Merge pull request #20587 from ChayimFriedman2/private-inherent

fix: Deduplicate methods in completion by function ID and not by name

Author: lnicola

src/tools/rust-analyzer/crates/ide-completion/src/completions/dot.rs

@@ -2,7 +2,7 @@
 
 use std::ops::ControlFlow;
 
-use hir::{Complete, HasContainer, ItemContainer, MethodCandidateCallback, Name};
+use hir::{Complete, Function, HasContainer, ItemContainer, MethodCandidateCallback};
 use ide_db::FxHashSet;
 use syntax::SmolStr;
 
@@ -237,7 +237,10 @@ fn complete_methods(
     struct Callback<'a, F> {
         ctx: &'a CompletionContext<'a>,
         f: F,
-        seen_methods: FxHashSet<Name>,
+        // We deliberately deduplicate by function ID and not name, because while inherent methods cannot be
+        // duplicated, trait methods can. And it is still useful to show all of them (even when there
+        // is also an inherent method, especially considering that it may be private, and filtered later).
+        seen_methods: FxHashSet<Function>,
     }
 
     impl<F> MethodCandidateCallback for Callback<'_, F>
@@ -247,9 +250,7 @@ fn complete_methods(
         // We don't want to exclude inherent trait methods - that is, methods of traits available from
         // `where` clauses or `dyn Trait`.
         fn on_inherent_method(&mut self, func: hir::Function) -> ControlFlow<()> {
-            if func.self_param(self.ctx.db).is_some()
-                && self.seen_methods.insert(func.name(self.ctx.db))
-            {
+            if func.self_param(self.ctx.db).is_some() && self.seen_methods.insert(func) {
                 (self.f)(func);
             }
             ControlFlow::Continue(())
@@ -265,9 +266,7 @@ fn complete_methods(
                 return ControlFlow::Continue(());
             }
 
-            if func.self_param(self.ctx.db).is_some()
-                && self.seen_methods.insert(func.name(self.ctx.db))
-            {
+            if func.self_param(self.ctx.db).is_some() && self.seen_methods.insert(func) {
                 (self.f)(func);
             }
 

src/tools/rust-analyzer/crates/ide-completion/src/tests/expression.rs

@@ -2632,3 +2632,43 @@ fn let_in_condition() {
 fn let_in_let_chain() {
     check_edit("let", r#"fn f() { if true && $0 {} }"#, r#"fn f() { if true && let $1 = $0 {} }"#);
 }
+
+#[test]
+fn private_inherent_and_public_trait() {
+    check(
+        r#"
+struct Foo;
+
+mod private {
+    impl super::Foo {
+        fn method(&self) {}
+    }
+}
+
+trait Trait {
+    fn method(&self) {}
+}
+impl Trait for Foo {}
+
+fn main() {
+    Foo.$0
+}
+    "#,
+        expect![[r#"
+            me method() (as Trait) fn(&self)
+            sn box            Box::new(expr)
+            sn call           function(expr)
+            sn const                const {}
+            sn dbg                dbg!(expr)
+            sn dbgr              dbg!(&expr)
+            sn deref                   *expr
+            sn let                       let
+            sn letm                  let mut
+            sn match           match expr {}
+            sn ref                     &expr
+            sn refm                &mut expr
+            sn return            return expr
+            sn unsafe              unsafe {}
+        "#]],
+    );
+}