type-alias-enum-variants-panic: harden + describe the test.

Author: Centril

src/test/ui/type-alias-enum-variants/type-alias-enum-variants-panic.rs

@@ -1,15 +1,23 @@
 // ignore-tidy-linelength
 
+// Check that creating/matching on an enum variant through an alias with
+// the wrong braced/unit form is caught as an error.
+
 #![allow(unreachable_code)]
 
-enum Enum { Variant {} }
+enum Enum { Braced {}, Unit, Tuple() }
 type Alias = Enum;
 
 fn main() {
-    Alias::Variant;
-    //~^ ERROR expected unit struct/variant or constant, found struct variant `<Alias>::Variant` [E0533]
-    let Alias::Variant = panic!();
-    //~^ ERROR expected unit struct/variant or constant, found struct variant `<Alias>::Variant` [E0533]
-    let Alias::Variant(..) = panic!();
-    //~^ ERROR expected tuple struct/variant, found struct variant `<Alias>::Variant` [E0164]
+    Alias::Braced;
+    //~^ ERROR expected unit struct/variant or constant, found struct variant `<Alias>::Braced` [E0533]
+    let Alias::Braced = panic!();
+    //~^ ERROR expected unit struct/variant or constant, found struct variant `<Alias>::Braced` [E0533]
+    let Alias::Braced(..) = panic!();
+    //~^ ERROR expected tuple struct/variant, found struct variant `<Alias>::Braced` [E0164]
+
+    Alias::Unit();
+    //~^ ERROR expected function, found enum variant `<Alias>::Unit`
+    let Alias::Unit() = panic!();
+    //~^ ERROR expected tuple struct/variant, found unit variant `<Alias>::Unit` [E0164]
 }

src/test/ui/type-alias-enum-variants/type-alias-enum-variants-panic.stderr

@@ -1,21 +1,43 @@
-error[E0533]: expected unit struct/variant or constant, found struct variant `<Alias>::Variant`
-  --> $DIR/type-alias-enum-variants-panic.rs:9:5
+error[E0533]: expected unit struct/variant or constant, found struct variant `<Alias>::Braced`
+  --> $DIR/type-alias-enum-variants-panic.rs:12:5
    |
-LL |     Alias::Variant;
-   |     ^^^^^^^^^^^^^^
+LL |     Alias::Braced;
+   |     ^^^^^^^^^^^^^
 
-error[E0533]: expected unit struct/variant or constant, found struct variant `<Alias>::Variant`
-  --> $DIR/type-alias-enum-variants-panic.rs:11:9
+error[E0533]: expected unit struct/variant or constant, found struct variant `<Alias>::Braced`
+  --> $DIR/type-alias-enum-variants-panic.rs:14:9
    |
-LL |     let Alias::Variant = panic!();
-   |         ^^^^^^^^^^^^^^
+LL |     let Alias::Braced = panic!();
+   |         ^^^^^^^^^^^^^
 
-error[E0164]: expected tuple struct/variant, found struct variant `<Alias>::Variant`
-  --> $DIR/type-alias-enum-variants-panic.rs:13:9
+error[E0164]: expected tuple struct/variant, found struct variant `<Alias>::Braced`
+  --> $DIR/type-alias-enum-variants-panic.rs:16:9
    |
-LL |     let Alias::Variant(..) = panic!();
-   |         ^^^^^^^^^^^^^^^^^^ not a tuple variant or struct
+LL |     let Alias::Braced(..) = panic!();
+   |         ^^^^^^^^^^^^^^^^^ not a tuple variant or struct
 
-error: aborting due to 3 previous errors
+error[E0618]: expected function, found enum variant `<Alias>::Unit`
+  --> $DIR/type-alias-enum-variants-panic.rs:19:5
+   |
+LL | enum Enum { Braced {}, Unit, Tuple() }
+   |                        ---- `<Alias>::Unit` defined here
+...
+LL |     Alias::Unit();
+   |     ^^^^^^^^^^^--
+   |     |
+   |     call expression requires function
+help: `<Alias>::Unit` is a unit variant, you need to write it without the parenthesis
+   |
+LL |     <Alias>::Unit;
+   |     ^^^^^^^^^^^^^
+
+error[E0164]: expected tuple struct/variant, found unit variant `<Alias>::Unit`
+  --> $DIR/type-alias-enum-variants-panic.rs:21:9
+   |
+LL |     let Alias::Unit() = panic!();
+   |         ^^^^^^^^^^^^^ not a tuple variant or struct
+
+error: aborting due to 5 previous errors
 
-For more information about this error, try `rustc --explain E0164`.
+Some errors have detailed explanations: E0164, E0618.
+For more information about an error, try `rustc --explain E0164`.