From 1ccb31f12dd8a702acbec92960e6e47396de2221 Mon Sep 17 00:00:00 2001
From: Alex Waygood <alex.waygood@gmail.com>
Date: Fri, 16 Aug 2024 15:08:27 +0100
Subject: [PATCH] [red-knot] Use `Unknown` rather than `Unbound` for unresolved
 imports

---
 crates/red_knot_python_semantic/src/types.rs       |  6 +++++-
 crates/red_knot_python_semantic/src/types/infer.rs | 10 +++++-----
 crates/red_knot_workspace/src/lint.rs              |  4 ++--
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/crates/red_knot_python_semantic/src/types.rs b/crates/red_knot_python_semantic/src/types.rs
index e6f739df3a0096..b59d7a7f2513d3 100644
--- a/crates/red_knot_python_semantic/src/types.rs
+++ b/crates/red_knot_python_semantic/src/types.rs
@@ -113,7 +113,7 @@ pub enum Type<'db> {
     Any,
     /// the empty set of values
     Never,
-    /// unknown type (no annotation)
+    /// unknown type (either no annotation, or some kind of type error)
     /// equivalent to Any, or possibly to object in strict mode
     Unknown,
     /// name does not exist or is not bound to any value (this represents an error, but with some
@@ -145,6 +145,10 @@ impl<'db> Type<'db> {
         matches!(self, Type::Unbound)
     }
 
+    pub const fn is_unknown(&self) -> bool {
+        matches!(self, Type::Unknown)
+    }
+
     pub const fn is_never(&self) -> bool {
         matches!(self, Type::Never)
     }
diff --git a/crates/red_knot_python_semantic/src/types/infer.rs b/crates/red_knot_python_semantic/src/types/infer.rs
index 6f494f9c6bf963..7d476ea028e29e 100644
--- a/crates/red_knot_python_semantic/src/types/infer.rs
+++ b/crates/red_knot_python_semantic/src/types/infer.rs
@@ -949,7 +949,7 @@ impl<'db> TypeInferenceBuilder<'db> {
     fn module_ty_from_name(&self, module_name: Option<ModuleName>) -> Type<'db> {
         module_name
             .and_then(|module_name| resolve_module(self.db, module_name))
-            .map_or(Type::Unbound, |module| Type::Module(module.file()))
+            .map_or(Type::Unknown, |module| Type::Module(module.file()))
     }
 
     fn infer_decorator(&mut self, decorator: &ast::Decorator) -> Type<'db> {
@@ -1783,7 +1783,7 @@ mod tests {
             ("src/package/bar.py", "from .foo import X"),
         ])?;
 
-        assert_public_ty(&db, "src/package/bar.py", "X", "Unbound");
+        assert_public_ty(&db, "src/package/bar.py", "X", "Unknown");
 
         Ok(())
     }
@@ -1821,7 +1821,7 @@ mod tests {
     fn follow_nonexistent_relative_import_bare_to_package() -> anyhow::Result<()> {
         let mut db = setup_db();
         db.write_files([("src/package/bar.py", "from . import X")])?;
-        assert_public_ty(&db, "src/package/bar.py", "X", "Unbound");
+        assert_public_ty(&db, "src/package/bar.py", "X", "Unknown");
         Ok(())
     }
 
@@ -1851,7 +1851,7 @@ mod tests {
             ("src/package/bar.py", "from . import foo"),
         ])?;
 
-        assert_public_ty(&db, "src/package/bar.py", "foo", "Unbound");
+        assert_public_ty(&db, "src/package/bar.py", "foo", "Unknown");
 
         Ok(())
     }
@@ -1874,7 +1874,7 @@ mod tests {
     fn follow_nonexistent_relative_import_from_dunder_init() -> anyhow::Result<()> {
         let mut db = setup_db();
         db.write_files([("src/package/__init__.py", "from .foo import X")])?;
-        assert_public_ty(&db, "src/package/__init__.py", "X", "Unbound");
+        assert_public_ty(&db, "src/package/__init__.py", "X", "Unknown");
         Ok(())
     }
 
diff --git a/crates/red_knot_workspace/src/lint.rs b/crates/red_knot_workspace/src/lint.rs
index ba8b3e5b19be10..8aea5722e39081 100644
--- a/crates/red_knot_workspace/src/lint.rs
+++ b/crates/red_knot_workspace/src/lint.rs
@@ -129,7 +129,7 @@ fn lint_unresolved_imports(context: &SemanticLintContext, import: AnyImportRef)
             for alias in &import.names {
                 let ty = alias.ty(&context.semantic);
 
-                if ty.is_unbound() {
+                if ty.is_unknown() {
                     context.push_diagnostic(format_diagnostic(
                         context,
                         &format!("Unresolved import '{}'", &alias.name),
@@ -142,7 +142,7 @@ fn lint_unresolved_imports(context: &SemanticLintContext, import: AnyImportRef)
             for alias in &import.names {
                 let ty = alias.ty(&context.semantic);
 
-                if ty.is_unbound() {
+                if ty.is_unknown() {
                     context.push_diagnostic(format_diagnostic(
                         context,
                         &format!("Unresolved import '{}'", &alias.name),