Change path_exists_case_sensitive to return bool

Author: MichaReiser

crates/red_knot_python_semantic/src/module_resolver/resolver.rs

@@ -621,7 +621,6 @@ fn resolve_file_module(module: &ModulePath, resolver_state: &ResolverContext) ->
         if !system.case_sensitivity().is_case_sensitive()
             && !system
                 .path_exists_case_sensitive(path, module.search_path().as_system_path().unwrap())
-                .unwrap_or(true)
         {
             return None;
         }

crates/red_knot_server/src/system.rs

@@ -136,7 +136,7 @@ impl System for LSPSystem {
         self.os_system.canonicalize_path(path)
     }
 
-    fn path_exists_case_sensitive(&self, path: &SystemPath, prefix: &SystemPath) -> Result<bool> {
+    fn path_exists_case_sensitive(&self, path: &SystemPath, prefix: &SystemPath) -> bool {
         self.os_system.path_exists_case_sensitive(path, prefix)
     }
 

crates/red_knot_test/src/db.rs

@@ -211,11 +211,7 @@ impl System for MdtestSystem {
         self.as_system().read_virtual_path_to_notebook(path)
     }
 
-    fn path_exists_case_sensitive(
-        &self,
-        path: &SystemPath,
-        prefix: &SystemPath,
-    ) -> ruff_db::system::Result<bool> {
+    fn path_exists_case_sensitive(&self, path: &SystemPath, prefix: &SystemPath) -> bool {
         self.as_system()
             .path_exists_case_sensitive(&self.normalize_path(path), &self.normalize_path(prefix))
     }

crates/red_knot_wasm/src/lib.rs

@@ -260,12 +260,8 @@ impl System for WasmSystem {
         Err(ruff_notebook::NotebookError::Io(not_found()))
     }
 
-    fn path_exists_case_sensitive(
-        &self,
-        path: &SystemPath,
-        _prefix: &SystemPath,
-    ) -> ruff_db::system::Result<bool> {
-        Ok(self.path_exists(path))
+    fn path_exists_case_sensitive(&self, path: &SystemPath, _prefix: &SystemPath) -> bool {
+        self.path_exists(path)
     }
 
     fn case_sensitivity(&self) -> CaseSensitivity {

crates/ruff_db/src/system.rs

@@ -98,7 +98,7 @@ pub trait System: Debug {
     /// Prefix is only intended as an optimization for systems that can't efficiently check
     /// if an entire path exists with the exact casing as specified in `path`. However,
     /// implementations are allowed to check the casing of the entire path if they can do so efficiently.
-    fn path_exists_case_sensitive(&self, path: &SystemPath, prefix: &SystemPath) -> Result<bool>;
+    fn path_exists_case_sensitive(&self, path: &SystemPath, prefix: &SystemPath) -> bool;
 
     /// Returns the [`CaseSensitivity`] of the system's file system.
     fn case_sensitivity(&self) -> CaseSensitivity;

crates/ruff_db/src/system/os.rs

@@ -115,12 +115,11 @@ impl System for OsSystem {
         path.as_std_path().exists()
     }
 
-    fn path_exists_case_sensitive(&self, path: &SystemPath, prefix: &SystemPath) -> Result<bool> {
+    fn path_exists_case_sensitive(&self, path: &SystemPath, prefix: &SystemPath) -> bool {
         if self.case_sensitivity().is_case_sensitive() {
-            Ok(self.path_exists(path))
+            self.path_exists(path)
         } else {
             self.path_exists_case_sensitive_fast(path)
-                .map(Ok)
                 .unwrap_or_else(|| self.path_exists_case_sensitive_slow(path, prefix))
         }
     }
@@ -276,23 +275,30 @@ impl OsSystem {
         Some(simplified_canonicalized == simplified)
     }
 
-    fn path_exists_case_sensitive_slow(
-        &self,
-        path: &SystemPath,
-        prefix: &SystemPath,
-    ) -> Result<bool> {
+    fn path_exists_case_sensitive_slow(&self, path: &SystemPath, prefix: &SystemPath) -> bool {
         // Iterate over the sub-paths up to prefix and check if they match the casing as on disk.
         for ancestor in path.ancestors() {
             if ancestor == prefix {
                 break;
             }
 
-            if !self.inner.real_case_cache.has_name_case(ancestor)? {
-                return Ok(false);
+            match self.inner.real_case_cache.has_name_case(ancestor) {
+                Ok(true) => {
+                    // Component has correct casing, continue with next component
+                }
+                Ok(false) => {
+                    // Component has incorrect casing
+                    return false;
+                }
+                Err(_) => {
+                    // Directory doesn't exist or can't be accessed. We can assume that the file with
+                    // the given casing doesn't exist.
+                    return false;
+                }
             }
         }
 
-        Ok(true)
+        true
     }
 }
 

crates/ruff_db/src/system/test.rs

@@ -131,7 +131,7 @@ impl System for TestSystem {
         self
     }
 
-    fn path_exists_case_sensitive(&self, path: &SystemPath, prefix: &SystemPath) -> Result<bool> {
+    fn path_exists_case_sensitive(&self, path: &SystemPath, prefix: &SystemPath) -> bool {
         self.system().path_exists_case_sensitive(path, prefix)
     }
 
@@ -359,9 +359,9 @@ impl System for InMemorySystem {
     }
 
     #[inline]
-    fn path_exists_case_sensitive(&self, path: &SystemPath, _prefix: &SystemPath) -> Result<bool> {
+    fn path_exists_case_sensitive(&self, path: &SystemPath, _prefix: &SystemPath) -> bool {
         // The memory file system is case-sensitive.
-        Ok(self.path_exists(path))
+        self.path_exists(path)
     }
 
     fn case_sensitivity(&self) -> CaseSensitivity {