[red-knot] fix building unions with literals and AlwaysTruthy/AlwaysFalsy #17451

carljm · 2025-04-17T17:32:21Z

In #17403 I added a comment asserting that all same-kind literal types share all the same super-types. This is true, with two notable exceptions: the types AlwaysTruthy and AlwaysFalsy. These two types are super-types of some literal types within a given kind and not others: Literal[0], Literal[""], and Literal[b""] inhabit AlwaysFalsy, while other literals inhabit AlwaysTruthy.

This PR updates the literal-unions optimization to handle these types correctly.

Fixes #17447

Verified locally that QUICKCHECK_TESTS=100000 cargo test -p red_knot_python_semantic -- --ignored types::property_tests::stable now passes again.

…alsy

github-actions · 2025-04-17T17:34:26Z

`mypy_primer` results

No ecosystem changes detected ✅

carljm · 2025-04-18T15:19:55Z

I'm going to go ahead and land this sans review, to get the property tests green again. Post-land review welcome!

dcreager

Looks good!

* main: [red-knot] fix building unions with literals and AlwaysTruthy/AlwaysFalsy (#17451) [red-knot] Type narrowing for assertions (take 2) (#17345)

dcreager · 2025-04-18T15:45:11Z

This added a test regression on main, since the new mdtests use a type statement, which isn't available until 3.12. I've got a fix (0b116e5) ready to go on #17434, which I am about to merge once CI (hopefully) goes green.

carljm · 2025-04-18T15:47:18Z

Huh, why didn't that show up on the PR CI? Did we recently change our default Python version on main? Thanks for fixing!

AlexWaygood · 2025-04-18T15:48:47Z

Just a merge race with 9c47b6d, I think!

carljm · 2025-04-18T15:48:58Z

Oh right, of course!

dcreager · 2025-04-18T15:50:54Z

Huh, why didn't that show up on the PR CI? Did we recently change our default Python version on main? Thanks for fixing!

@ntBre added version-related syntax errors after the point on main where you had branched from: #16379

* main: (123 commits) [red-knot] Handle explicit class specialization in type expressions (#17434) [red-knot] allow assignment expression in call compare narrowing (#17461) [red-knot] fix building unions with literals and AlwaysTruthy/AlwaysFalsy (#17451) [red-knot] Type narrowing for assertions (take 2) (#17345) [red-knot] class bases are not affected by __future__.annotations (#17456) [red-knot] Add support for overloaded functions (#17366) [`pyupgrade`] Add fix safety section to docs (`UP036`) (#17444) [red-knot] more type-narrowing in match statements (#17302) [red-knot] Add some narrowing for assignment expressions (#17448) [red-knot] Understand `typing.Protocol` and `typing_extensions.Protocol` as equivalent (#17446) Server: Use `min` instead of `max` to limit the number of threads (#17421) [red-knot] Detect version-related syntax errors (#16379) [`pyflakes`] Add fix safety section (`F841`) (#17410) [red-knot] Add `KnownFunction` variants for `is_protocol`, `get_protocol_members` and `runtime_checkable` (#17450) Bump 0.11.6 (#17449) Auto generate `visit_source_order` (#17180) [red-knot] Initial tests for protocols (#17436) [red-knot] Dataclasses: synthesize `__init__` with proper signature (#17428) [red-knot] Dataclasses: support `order=True` (#17406) [red-knot] Super-basic generic inference at call sites (#17301) ...

AlexWaygood · 2025-04-19T16:56:34Z

@carljm I'm not sure this PR fixed things. #17478 seems to be this same issue repeating itself :(

Verified locally that QUICKCHECK_TESTS=100000 cargo test -p red_knot_python_semantic -- --ignored types::property_tests::stable now passes again.

