[ty] Use a more lenient fallback type for failed namedtuple() and NamedTuple calls#22765
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AlexWaygood merged 1 commit intomainfrom Jan 21, 2026
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| let find_keyword = |name: &str| -> Option<&ast::Keyword> { | ||
| keywords | ||
| .iter() | ||
| .find(|kw| kw.arg.as_ref().is_some_and(|arg| arg.id.as_str() == name)) | ||
| }; | ||
| let typename_kw = find_keyword("typename"); | ||
| let field_names_kw = find_keyword("field_names"); | ||
| let typename_kw = call_expr.arguments.find_keyword("typename"); | ||
| let field_names_kw = call_expr.arguments.find_keyword("field_names"); |
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drive-by simplification; no functional change to this bit
Typing conformance resultsNo changes detected ✅ |
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charliermarsh
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Seems reasonable (assuming tests pass and ecosystem changes are clean).
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…NamedTuple` calls
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Summary
This is stacked on top of #22718; review that first.
Currently if a user makes a bad
NamedTuple()call like this:then we emit errors on both calls: one correct error for the bad
NamedTuple()call (it's missing required arguments), and then another spurious error on theBad1()call:The reason for this second, spurious error is that we inferred
type[NamedTupleFallback]for the result of theBad1()call, andNamedTupleFallbackhas this__init__signature, which isn't appropriate in this context -- it actually reflects the arguments you need to pass to theNamedTuplefunction itself in order to create aNamedTupleclass, not the signature of the constructors that allNamedTupleclasses have:ruff/crates/ty_vendored/vendor/typeshed/stdlib/_typeshed/_type_checker_internals.pyi
Lines 63 to 69 in 7e1f07e
This PR updates the fallback type we use when
NamedTupleparsing fails, so that it's more lenient and the spurious error is no longer emitted.Test Plan
mdtests updated