Move path completion to descriptors

crates/ra_analysis/src/completion/mod.rs

@@ -220,6 +220,20 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_completion_self_path() {
+        check_scope_completion(
+            r"
+            use self::m::B<|>;
+
+            mod m {
+                struct Bar;
+            }
+            ",
+            r#"[CompletionItem { label: "Bar", lookup: None, snippet: None }]"#,
+        );
+    }
+
     #[test]
     fn test_completion_mod_scope_nested() {
         check_scope_completion(

crates/ra_analysis/src/completion/reference_completion.rs

@@ -13,7 +13,7 @@ use crate::{
     descriptors::{
         module::{ModuleDescriptor},
         function::FnScopes,
-        Path, PathKind,
+        Path,
     },
     Cancelable
 };
@@ -148,9 +148,13 @@ fn complete_path(
     acc: &mut Vec<CompletionItem>,
     db: &RootDatabase,
     module: &ModuleDescriptor,
-    path: Path,
+    mut path: Path,
 ) -> Cancelable<()> {
-    let target_module = match find_target_module(module, path) {
+    if path.segments.is_empty() {
+        return Ok(());
+    }
+    path.segments.pop();
+    let target_module = match module.resolve_path(path) {
         None => return Ok(()),
         Some(it) => it,
     };
@@ -167,19 +171,6 @@ fn complete_path(
     Ok(())
 }
 
-fn find_target_module(module: &ModuleDescriptor, path: Path) -> Option<ModuleDescriptor> {
-    if path.kind != PathKind::Crate {
-        return None;
-    }
-    let mut segments = path.segments;
-    segments.pop();
-    let mut target_module = module.crate_root();
-    for name in segments {
-        target_module = target_module.child(&name)?;
-    }
-    Some(target_module)
-}
-
 fn complete_mod_item_snippets(acc: &mut Vec<CompletionItem>) {
     acc.push(CompletionItem {
         label: "tfn".to_string(),

crates/ra_analysis/src/descriptors/module/mod.rs

@@ -14,11 +14,11 @@ use relative_path::RelativePathBuf;
 
 use crate::{
     db::SyntaxDatabase, syntax_ptr::SyntaxPtr, FileId, FilePosition, Cancelable,
-    descriptors::DescriptorDatabase,
+    descriptors::{Path, PathKind, DescriptorDatabase},
     input::SourceRootId
 };
 
-pub(crate) use self::{nameres::ModuleScope};
+pub(crate) use self::nameres::ModuleScope;
 
 /// `ModuleDescriptor` is API entry point to get all the information
 /// about a particular module.
@@ -131,6 +131,19 @@ impl ModuleDescriptor {
         Ok(res)
     }
 
+    pub(crate) fn resolve_path(&self, path: Path) -> Option<ModuleDescriptor> {
+        let mut curr = match path.kind {
+            PathKind::Crate => self.crate_root(),
+            PathKind::Self_ | PathKind::Plain => self.clone(),
+            PathKind::Super => self.parent()?,
+        };
+        let segments = path.segments;
+        for name in segments {
+            curr = curr.child(&name)?;
+        }
+        Some(curr)
+    }
+
     pub fn problems(&self, db: &impl DescriptorDatabase) -> Vec<(SyntaxNode, Problem)> {
         self.module_id.problems(&self.tree, db)
     }