Huh -- if I checkout this commit, the property tests still fail for me locally. 100,000 might not be enough iterations to reliably check whether the tests are likely to be flaky -- I usually run them with QUICKCHECK_TESTS=1000000 these days:

HEAD is now at 84d064a14 [red-knot] fix building unions with literals and AlwaysTruthy/AlwaysFalsy (#17451)
~/dev/ruff (84d064a14)⚡ % QUICKCHECK_TESTS=1000000 cargo test --release -p red_knot_python_semantic -- --ignored types::property_tests::stable
   Compiling ruff_python_ast v0.0.0 (/Users/alexw/dev/ruff/crates/ruff_python_ast)
   Compiling red_knot_python_semantic v0.0.0 (/Users/alexw/dev/ruff/crates/red_knot_python_semantic)
   Compiling ruff_python_parser v0.0.0 (/Users/alexw/dev/ruff/crates/ruff_python_parser)
   Compiling ruff_python_literal v0.0.0 (/Users/alexw/dev/ruff/crates/ruff_python_literal)
   Compiling ruff_db v0.0.0 (/Users/alexw/dev/ruff/crates/ruff_db)
   Compiling red_knot_vendored v0.0.0 (/Users/alexw/dev/ruff/crates/red_knot_vendored)
   Compiling red_knot_test v0.0.0 (/Users/alexw/dev/ruff/crates/red_knot_test)
    Finished `release` profile [optimized] target(s) in 24.64s
     Running unittests src/lib.rs (target/release/deps/red_knot_python_semantic-bb028dec96527f17)

running 23 tests
test types::property_tests::stable::all_fully_static_type_pairs_are_subtype_of_their_union ... FAILED
test types::property_tests::stable::all_type_pairs_are_assignable_to_their_union ... FAILED
test types::property_tests::stable::all_fully_static_types_subtype_of_object has been running for over 60 seconds
test types::property_tests::stable::all_types_assignable_to_object has been running for over 60 seconds
test types::property_tests::stable::assignable_to_is_reflexive has been running for over 60 seconds
test types::property_tests::stable::disjoint_from_is_irreflexive has been running for over 60 seconds
test types::property_tests::stable::disjoint_from_is_symmetric has been running for over 60 seconds
test types::property_tests::stable::equivalent_to_is_reflexive has been running for over 60 seconds
test types::property_tests::stable::equivalent_to_is_symmetric has been running for over 60 seconds
test types::property_tests::stable::equivalent_to_is_transitive has been running for over 60 seconds
test types::property_tests::stable::gradual_equivalent_to_is_symmetric has been running for over 60 seconds
test types::property_tests::stable::never_assignable_to_every_type has been running for over 60 seconds
test types::property_tests::stable::never_subtype_of_every_fully_static_type has been running for over 60 seconds
test types::property_tests::stable::non_fully_static_types_do_not_participate_in_equivalence has been running for over 60 seconds
test types::property_tests::stable::never_assignable_to_every_type ... ok
test types::property_tests::stable::equivalent_to_is_reflexive ... ok
test types::property_tests::stable::never_subtype_of_every_fully_static_type ... ok
test types::property_tests::stable::assignable_to_is_reflexive ... ok
test types::property_tests::stable::non_fully_static_types_do_not_participate_in_subtyping has been running for over 60 seconds
test types::property_tests::stable::disjoint_from_is_irreflexive ... ok
test types::property_tests::stable::all_fully_static_types_subtype_of_object ... ok
test types::property_tests::stable::all_types_assignable_to_object ... ok
test types::property_tests::stable::singleton_implies_single_valued has been running for over 60 seconds
test types::property_tests::stable::singleton_implies_single_valued ... ok
test types::property_tests::stable::non_fully_static_types_do_not_participate_in_equivalence ... ok
test types::property_tests::stable::gradual_equivalent_to_is_symmetric ... ok
test types::property_tests::stable::equivalent_to_is_symmetric ... ok
test types::property_tests::stable::subtype_of_is_reflexive ... ok
test types::property_tests::stable::subtype_of_implies_assignable_to has been running for over 60 seconds
test types::property_tests::stable::subtype_of_implies_not_disjoint_from has been running for over 60 seconds
test types::property_tests::stable::subtype_of_is_antisymmetric has been running for over 60 seconds
test types::property_tests::stable::non_fully_static_types_do_not_participate_in_subtyping ... ok
test types::property_tests::stable::subtype_of_is_transitive has been running for over 60 seconds
test types::property_tests::stable::disjoint_from_is_symmetric ... ok
test types::property_tests::stable::two_equivalent_types_are_also_gradual_equivalent has been running for over 60 seconds
test types::property_tests::stable::two_gradual_equivalent_fully_static_types_are_also_equivalent has been running for over 60 seconds
test types::property_tests::stable::equivalent_to_is_transitive ... ok
test types::property_tests::stable::subtype_of_implies_assignable_to ... ok
test types::property_tests::stable::subtype_of_is_antisymmetric ... ok
test types::property_tests::stable::subtype_of_implies_not_disjoint_from ... ok
test types::property_tests::stable::two_equivalent_types_are_also_gradual_equivalent ... ok
test types::property_tests::stable::two_gradual_equivalent_fully_static_types_are_also_equivalent ... ok
test types::property_tests::stable::subtype_of_is_transitive ... ok

