Add missing space when expanding a struct-like variant

In `wildcard_enum_match_arm`, expanding a variant with struct-like
fields was missing a space between the variant name and the opening
bracket.

Also, add a test for tuple-like variants with only one field, as those
are expanded as `VariantName(_)` instead of `VariantName(..)`.

Author: samueltardieu

clippy_lints/src/matches/match_wild_enum.rs

@@ -140,7 +140,7 @@ pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>]) {
                 Some(CtorKind::Fn) if variant.fields.len() == 1 => "(_)",
                 Some(CtorKind::Fn) => "(..)",
                 Some(CtorKind::Const) => "",
-                None => "{ .. }",
+                None => " { .. }",
             }
         )
     };

tests/ui/wildcard_enum_match_arm.fixed

@@ -90,6 +90,21 @@ fn main() {
         _ => {},
     }
 
+    {
+        pub enum Enum {
+            A,
+            B,
+            C(u8),
+            D(u8, u8),
+            E { e: u8 },
+        };
+        match Enum::A {
+            Enum::A => (),
+            Enum::B | Enum::C(_) | Enum::D(..) | Enum::E { .. } => (),
+            //~^ wildcard_enum_match_arm
+        }
+    }
+
     {
         #![allow(clippy::manual_non_exhaustive)]
         pub enum Enum {

tests/ui/wildcard_enum_match_arm.rs

@@ -90,6 +90,21 @@ fn main() {
         _ => {},
     }
 
+    {
+        pub enum Enum {
+            A,
+            B,
+            C(u8),
+            D(u8, u8),
+            E { e: u8 },
+        };
+        match Enum::A {
+            Enum::A => (),
+            _ => (),
+            //~^ wildcard_enum_match_arm
+        }
+    }
+
     {
         #![allow(clippy::manual_non_exhaustive)]
         pub enum Enum {

tests/ui/wildcard_enum_match_arm.stderr

@@ -37,14 +37,20 @@ LL |         _ => {},
 error: wildcard match will also match any future added variants
   --> tests/ui/wildcard_enum_match_arm.rs:103:13
    |
+LL |             _ => (),
+   |             ^ help: try: `Enum::B | Enum::C(_) | Enum::D(..) | Enum::E { .. }`
+
+error: wildcard match will also match any future added variants
+  --> tests/ui/wildcard_enum_match_arm.rs:118:13
+   |
 LL |             _ => (),
    |             ^ help: try: `Enum::B | Enum::__Private`
 
 error: wildcard match will also match any future added variants
-  --> tests/ui/wildcard_enum_match_arm.rs:118:9
+  --> tests/ui/wildcard_enum_match_arm.rs:133:9
    |
 LL |         r#type => {},
    |         ^^^^^^ help: try: `r#type @ Foo::B | r#type @ Foo::C`
 
-error: aborting due to 7 previous errors
+error: aborting due to 8 previous errors