From 283ec13fc06dda7ec4d22955e2d2eb96aaff95fd Mon Sep 17 00:00:00 2001
From: vsrs <vit@conrlab.com>
Date: Wed, 10 Jun 2020 22:56:49 +0300
Subject: [PATCH] Fix type "items" order.

---
 crates/ra_hir/src/code_model.rs | 25 ++++++++++++++++-------
 crates/ra_ide/src/hover.rs      | 35 +++++++++++++++++----------------
 2 files changed, 36 insertions(+), 24 deletions(-)

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index c22eb451b96..64b9a4cc3a6 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -27,7 +27,7 @@ use hir_ty::{
     display::{HirDisplayError, HirFormatter},
     expr::ExprValidator,
     method_resolution, ApplicationTy, Canonical, GenericPredicate, InEnvironment, OpaqueTyId,
-    Substs, TraitEnvironment, Ty, TyDefId, TypeCtor, TypeWalk,
+    Substs, TraitEnvironment, Ty, TyDefId, TypeCtor,
 };
 use ra_db::{CrateId, CrateName, Edition, FileId};
 use ra_prof::profile;
@@ -1381,7 +1381,7 @@ impl Type {
         }
     }
 
-    /// Returns a flattened list of all the ADTs and Traits mentioned in the type
+    /// Returns a flattened list of all ADTs and Traits mentioned in the type
     pub fn flattened_type_items(&self, db: &dyn HirDatabase) -> Vec<AdtOrTrait> {
         fn push_new_item(item: AdtOrTrait, acc: &mut Vec<AdtOrTrait>) {
             if !acc.contains(&item) {
@@ -1398,7 +1398,7 @@ impl Type {
                 match p {
                     GenericPredicate::Implemented(trait_ref) => {
                         push_new_item(Trait::from(trait_ref.trait_).into(), acc);
-                        walk_types(db, &trait_ref.substs, acc);
+                        walk_substs(db, &trait_ref.substs, acc);
                     }
                     GenericPredicate::Projection(_) => {}
                     GenericPredicate::Error => (),
@@ -1406,8 +1406,11 @@ impl Type {
             }
         }
 
-        fn walk_types<T: TypeWalk>(db: &dyn HirDatabase, tw: &T, acc: &mut Vec<AdtOrTrait>) {
-            tw.walk(&mut |ty| walk_type(db, ty, acc));
+        // TypeWalk::walk does not preserve items order!
+        fn walk_substs(db: &dyn HirDatabase, substs: &Substs, acc: &mut Vec<AdtOrTrait>) {
+            for ty in substs.iter() {
+                walk_type(db, ty, acc);
+            }
         }
 
         fn walk_type(db: &dyn HirDatabase, ty: &Ty, acc: &mut Vec<AdtOrTrait>) {
@@ -1415,10 +1418,18 @@ impl Type {
                 Ty::Apply(ApplicationTy { ctor, parameters, .. }) => {
                     match ctor {
                         TypeCtor::Adt(adt_id) => push_new_item(Adt::from(*adt_id).into(), acc),
+                        TypeCtor::AssociatedType(type_alias_id) => {
+                            let trait_id = match type_alias_id.lookup(db.upcast()).container {
+                                AssocContainerId::TraitId(it) => it,
+                                _ => panic!("not an associated type"),
+                            };
+
+                            push_new_item(Trait::from(trait_id).into(), acc);
+                        }
                         _ => (),
                     }
                     // adt params, tuples, etc...
-                    walk_types(db, parameters, acc);
+                    walk_substs(db, parameters, acc);
                 }
                 Ty::Dyn(predicates) => {
                     push_bounds(db, predicates, acc);
@@ -1451,7 +1462,7 @@ impl Type {
                         }
                     };
                     push_bounds(db, &bounds.value, acc);
-                    walk_types(db, &opaque_ty.parameters, acc);
+                    walk_substs(db, &opaque_ty.parameters, acc);
                 }
                 _ => (),
             }
diff --git a/crates/ra_ide/src/hover.rs b/crates/ra_ide/src/hover.rs
index c434e5c8b69..c4ee2ff796b 100644
--- a/crates/ra_ide/src/hover.rs
+++ b/crates/ra_ide/src/hover.rs
@@ -234,9 +234,10 @@ fn runnable_action(
 fn goto_type_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
     match def {
         Definition::Local(it) => {
-            let ty = it.ty(db);
-            let v = ty.flattened_type_items(db);
-            let targets = v.into_iter()
+            let targets = it
+                .ty(db)
+                .flattened_type_items(db)
+                .into_iter()
                 .map(|it| HoverGotoTypeData {
                     mod_path: adt_or_trait_mod_path(db, &it),
                     nav: it.to_nav(db),
@@ -1980,7 +1981,7 @@ fn func(foo: i32) { if true { <|>foo; }; }
     }
 
     #[test]
-    fn test_hover_arg_goto_type_action() {
+    fn test_hover_goto_type_action_links_order() {
         let (_, actions) = check_hover_result(
             "
             //- /lib.rs
@@ -1988,10 +1989,10 @@ fn func(foo: i32) { if true { <|>foo; }; }
             trait DynTrait<T> {}
             struct B<T> {}
             struct S {}
-        
-            fn foo(a<|>rg: &impl ImplTrait<B<dyn DynTrait<S>>>) {}
+
+            fn foo(a<|>rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
             ",
-            &["&impl ImplTrait<B<dyn DynTrait<S>>>"],
+            &["&impl ImplTrait<B<dyn DynTrait<B<S>>>>"],
         );
         assert_debug_snapshot!(actions,
             @r###"
@@ -2018,20 +2019,20 @@ fn func(foo: i32) { if true { <|>foo; }; }
                             },
                         },
                         HoverGotoTypeData {
-                            mod_path: "S",
+                            mod_path: "B",
                             nav: NavigationTarget {
                                 file_id: FileId(
                                     1,
                                 ),
-                                full_range: 58..69,
-                                name: "S",
+                                full_range: 43..57,
+                                name: "B",
                                 kind: STRUCT_DEF,
                                 focus_range: Some(
-                                    65..66,
+                                    50..51,
                                 ),
                                 container_name: None,
                                 description: Some(
-                                    "struct S",
+                                    "struct B",
                                 ),
                                 docs: None,
                             },
@@ -2056,20 +2057,20 @@ fn func(foo: i32) { if true { <|>foo; }; }
                             },
                         },
                         HoverGotoTypeData {
-                            mod_path: "B",
+                            mod_path: "S",
                             nav: NavigationTarget {
                                 file_id: FileId(
                                     1,
                                 ),
-                                full_range: 43..57,
-                                name: "B",
+                                full_range: 58..69,
+                                name: "S",
                                 kind: STRUCT_DEF,
                                 focus_range: Some(
-                                    50..51,
+                                    65..66,
                                 ),
                                 container_name: None,
                                 description: Some(
-                                    "struct B",
+                                    "struct S",
                                 ),
                                 docs: None,
                             },