Binary operations on non-empty-string and string should error

[staabm]

closes phpstan/phpstan#6624

[ondrejmirtes]

The right solution here is to introduce Type::isString() and use that. For example your code will continue to fail with literal-string.

[staabm]

The right solution here is to introduce Type::isString() and use that

hmm do you mean adding this method on the Type interface and implement it in all types?
if so, this is a BC break, isn't it?

[ondrejmirtes]

It's not a BC break, implementing custom Type isn't covered by BC promise.

[staabm]

I see. I got the impression because the Type-interface has a @api annotation

[ondrejmirtes]

Otherwise 👍

[ondrejmirtes]

1. || vs. && operator priority needs to be disambiguated with parentheses
2. I don't know why literal-string is mentioned in this condition

[staabm]

1. fixed
2. I mixed up my mental model in "123" would be a literal-string, but it is also a numeric-string, so the additional check is not necessary. fixed a bug so we don't accept literal-string for binary operations

[ondrejmirtes]

1. || vs. && operator priority needs to be disambiguated with parentheses
2. Why isNonEmptyString and not isString?

[staabm]

1. fixed
2. I used non-empty-string because the initial bug report was about non-emptry-string problems, while it already worked for regular string.
   I am now using isString instead of isNonEmptyString in the first block, which renders this second block of changes unnecessary. I removed it.

[ondrejmirtes]

Thank you!