[ty] Model int and str enum value normalization

[charliermarsh]

Summary

For enums that inherit from int or str, Python converts each assigned value before storing it.

For example:

class Number(int, Enum):
    FALSE = False
    ZERO = 0

Python converts False to 0. Therefore:

• Number.FALSE.value is 0, not False.
• Number.ZERO is another name for Number.FALSE, not a separate member.

Previously, we reasoned from the values as written (False and 0) and could incorrectly treat them as different members. We now account for the conversion performed by int or str. And when we can't reliably predict it, we return a less precise type.

[astral-sh-bot]

Typing conformance results

No changes detected ✅

Current numbers

The percentage of diagnostics emitted that were expected errors held steady at 94.47%. The percentage of expected errors that received a diagnostic held steady at 89.19%. The number of fully passing files held steady at 95/134.

[astral-sh-bot]

Memory usage report

Memory usage unchanged ✅

[astral-sh-bot]

ecosystem-analyzer results

Lint rule	Added	Removed	Changed
invalid-argument-type	0	7	0
Total	0	7	0

Raw diff:

schemathesis (https://github.com/schemathesis/schemathesis)
- src/schemathesis/generation/overrides.py:75:59 error[invalid-argument-type] Argument to function `lookup_parameter` is incorrect: Expected `str`, found `Literal["query", "header", "path", "cookie", "body"] | None`
- src/schemathesis/generation/dictionaries.py:112:73 error[invalid-argument-type] Argument to function `_find_parameter_binding` is incorrect: Expected `str`, found `Literal["query", "header", "path", "cookie", "body"] | None`
- src/schemathesis/generation/dictionaries.py:115:97 error[invalid-argument-type] Argument to function `_find_parameter_binding` is incorrect: Expected `str`, found `Literal["query", "header", "path", "cookie", "body"] | None`
- src/schemathesis/generation/dictionaries.py:230:21 error[invalid-argument-type] Argument is incorrect: Expected `str`, found `Literal["query", "header", "path", "cookie", "body"] | None`
- src/schemathesis/specs/openapi/extra_data_source.py:181:9 error[invalid-argument-type] Argument is incorrect: Expected `str`, found `Literal["query", "header", "path", "cookie", "body"] | None`
- src/schemathesis/specs/openapi/extra_data_source.py:199:9 error[invalid-argument-type] Argument is incorrect: Expected `str`, found `Literal["query", "header", "path", "cookie", "body"] | None`
- src/schemathesis/specs/openapi/extra_data_source.py:645:38 error[invalid-argument-type] Argument to bound method `list.append` is incorrect: Expected `tuple[str, str]`, found `tuple[Literal["query", "header", "path", "cookie", "body"] | None, str]`

Full report with detailed diff (timing results)

[codspeed-hq]

Merging this PR will not alter performance

✅ 87 untouched benchmarks
⏩ 64 skipped benchmarks¹

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_{Comparing charlie/normalize-built-in-enum-mixin-values (b271885) with main (df383e1)}

Footnotes

1. 64 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