[red-knot] Migrate is_fully_static/is_single_valued/`is_singleton…

…` unit tests to Markdown tests (#15533)

## Summary

Part of #15397.

## Test Plan

Markdown tests.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

crates/red_knot_python_semantic/resources/mdtest/type_properties/is_fully_static.md

@@ -0,0 +1,54 @@
+# Fully-static types
+
+A type is fully static iff it does not contain any gradual forms.
+
+## Fully-static
+
+```py
+from typing_extensions import Literal, LiteralString, Never
+from knot_extensions import Intersection, Not, TypeOf, is_fully_static, static_assert
+
+static_assert(is_fully_static(Never))
+static_assert(is_fully_static(None))
+
+static_assert(is_fully_static(Literal[1]))
+static_assert(is_fully_static(Literal[True]))
+static_assert(is_fully_static(Literal["abc"]))
+static_assert(is_fully_static(Literal[b"abc"]))
+
+static_assert(is_fully_static(LiteralString))
+
+static_assert(is_fully_static(str))
+static_assert(is_fully_static(object))
+static_assert(is_fully_static(type))
+
+static_assert(is_fully_static(TypeOf[str]))
+static_assert(is_fully_static(TypeOf[Literal]))
+
+static_assert(is_fully_static(str | None))
+static_assert(is_fully_static(Intersection[str, Not[LiteralString]]))
+
+static_assert(is_fully_static(tuple[()]))
+static_assert(is_fully_static(tuple[int, object]))
+
+static_assert(is_fully_static(type[str]))
+static_assert(is_fully_static(type[object]))
+```
+
+## Non-fully-static
+
+```py
+from typing_extensions import Any, Literal, LiteralString
+from knot_extensions import Intersection, Not, TypeOf, Unknown, is_fully_static, static_assert
+
+static_assert(not is_fully_static(Any))
+static_assert(not is_fully_static(Unknown))
+
+static_assert(not is_fully_static(Any | str))
+static_assert(not is_fully_static(str | Unknown))
+static_assert(not is_fully_static(Intersection[Any, Not[LiteralString]]))
+
+static_assert(not is_fully_static(tuple[Any, ...]))
+static_assert(not is_fully_static(tuple[int, Any]))
+static_assert(not is_fully_static(type[Any]))
+```

crates/red_knot_python_semantic/resources/mdtest/type_properties/is_single_valued.md

@@ -0,0 +1,25 @@
+## Single-valued types
+
+A type is single-valued iff it is not empty and all inhabitants of it compare equal.
+
+```py
+from typing_extensions import Any, Literal, LiteralString, Never
+from knot_extensions import is_single_valued, static_assert
+
+static_assert(is_single_valued(None))
+static_assert(is_single_valued(Literal[True]))
+static_assert(is_single_valued(Literal[1]))
+static_assert(is_single_valued(Literal["abc"]))
+static_assert(is_single_valued(Literal[b"abc"]))
+
+static_assert(is_single_valued(tuple[()]))
+static_assert(is_single_valued(tuple[Literal[True], Literal[1]]))
+
+static_assert(not is_single_valued(str))
+static_assert(not is_single_valued(Never))
+static_assert(not is_single_valued(Any))
+
+static_assert(not is_single_valued(Literal[1, 2]))
+
+static_assert(not is_single_valued(tuple[None, int]))
+```

crates/red_knot_python_semantic/resources/mdtest/type_properties/is_singleton.md

@@ -0,0 +1,56 @@
+# Singleton types
+
+A type is a singleton type iff it has exactly one inhabitant.
+
+## Basic
+
+```py
+from typing_extensions import Literal, Never
+from knot_extensions import is_singleton, static_assert
+
+static_assert(is_singleton(None))
+static_assert(is_singleton(Literal[True]))
+static_assert(is_singleton(Literal[False]))
+
+static_assert(is_singleton(type[bool]))
+
+static_assert(not is_singleton(Never))
+static_assert(not is_singleton(str))
+
+static_assert(not is_singleton(Literal[345]))
+static_assert(not is_singleton(Literal[1, 2]))
+
+static_assert(not is_singleton(tuple[()]))
+static_assert(not is_singleton(tuple[None]))
+static_assert(not is_singleton(tuple[None, Literal[True]]))
+```
+
+## `NoDefault`
+
+### 3.12
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+from typing_extensions import _NoDefaultType
+from knot_extensions import is_singleton, static_assert
+
+static_assert(is_singleton(_NoDefaultType))
+```
+
+### 3.13
+
+```toml
+[environment]
+python-version = "3.13"
+```
+
+```py
+from typing import _NoDefaultType
+from knot_extensions import is_singleton, static_assert
+
+static_assert(is_singleton(_NoDefaultType))
+```

crates/red_knot_python_semantic/src/types.rs

@@ -4533,16 +4533,6 @@ pub(crate) mod tests {
         ));
     }
 
-    #[test_case(Ty::None)]
-    #[test_case(Ty::BooleanLiteral(true))]
-    #[test_case(Ty::BooleanLiteral(false))]
-    #[test_case(Ty::SubclassOfBuiltinClass("bool"))] // a `@final` class
-    fn is_singleton(from: Ty) {
-        let db = setup_db();
-
-        assert!(from.into_type(&db).is_singleton(&db));
-    }
-
     /// Explicitly test for Python version <3.13 and >=3.13, to ensure that
     /// the fallback to `typing_extensions` is working correctly.
     /// See [`KnownClass::canonical_module`] for more information.
@@ -4559,83 +4549,6 @@ pub(crate) mod tests {
         assert!(no_default.is_singleton(&db));
     }
 
