1 files changed, 96 insertions, 0 deletions

diff --git a/crates/hir_ty/src/tests/traits.rs b/crates/hir_ty/src/tests/traits.rs
index f7ee6def6..2ba97f814 100644
--- a/crates/hir_ty/src/tests/traits.rs
+++ b/crates/hir_ty/src/tests/traits.rs
@@ -2272,6 +2272,56 @@ fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
 }
 
 #[test]
+fn unselected_projection_in_trait_env_cycle_3() {
+    // this is a cycle for rustc; we currently accept it
+    check_types(
+        r#"
+//- /main.rs
+trait Trait {
+    type Item;
+    type OtherItem;
+}
+
+fn test<T>() where T: Trait<OtherItem = T::Item> {
+    let x: T::Item = no_matter;
+}                   //^ Trait::Item<T>
+"#,
+    );
+}
+
+#[test]
+fn unselected_projection_in_trait_env_no_cycle() {
+    // this is not a cycle
+    check_types(
+        r#"
+//- /main.rs
+trait Index {
+    type Output;
+}
+
+type Key<S: UnificationStoreBase> = <S as UnificationStoreBase>::Key;
+
+pub trait UnificationStoreBase: Index<Output = Key<Self>> {
+    type Key;
+
+    fn len(&self) -> usize;
+}
+
+pub trait UnificationStoreMut: UnificationStoreBase {
+    fn push(&mut self, value: Self::Key);
+}
+
+fn test<T>(t: T) where T: UnificationStoreMut {
+    let x;
+    t.push(x);
+    let y: Key<T>;
+    (x, y);
+}      //^ (UnificationStoreBase::Key<T>, UnificationStoreBase::Key<T>)
+"#,
+    );
+}
+
+#[test]
 fn inline_assoc_type_bounds_1() {
     check_types(
         r#"
@@ -3274,3 +3324,49 @@ fn f() {
         "#]],
     )
 }
+
+#[test]
+fn infer_default_trait_type_parameter() {
+    check_infer(
+        r#"
+struct A;
+
+trait Op<RHS=Self> {
+    type Output;
+
+    fn do_op(self, rhs: RHS) -> Self::Output;
+}
+
+impl Op for A {
+    type Output = bool;
+
+    fn do_op(self, rhs: Self) -> Self::Output {
+        true
+    }
+}
+
+fn test() {
+    let x = A;
+    let y = A;
+    let r = x.do_op(y);
+}
+        "#,
+        expect![[r#"
+            63..67 'self': Self
+            69..72 'rhs': RHS
+            153..157 'self': A
+            159..162 'rhs': A
+            186..206 '{     ...     }': bool
+            196..200 'true': bool
+            220..277 '{     ...(y); }': ()
+            230..231 'x': A
+            234..235 'A': A
+            245..246 'y': A
+            249..250 'A': A
+            260..261 'r': bool
+            264..265 'x': A
+            264..274 'x.do_op(y)': bool
+            272..273 'y': A
+        "#]],
+    )
+}