[ty] No union with Unknown for module-global symbols

crates/ty_python_semantic/resources/mdtest/boundness_declaredness/public.md

@@ -237,11 +237,11 @@ b: SomeUnknownName = 1  # error: [unresolved-reference]
 ```py
 from mod import a, b
 
-reveal_type(a)  # revealed: Unknown | Literal[1]
+reveal_type(a)  # revealed: int
 reveal_type(b)  # revealed: Unknown
 
 # All external modifications of `a` are allowed:
-a = None
+a = None  # error: [invalid-assignment]
 ```
 
 ### Undeclared and possibly unbound
@@ -265,11 +265,11 @@ if flag:
 # on top of this document.
 from mod import a, b
 
-reveal_type(a)  # revealed: Unknown | Literal[1]
+reveal_type(a)  # revealed: int
 reveal_type(b)  # revealed: Unknown
 
 # All external modifications of `a` are allowed:
-a = None
+a = None  # error: [invalid-assignment]
 ```
 
 ### Undeclared and unbound

crates/ty_python_semantic/resources/mdtest/del.md

@@ -108,7 +108,7 @@ def foo():
     global x
     def bar():
         # allowed, refers to `x` in the global scope
-        reveal_type(x)  # revealed: Unknown | Literal[1]
+        reveal_type(x)  # revealed: int
     bar()
     del x  # allowed, deletes `x` in the global scope (though we don't track that)
 ```

crates/ty_python_semantic/resources/mdtest/import/conditional.md

@@ -25,8 +25,8 @@ reveal_type(y)
 # error: [possibly-missing-import] "Member `y` of module `maybe_unbound` may be missing"
 from maybe_unbound import x, y
 
-reveal_type(x)  # revealed: Unknown | Literal[3]
-reveal_type(y)  # revealed: Unknown | Literal[3]
+reveal_type(x)  # revealed: int
+reveal_type(y)  # revealed: int
 ```
 
 ## Maybe unbound annotated
@@ -56,7 +56,7 @@ Importing an annotated name prefers the declared type over the inferred type:
 # error: [possibly-missing-import] "Member `y` of module `maybe_unbound_annotated` may be missing"
 from maybe_unbound_annotated import x, y
 
-reveal_type(x)  # revealed: Unknown | Literal[3]
+reveal_type(x)  # revealed: int
 reveal_type(y)  # revealed: int
 ```
 

crates/ty_python_semantic/resources/mdtest/known_constants.md

@@ -95,7 +95,7 @@ TYPE_CHECKING: bool = ...
 ```py
 from constants import TYPE_CHECKING
 
-reveal_type(TYPE_CHECKING)  # revealed: Literal[True]
+reveal_type(TYPE_CHECKING)  # revealed: bool
 
 from stub import TYPE_CHECKING
 

crates/ty_python_semantic/resources/mdtest/narrow/assignment.md

@@ -34,7 +34,7 @@ class _:
 [reveal_type(a.z) for _ in range(1)]  # revealed: Literal[0]
 
 def _():
-    reveal_type(a.x)  # revealed: Unknown | int | None
+    reveal_type(a.x)  # revealed: int | None
     reveal_type(a.y)  # revealed: Unknown | None
     reveal_type(a.z)  # revealed: Unknown | None
 
@@ -75,7 +75,7 @@ class _:
 
     if cond():
         a = A()
-    reveal_type(a.x)  # revealed: int | None | Unknown
+    reveal_type(a.x)  # revealed: int | None
     reveal_type(a.y)  # revealed: Unknown | None
     reveal_type(a.z)  # revealed: Unknown | None
 
@@ -295,10 +295,10 @@ class C:
 
 def _():
     # error: [possibly-missing-attribute]
-    reveal_type(b.a.x[0])  # revealed: Unknown | int | None
+    reveal_type(b.a.x[0])  # revealed: int | None
     # error: [possibly-missing-attribute]
-    reveal_type(b.a.x)  # revealed: Unknown | list[int | None]
-    reveal_type(b.a)  # revealed: Unknown | A | None
+    reveal_type(b.a.x)  # revealed: list[int | None]
+    reveal_type(b.a)  # revealed: A | None
 ```
 
 ## Invalid assignments are not used for narrowing

crates/ty_python_semantic/resources/mdtest/public_types.md

@@ -263,7 +263,7 @@ if flag():
     x = 1
 
     def f() -> None:
-        reveal_type(x)  # revealed: Unknown | Literal[1, 2]
+        reveal_type(x)  # revealed: int
     # Function only used inside this branch
     f()
 

crates/ty_python_semantic/src/place.rs

@@ -822,7 +822,9 @@ fn place_by_id<'db>(
                 )
             });
 
-            if scope.file(db).is_stub(db) || scope.scope(db).visibility().is_private() {
+            if scope.node(db).scope_kind().is_module() {
+                inferred.map_type(|ty| ty.promote_literals(db)).into()
+            } else if scope.file(db).is_stub(db) || scope.scope(db).visibility().is_private() {
                 // We generally trust module-level undeclared places in stubs and do not union
                 // with `Unknown`. If we don't do this, simple aliases like `IOError = OSError` in
                 // stubs would result in `IOError` being a union of `OSError` and `Unknown`, which

crates/ty_python_semantic/src/types.rs

@@ -6227,6 +6227,12 @@ impl<'db> Type<'db> {
         }
     }
 
+    /// Replaces any literal types with their corresponding promoted type form (e.g. `Literal["string"]`
+    /// to `str`, or `def _() -> int` to `Callable[[], int]`).
+    pub(crate) fn promote_literals(self, db: &'db dyn Db) -> Type<'db> {
+        self.apply_type_mapping(db, &TypeMapping::PromoteLiterals)
+    }
+
     /// Locates any legacy `TypeVar`s in this type, and adds them to a set. This is used to build
     /// up a generic context from any legacy `TypeVar`s that appear in a function parameter list or
     /// `Generic` specialization.