Fix phpstan/phpstan#14455: missing has-offset via conditional type

[phpstan-bot]

Summary

When an early return guard combines empty($arr['key']) with a variable comparison via &&, PHPStan failed to narrow the array type inside a subsequent branch that checked the same variable. For example:

if (empty($aggregation['field']) && $type === 'filter') { return; }
if ($type === 'filter') {
    // $aggregation should be narrowed to hasOffset('field') here
}

PHPStan reported array<string, mixed> instead of non-empty-array<string, mixed>&hasOffset('field').

Changes

• Added processBooleanNotSureSureConditionalTypes() method in src/Analyser/TypeSpecifier.php — a cross-product of the existing processBooleanNotSureConditionalTypes (conditions) and processBooleanSureConditionalTypes (results) methods
• Wired the new method into both the BooleanAnd (falsey context) and BooleanOr (truthy context) conditional expression holder creation

Root cause

The TypeSpecifier creates conditional expression holders to express relationships like "when variable X has type T, then variable Y has type U". These holders are checked when entering branches.

For empty($arr['field']) && $type === 'filter' in the falsey context (after early return):

• The empty() side produces sure types for $arr (intersect with HasOffsetType('field'))
• The $type === 'filter' side produces sure-NOT-types for $type (remove 'filter')

The existing methods only created holders from matching kinds: sure-type conditions with sure-type results (processBooleanSureConditionalTypes), or sure-NOT-type conditions with sure-NOT-type results (processBooleanNotSureConditionalTypes). The cross-product case — sure-NOT-type conditions with sure-type results — was missing. This meant no holder was created to express "when $type is 'filter', then $arr has hasOffset('field')".

Test

Added tests/PHPStan/Analyser/nsrt/bug-14455.php — verifies that after if (empty($aggregation['field']) && $type === 'filter') { return; }, checking if ($type === 'filter') correctly narrows $aggregation to non-empty-array<string, mixed>&hasOffset('field').

Fixes phpstan/phpstan#14455