Improve return type of range() function to always yield a non-empty-list

[FeBe95]

Description

By definition, the range() function will never return an empty array. This PR updates the RangeFunctionReturnTypeExtension to follow this definition for all cases.

Note

PHP 8.3 changed how certain “special” or unusual range() calls are handled, but this does not affect the aforementioned definition.

Example:

range(1, 5, -1); // increasing range with a negative step

Up to PHP 8.2, the interpreter attempted to infer a sensible result (e.g. by normalizing the step). Starting with PHP 8.3, such calls either emit warnings or throw errors instead.

Example

range(1, $someInteger);

• Before:

  list<int>

• Now:

  non-empty-list<int>

Implementation

Some return types previously did not use NonEmptyArrayType. This PR applies NonEmptyArrayType to all possible return types of range(), ensuring they differ only in their inner element type.

To avoid duplication, a small helper method getNonEmptyListOfType($type) was introduced and reused across the 9 different return statements.