Summary

I just fixed a longstanding bug in pyright that ty appears to suffer from too. It's related to literal patterns in case statements. The runtime uses equality checks for literal pattern matching, but equality checks can succeed for non-overlapping types.

Consider the following:

def func(x: int):
    match x:
        case 1.0:
            reveal_type(x) # ty incorrectly reveals Never here
            print("This code is reachable")

func(1)

Version

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