Fix #9592: Call to an undefined static method after method_exists()

[phpstan-bot]

Summary

When method_exists() was called with a string literal class name (e.g., method_exists('ClassName', 'methodName')), PHPStan did not properly narrow the type for subsequent static method calls on that class. This caused false positive "Call to an undefined static method" errors even though the method's existence was verified.

Changes

• Modified src/Type/Php/MethodExistsTypeSpecifyingExtension.php to also create a ClassConstFetch type narrowing when the first argument is a string literal (not a ClassConstFetch expression like ClassName::class)
• Added rule regression test in tests/PHPStan/Rules/Methods/data/bug-9592.php covering ternary, early return, and if-block patterns
• Added NSRT test in tests/PHPStan/Analyser/nsrt/bug-9592.php verifying the ClassConstFetch expression is narrowed with hasMethod()

Root cause

MethodExistsTypeSpecifyingExtension narrowed the type of the first argument expression ($args[0]->value). When the argument was ClassName::class (a ClassConstFetch node), StaticMethodCallCheck could find the narrowing because it looks up $scope->getType(new ClassConstFetch($class, 'class')) which matches the same expression key.

However, when the argument was a string literal like 'ClassName', the narrowing was stored under the string literal's expression key (e.g., 'ClassName'), not under the ClassConstFetch expression key (e.g., \ClassName::class) that StaticMethodCallCheck looks up. The fix bridges this gap by also creating a narrowing for the equivalent ClassConstFetch expression when a string literal is used.

Test

The regression test covers three patterns:

1. Ternary: method_exists('Class', 'method') ? Class::method() : ''
2. Early return: if (!method_exists('Class', 'method')) { return; } Class::method();
3. If block: if (method_exists('Class', 'method')) { Class::method(); }

All should produce no errors (previously all three produced false positive "undefined static method" errors).

Fixes phpstan/phpstan#9592

[staabm]

feels like the wrong fix