## Summary
This changeset adds support for precise type-inference and
boundness-handling of definitions inside control-flow branches with
statically-known conditions, i.e. test-expressions whose truthiness we
can unambiguously infer as *always false* or *always true*.
This branch also includes:
- `sys.platform` support
- statically-known branches handling for Boolean expressions and while
loops
- new `target-version` requirements in some Markdown tests which were
now required due to the understanding of `sys.version_info` branches.
closes#12700closes#15034
## Performance
### `tomllib`, -7%, needs to resolve one additional module (sys)
| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|:---|---:|---:|---:|---:|
| `./red_knot_main --project /home/shark/tomllib` | 22.2 ± 1.3 | 19.1 |
25.6 | 1.00 |
| `./red_knot_feature --project /home/shark/tomllib` | 23.8 ± 1.6 | 20.8
| 28.6 | 1.07 ± 0.09 |
### `black`, -6%
| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|:---|---:|---:|---:|---:|
| `./red_knot_main --project /home/shark/black` | 129.3 ± 5.1 | 119.0 |
137.8 | 1.00 |
| `./red_knot_feature --project /home/shark/black` | 136.5 ± 6.8 | 123.8
| 147.5 | 1.06 ± 0.07 |
## Test Plan
- New Markdown tests for the main feature in
`statically-known-branches.md`
- New Markdown tests for `sys.platform`
- Adapted tests for `EllipsisType`, `Never`, etc
Fix#14558
## Summary
- Add `typing.NoReturn` and `typing.Never` to known instances and infer
them as `Type::Never`
- Add `is_assignable_to` cases for `Type::Never`
I skipped emitting diagnostic for when a function is annotated as
`NoReturn` but it actually returns.
## Test Plan
Added tests from
https://github.com/python/typing/blob/main/conformance/tests/specialtypes_never.py
except from generics and checking if the return value of the function
and the annotations match.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
Closes#14588
```py
x: Literal[42, "hello"] = 42 if bool_instance() else "hello"
reveal_type(x) # revealed: Literal[42] | Literal["hello"]
_ = ... if isinstance(x, str) else ...
# The `isinstance` test incorrectly narrows the type of `x`.
# As a result, `x` is revealed as Literal["hello"], but it should remain Literal[42, "hello"].
reveal_type(x) # revealed: Literal["hello"]
```
## Test Plan
mdtest included!
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
- Emit diagnostics when looking up (possibly) unbound attributes
- More explicit test assertions for unbound symbols
- Review remaining call sites of `Symbol::ignore_possibly_unbound`. Most
of them are something like `builtins_symbol(self.db,
"Ellipsis").ignore_possibly_unbound().unwrap_or(Type::Unknown)` which
look okay to me, unless we want to emit additional diagnostics. There is
one additional case in enum literal handling, which has a TODO comment
anyway.
part of #14022
## Test Plan
New MD tests for (possibly) unbound attributes.
Minor cleanup and consistent formatting of the Markdown-based tests.
- Removed lots of unnecessary `a`, `b`, `c`, … variables.
- Moved test assertions (`# revealed:` comments) closer to the tested
object.
- Always separate `# revealed` and `# error` comments from the code by
two spaces, according to the discussion
[here](https://github.com/astral-sh/ruff/pull/13746/files#r1799385758).
This trades readability for consistency in some cases.
- Fixed some headings
## Summary
Porting infer tests to new markdown tests framework.
Link to the corresponding issue: #13696
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
