TypeMismatch when Indexing Bytes / String of different lengths

[trocher]

Version Information

• vyper Version (output of vyper --version): 0.4.0
• OS: OSX
• Python Version (output of python --version): 3.11.4

What's your issue about?

When Indexing Bytes or String of different length, depending on the order of the elements in the List it can be that the compiler incorrectly fails to type check.

Most likely related to #4079, #3253

@external
def foo():
    index: uint256 = 1
    a: String[30] = ""
    b: String[257] = ""
    l1: String[257] = [b,a][index] # compiles
    l2: String[257] = [a,b][index] # does not compile

vyper.exceptions.TypeMismatch: Expected String[30][2] but literal can only be cast as DynArray[String[30], 2] or String[30][2].

h/t @ritzdorf

How can it be fixed?

Probably by fixing compare_type for Bytes and Strings.