Merge #942

942: Hover for associated items in patterns r=matklad a=kjeremy



Co-authored-by: kjeremy <[email protected]>

2 files changed, 46 insertions, 4 deletions

diff --git a/crates/ra_ide_api/src/goto_definition.rs b/crates/ra_ide_api/src/goto_definition.rs
index 364263d9b..dd5f9f31c 100644
--- a/crates/ra_ide_api/src/goto_definition.rs
+++ b/crates/ra_ide_api/src/goto_definition.rs
@@ -100,6 +100,7 @@ pub(crate) fn reference_definition(
             }
         }
     }
+
     // Try name resolution
     let resolver = hir::source_binder::resolver_for_node(db, file_id, name_ref.syntax());
     if let Some(path) =
@@ -126,17 +127,35 @@ pub(crate) fn reference_definition(
             None => {
                 // If we failed to resolve then check associated items
                 if let Some(function) = function {
-                    // Should we do this above and then grab path from the PathExpr?
+                    // Resolve associated item for path expressions
                     if let Some(path_expr) =
                         name_ref.syntax().ancestors().find_map(ast::PathExpr::cast)
                     {
                         let infer_result = function.infer(db);
                         let source_map = function.body_source_map(db);
-                        let expr = ast::Expr::cast(path_expr.syntax()).unwrap();
+
+                        if let Some(expr) = ast::Expr::cast(path_expr.syntax()) {
+                            if let Some(res) = source_map
+                                .node_expr(expr)
+                                .and_then(|it| infer_result.assoc_resolutions_for_expr(it.into()))
+                            {
+                                return Exact(NavigationTarget::from_impl_item(db, res));
+                            }
+                        }
+                    }
+
+                    // Resolve associated item for path patterns
+                    if let Some(path_pat) =
+                        name_ref.syntax().ancestors().find_map(ast::PathPat::cast)
+                    {
+                        let infer_result = function.infer(db);
+                        let source_map = function.body_source_map(db);
+
+                        let pat: &ast::Pat = path_pat.into();
 
                         if let Some(res) = source_map
-                            .node_expr(expr)
-                            .and_then(|it| infer_result.assoc_resolutions_for_expr(it.into()))
+                            .node_pat(pat)
+                            .and_then(|it| infer_result.assoc_resolutions_for_pat(it.into()))
                         {
                             return Exact(NavigationTarget::from_impl_item(db, res));
                         }
diff --git a/crates/ra_ide_api/src/hover.rs b/crates/ra_ide_api/src/hover.rs
index bcd052c8b..638c24e31 100644
--- a/crates/ra_ide_api/src/hover.rs
+++ b/crates/ra_ide_api/src/hover.rs
@@ -534,4 +534,27 @@ mod tests {
         assert_eq!(trim_markup_opt(hover.info.first()), Some("fn new() -> Thing"));
         assert_eq!(hover.info.is_exact(), true);
     }
+
+    #[test]
+    fn test_hover_infer_associated_const_in_pattern() {
+        let (analysis, position) = single_file_with_position(
+            "
+            struct X;
+            impl X {
+                const C: u32 = 1;
+            }
+
+            fn main() {
+                match 1 {
+                    X::C<|> => {},
+                    2 => {},
+                    _ => {}
+                };
+            }
+            ",
+        );
+        let hover = analysis.hover(position).unwrap().unwrap();
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("const C: u32"));
+        assert_eq!(hover.info.is_exact(), true);
+    }
 }