Merge #3169

3169: Show record field names in Enum completion r=flodiebold a=adamrk

Adresses https://github.com/rust-analyzer/rust-analyzer/issues/2947.
Previously the details shown when autocompleting an Enum variant would look like the variant was a tuple even if it was a record:
![2020-02-16-15:59:32_crop](https://user-images.githubusercontent.com/16367467/74607233-64f21980-50d7-11ea-99db-e973e29c71d7.png)

This change will show the names of the fields for a record and use curly braces instead of parentheses:
![2020-02-16-15:33:00_crop](https://user-images.githubusercontent.com/16367467/74607251-8ce17d00-50d7-11ea-9d4d-38d198a4aec0.png)

This required exposing the type `adt::StructKind` from `ra_hir` and adding a function 
```
kind(self, db: &impl HirDatabase) -> StructKind
```
in the `impl` of `EnumVariant`. 

There was also a previously existing function `is_unit(self, db: &impl HirDatabase) -> bool` for `EnumVariant` which I removed because it seemed redundant after adding `kind`.

Co-authored-by: adamrk <[email protected]>

2 files changed, 6 insertions, 0 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index a56b8ab04..b6adb7589 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -3,6 +3,7 @@ use std::sync::Arc;
 
 use either::Either;
 use hir_def::{
+    adt::StructKind,
     adt::VariantData,
     builtin_type::BuiltinType,
     docs::Documentation,
@@ -424,6 +425,10 @@ impl EnumVariant {
             .collect()
     }
 
+    pub fn kind(self, db: &impl HirDatabase) -> StructKind {
+        self.variant_data(db).kind()
+    }
+
     pub(crate) fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
         db.enum_data(self.parent.id).variants[self.id].variant_data.clone()
     }
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 5cd965f7a..7a9745ebe 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -50,6 +50,7 @@ pub use crate::{
 };
 
 pub use hir_def::{
+    adt::StructKind,
     body::scope::ExprScopes,
     builtin_type::BuiltinType,
     docs::Documentation,