Extend test and fix nits

Author: jonas-schievink

src/test/ui/specialization/specialization-default-methods-fail.rs

@@ -1,11 +1,11 @@
-// compile-fail
-
-#![feature(specialization)]
+#![feature(specialization, associated_type_defaults)]
 
 // Test that attempting to override a non-default method or one not in the
-// parent impl causes an error
+// parent impl causes an error.
 
 trait Foo {
+    type Ty = ();
+    const CONST: u8 = 123;
     fn foo(&self) -> bool { true }
 }
 
@@ -16,6 +16,8 @@ trait Foo {
 // Box<i32>  Box<i64>   Vec<()>  Vec<bool>
 
 impl<T> Foo for Box<T> {
+    type Ty = bool;
+    const CONST: u8 = 0;
     fn foo(&self) -> bool { false }
 }
 
@@ -24,18 +26,26 @@ impl Foo for Box<i32> {}
 
 // Can't override a non-`default` fn
 impl Foo for Box<i64> {
+    type Ty = Vec<()>;
+//~^ error: `Ty` specializes an item from a parent `impl`, but that item is not marked `default`
+    const CONST: u8 = 42;
+//~^ error: `CONST` specializes an item from a parent `impl`, but that item is not marked `default`
     fn foo(&self) -> bool { true }
 //~^ error: `foo` specializes an item from a parent `impl`, but that item is not marked `default`
 }
 
 
-// Doesn't mention the method = provided body is used and the method is final
+// Doesn't mention the item = provided body/value is used and the method is final.
 impl<T> Foo for Vec<T> {}
 
 // Allowed
 impl Foo for Vec<()> {}
 
 impl Foo for Vec<bool> {
+    type Ty = Vec<()>;
+//~^ error: `Ty` specializes an item from a parent `impl`, but that item is not marked `default`
+    const CONST: u8 = 42;
+//~^ error: `CONST` specializes an item from a parent `impl`, but that item is not marked `default`
     fn foo(&self) -> bool { true }
 //~^ error: `foo` specializes an item from a parent `impl`, but that item is not marked `default`
 }

src/test/ui/specialization/specialization-default-methods-fail.stderr

@@ -1,7 +1,39 @@
+error[E0520]: `Ty` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/specialization-default-methods-fail.rs:29:5
+   |
+LL | / impl<T> Foo for Box<T> {
+LL | |     type Ty = bool;
+LL | |     const CONST: u8 = 0;
+LL | |     fn foo(&self) -> bool { false }
+LL | | }
+   | |_- parent `impl` is here
+...
+LL |       type Ty = Vec<()>;
+   |       ^^^^^^^^^^^^^^^^^^ cannot specialize default item `Ty`
+   |
+   = note: to specialize, `Ty` in the parent `impl` must be marked `default`
+
+error[E0520]: `CONST` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/specialization-default-methods-fail.rs:31:5
+   |
+LL | / impl<T> Foo for Box<T> {
+LL | |     type Ty = bool;
+LL | |     const CONST: u8 = 0;
+LL | |     fn foo(&self) -> bool { false }
+LL | | }
+   | |_- parent `impl` is here
+...
+LL |       const CONST: u8 = 42;
+   |       ^^^^^^^^^^^^^^^^^^^^^ cannot specialize default item `CONST`
+   |
+   = note: to specialize, `CONST` in the parent `impl` must be marked `default`
+
 error[E0520]: `foo` specializes an item from a parent `impl`, but that item is not marked `default`
-  --> $DIR/specialization-default-methods-fail.rs:27:5
+  --> $DIR/specialization-default-methods-fail.rs:33:5
    |
 LL | / impl<T> Foo for Box<T> {
+LL | |     type Ty = bool;
+LL | |     const CONST: u8 = 0;
 LL | |     fn foo(&self) -> bool { false }
 LL | | }
    | |_- parent `impl` is here
@@ -11,8 +43,30 @@ LL |       fn foo(&self) -> bool { true }
    |
    = note: to specialize, `foo` in the parent `impl` must be marked `default`
 
+error[E0520]: `Ty` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/specialization-default-methods-fail.rs:45:5
+   |
+LL | impl<T> Foo for Vec<T> {}
+   | ------------------------- parent `impl` is here
+...
+LL |     type Ty = Vec<()>;
+   |     ^^^^^^^^^^^^^^^^^^ cannot specialize default item `Ty`
+   |
+   = note: to specialize, `Ty` in the parent `impl` must be marked `default`
+
+error[E0520]: `CONST` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/specialization-default-methods-fail.rs:47:5
+   |
+LL | impl<T> Foo for Vec<T> {}
+   | ------------------------- parent `impl` is here
+...
+LL |     const CONST: u8 = 42;
+   |     ^^^^^^^^^^^^^^^^^^^^^ cannot specialize default item `CONST`
+   |
+   = note: to specialize, `CONST` in the parent `impl` must be marked `default`
+
 error[E0520]: `foo` specializes an item from a parent `impl`, but that item is not marked `default`
-  --> $DIR/specialization-default-methods-fail.rs:39:5
+  --> $DIR/specialization-default-methods-fail.rs:49:5
    |
 LL | impl<T> Foo for Vec<T> {}
    | ------------------------- parent `impl` is here
@@ -22,6 +76,6 @@ LL |     fn foo(&self) -> bool { true }
    |
    = note: to specialize, `foo` in the parent `impl` must be marked `default`
 
-error: aborting due to 2 previous errors
+error: aborting due to 6 previous errors
 
 For more information about this error, try `rustc --explain E0520`.