Fix #1482: method_exists() with string

[Wosi]

Solves phpstan/phpstan#1482

[ondrejmirtes]

This needs a test, preferably inside ImpossibleCheckTypeFunctionCallRuleTest.

[Wosi]

@ondrejmirtes
I added a call to method_exists with a string variable as first parameter in check-type-function-call.php and don't expect to see an error for this line.
Is it OK this way?

[ondrejmirtes]

Yes, the test is fine :)

[ondrejmirtes]

Try (new StringType())->isSuperTypeOf($objectType)->yes() instead. This will also account for unions of constant strings and is generally better.

[Wosi]

If I do this then a call like this method_exists(MethodExists::class, 'undefinedMethod') will no longer produce the error

Call to function method_exists() with 'CheckTypeFunctionCa…' and 'undefinedMethod' will always evaluate to false.

[ondrejmirtes]

Yeah, that's correct. Please write another test for that. See phpstan/phpstan#1267 it's also reported.

[Wosi]

I'm not sure if I got you right. I changed the type check according to your request and removed the expected errors for this call:

method_exists(MethodExists::class, 'undefinedMethod')

[ondrejmirtes]

Thanks!