type can equal to any type, given the right value. For example ('0' == false)...

[github-actions]

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