PHPStan incorrectly thinks variable is 0 after switch when using integer-backed enums #9723
Description
Bug report
In the following two examples, which make use of integer-backed enums, PHPStan seems to be certain that an integer variable has the value 0 after a switch statement, when that's not the case. As a result, it emits a misleading error message when the variable is tested:
- https://phpstan.org/r/199dc290-8894-4b30-aa2d-33eb9ce83456
- https://phpstan.org/r/342eb782-8277-4464-9566-f7dabe71e2dd
In the second example, the error message also suggests that it may be confused about the value of the enumeration constants.
If the enums are removed and replaced by integers, PHPStan correctly reports no errors. Here are the plain integer (no-enum) equivalents of the cases above:
- https://phpstan.org/r/b69e8646-7258-4729-a5b9-270065f2389d
- https://phpstan.org/r/ba586671-5e9d-4d99-b852-b823536bd49e
Code snippet that reproduces the problem
See above
Expected output
For the first two cases with integer-backed enums above, PHPStan should not have reported an error message. It should have behaved exactly like the pure integer non-enum cases.
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