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b01003f81d
## Summary
This PR includes a behavioral change to how we infer types for public
uses of symbols within a module. Where we would previously use the type
that a use at the end of the scope would see, we now consider all
reachable bindings and union the results:
```py
x = None
def f():
reveal_type(x) # previously `Unknown | Literal[1]`, now `Unknown | None | Literal[1]`
f()
x = 1
f()
```
This helps especially in cases where the the end of the scope is not
reachable:
```py
def outer(x: int):
def inner():
reveal_type(x) # previously `Unknown`, now `int`
raise ValueError
```
This PR also proposes to skip the boundness analysis of public uses.
This is consistent with the "all reachable bindings" strategy, because
the implicit `x = <unbound>` binding is also always reachable, and we
would have to emit "possibly-unresolved" diagnostics for every public
use otherwise. Changing this behavior allows common use-cases like the
following to type check without any errors:
```py
def outer(flag: bool):
if flag:
x = 1
def inner():
print(x) # previously: possibly-unresolved-reference, now: no error
```
closes https://github.com/astral-sh/ty/issues/210
closes https://github.com/astral-sh/ty/issues/607
closes https://github.com/astral-sh/ty/issues/699
## Follow up
It is now possible to resolve the following TODO, but I would like to do
that as a follow-up, because it requires some changes to how we treat
implicit attribute assignments, which could result in ecosystem changes
that I'd like to see separately.
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|---|---|---|
| .. | ||
| annotations | ||
| assignment | ||
| binary | ||
| boolean | ||
| boundness_declaredness | ||
| call | ||
| class | ||
| comparison | ||
| comprehensions | ||
| conditional | ||
| declaration | ||
| diagnostics | ||
| directives | ||
| doc | ||
| exception | ||
| expression | ||
| function | ||
| generics | ||
| ide_support | ||
| import | ||
| literal | ||
| loops | ||
| narrow | ||
| regression | ||
| scopes | ||
| shadowing | ||
| snapshots | ||
| stubs | ||
| subscript | ||
| suppressions | ||
| type_compendium | ||
| type_of | ||
| type_properties | ||
| type_qualifiers | ||
| unary | ||
| with | ||
| .mdformat.toml | ||
| attributes.md | ||
| cycle.md | ||
| dataclass_transform.md | ||
| dataclasses.md | ||
| decorators.md | ||
| del.md | ||
| descriptor_protocol.md | ||
| final.md | ||
| instance_layout_conflict.md | ||
| intersection_types.md | ||
| invalid_syntax.md | ||
| known_constants.md | ||
| mdtest_config.md | ||
| mdtest_custom_typeshed.md | ||
| metaclass.md | ||
| mro.md | ||
| named_tuple.md | ||
| overloads.md | ||
| pep695_type_aliases.md | ||
| properties.md | ||
| protocols.md | ||
| public_types.md | ||
| statically_known_branches.md | ||
| sys_platform.md | ||
| sys_version_info.md | ||
| terminal_statements.md | ||
| type_api.md | ||
| typed_dict.md | ||
| union_types.md | ||
| unpacking.md | ||
| unreachable.md | ||