failures:

---- types::property_tests::stable::all_fully_static_type_pairs_are_subtype_of_their_union stdout ----

thread 'types::property_tests::stable::all_fully_static_type_pairs_are_subtype_of_their_union' panicked at /Users/alexw/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/quickcheck-1.0.3/src/tester.rs:165:28:
[quickcheck] TEST FAILED. Arguments: (Union([BytesLiteral("\0"), BytesLiteral("")]), Intersection { pos: [], neg: [BytesLiteral("")] })
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

---- types::property_tests::stable::all_type_pairs_are_assignable_to_their_union stdout ----

thread 'types::property_tests::stable::all_type_pairs_are_assignable_to_their_union' panicked at /Users/alexw/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/quickcheck-1.0.3/src/tester.rs:165:28:
[quickcheck] TEST FAILED. Arguments: (Union([BytesLiteral("\0"), BytesLiteral("")]), Intersection { pos: [], neg: [AlwaysFalsy] })


failures:
    types::property_tests::stable::all_fully_static_type_pairs_are_subtype_of_their_union
    types::property_tests::stable::all_type_pairs_are_assignable_to_their_union

test result: FAILED. 21 passed; 2 failed; 0 ignored; 0 measured; 210 filtered out; finished in 162.30s

error: test failed, to rerun pass `-p red_knot_python_semantic --lib`

## Summary #17451 was incomplete. `AlwaysFalsy` and `AlwaysTruthy` are not the only two types that are super-types of some literals (of a given kind) and not others. That set also includes intersections containing `AlwaysTruthy` or `AlwaysFalsy`, and intersections containing literal types of the same kind. Cover these cases as well. Fixes #17478. ## Test Plan Added mdtests. `QUICKCHECK_TESTS=1000000 cargo test -p red_knot_python_semantic -- --ignored types::property_tests::stable` failed on both `all_fully_static_type_pairs_are_subtypes_of_their_union` and `all_type_pairs_are_assignable_to_their_union` prior to this PR, passes after it. --------- Co-authored-by: Alex Waygood <[email protected]>

[red-knot] fix building unions with literals and AlwaysTruthy/AlwaysF…

6b65630

…alsy

carljm added the ty Multi-file analysis & type inference label Apr 17, 2025

carljm requested review from AlexWaygood, dcreager and sharkdp as code owners April 17, 2025 17:32

carljm merged commit 84d064a into main Apr 18, 2025
23 checks passed

carljm deleted the cjm/unionfix branch April 18, 2025 15:20

carljm mentioned this pull request Apr 18, 2025

Daily property test run failed on Fri Apr 18 2025 #17458

Closed

dcreager reviewed Apr 18, 2025

View reviewed changes

dcreager added a commit that referenced this pull request Apr 18, 2025

Merge branch 'main' into dcreager/subscript-types

967c8ea

* main: [red-knot] fix building unions with literals and AlwaysTruthy/AlwaysFalsy (#17451) [red-knot] Type narrowing for assertions (take 2) (#17345)

AlexWaygood mentioned this pull request Apr 20, 2025

Daily property test run failed on Sat Apr 19 2025 #17478

Closed

carljm mentioned this pull request Apr 22, 2025

[red-knot] fix unions of literals, again #17534

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[red-knot] fix building unions with literals and AlwaysTruthy/AlwaysFalsy #17451

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[red-knot] fix building unions with literals and AlwaysTruthy/AlwaysFalsy #17451

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