-    #[test_case(Ty::None)]
-    #[test_case(Ty::BooleanLiteral(true))]
-    #[test_case(Ty::IntLiteral(1))]
-    #[test_case(Ty::StringLiteral("abc"))]
-    #[test_case(Ty::BytesLiteral("abc"))]
-    #[test_case(Ty::Tuple(vec![]))]
-    #[test_case(Ty::Tuple(vec![Ty::BooleanLiteral(true), Ty::IntLiteral(1)]))]
-    fn is_single_valued(from: Ty) {
-        let db = setup_db();
-
-        assert!(from.into_type(&db).is_single_valued(&db));
-    }
-
-    #[test_case(Ty::Never)]
-    #[test_case(Ty::Any)]
-    #[test_case(Ty::Union(vec![Ty::IntLiteral(1), Ty::IntLiteral(2)]))]
-    #[test_case(Ty::Tuple(vec![Ty::None, Ty::BuiltinInstance("int")]))]
-    #[test_case(Ty::BuiltinInstance("str"))]
-    #[test_case(Ty::LiteralString)]
-    fn is_not_single_valued(from: Ty) {
-        let db = setup_db();
-
-        assert!(!from.into_type(&db).is_single_valued(&db));
-    }
-
-    #[test_case(Ty::Never)]
-    #[test_case(Ty::IntLiteral(345))]
-    #[test_case(Ty::BuiltinInstance("str"))]
-    #[test_case(Ty::Union(vec![Ty::IntLiteral(1), Ty::IntLiteral(2)]))]
-    #[test_case(Ty::Tuple(vec![]))]
-    #[test_case(Ty::Tuple(vec![Ty::None]))]
-    #[test_case(Ty::Tuple(vec![Ty::None, Ty::BooleanLiteral(true)]))]
-    fn is_not_singleton(from: Ty) {
-        let db = setup_db();
-
-        assert!(!from.into_type(&db).is_singleton(&db));
-    }
-
-    #[test_case(Ty::Never)]
-    #[test_case(Ty::None)]
-    #[test_case(Ty::IntLiteral(1))]
-    #[test_case(Ty::BooleanLiteral(true))]
-    #[test_case(Ty::StringLiteral("abc"))]
-    #[test_case(Ty::LiteralString)]
-    #[test_case(Ty::BytesLiteral("abc"))]
-    #[test_case(Ty::KnownClassInstance(KnownClass::Str))]
-    #[test_case(Ty::KnownClassInstance(KnownClass::Object))]
-    #[test_case(Ty::KnownClassInstance(KnownClass::Type))]
-    #[test_case(Ty::BuiltinClassLiteral("str"))]
-    #[test_case(Ty::TypingLiteral)]
-    #[test_case(Ty::Union(vec![Ty::KnownClassInstance(KnownClass::Str), Ty::None]))]
-    #[test_case(Ty::Intersection{pos: vec![Ty::KnownClassInstance(KnownClass::Str)], neg: vec![Ty::LiteralString]})]
-    #[test_case(Ty::Tuple(vec![]))]
-    #[test_case(Ty::Tuple(vec![Ty::KnownClassInstance(KnownClass::Int), Ty::KnownClassInstance(KnownClass::Object)]))]
-    #[test_case(Ty::BuiltinInstance("type"))]
-    #[test_case(Ty::SubclassOfBuiltinClass("object"))]
-    #[test_case(Ty::SubclassOfBuiltinClass("str"))]
-    fn is_fully_static(from: Ty) {
-        let db = setup_db();
-
-        assert!(from.into_type(&db).is_fully_static(&db));
-    }
-
-    #[test_case(Ty::Any)]
-    #[test_case(Ty::Unknown)]
-    #[test_case(Ty::Todo)]
-    #[test_case(Ty::Union(vec![Ty::Any, Ty::KnownClassInstance(KnownClass::Str)]))]
-    #[test_case(Ty::Union(vec![Ty::KnownClassInstance(KnownClass::Str), Ty::Unknown]))]
-    #[test_case(Ty::Intersection{pos: vec![Ty::Any], neg: vec![Ty::LiteralString]})]
-    #[test_case(Ty::Tuple(vec![Ty::KnownClassInstance(KnownClass::Int), Ty::Any]))]
-    #[test_case(Ty::SubclassOfAny)]
-    fn is_not_fully_static(from: Ty) {
-        let db = setup_db();
-
-        assert!(!from.into_type(&db).is_fully_static(&db));
-    }
-
     #[test_case(Ty::Todo, Ty::Todo)]
     #[test_case(Ty::Any, Ty::Any)]
     #[test_case(Ty::Unknown, Ty::Unknown)]