Fix phpstan/phpstan#3128: array ignored in @param array|stdClass[] $foo

[phpstan-bot]

Summary

When writing @param array|stdClass[] $foo, PHPStan incorrectly parsed this as array<stdClass> instead of array|array<stdClass>. This caused false positives when passing a plain array (e.g., [1]) to such a parameter, since array should accept any array.

Changes

• Modified TypeNodeResolver::resolveUnionTypeNode() in src/PhpDoc/TypeNodeResolver.php to use a two-pass approach for merging [] shorthand types with other iterables
• Pass 1 handles non-array iterables (ObjectType like Collection, IterableType) — these get their value type annotated by the [] notation as before
• Pass 2 only merges ArrayType/ConstantArrayType if at least one non-array iterable was merged in Pass 1, preserving patterns like Foo[]|Collection|array → array<Foo>|(Collection & iterable<Foo>)
• Updated expected errors in tests/PHPStan/Rules/Functions/MissingFunctionParameterTypehintRuleTest.php for array|int[] now correctly resolving to array
• Added regression test in tests/PHPStan/Rules/Methods/data/bug-3128.php

Root cause

TypeNodeResolver::resolveUnionTypeNode() had a single-pass loop that merged Foo[] value types into all iterable types in the union, including plain array. When array (with MixedType value type) was in a union with stdClass[], the merge replaced array with array<stdClass>, incorrectly narrowing the type. The fix introduces a two-pass approach: first merge with non-array iterables, then only merge with array types if a non-array merge occurred — indicating the [] notation is annotating a collection pattern rather than being a standalone array type.

Test

Added tests/PHPStan/Rules/Methods/data/bug-3128.php testing both @param array|stdClass[] $foo and @param stdClass[]|array $bar with a plain array argument [1]. Both should produce no errors at level 5.

Fixes phpstan/phpstan#3128