complete fields in enum variants

crates/ra_ide_api/src/completion/complete_struct_literal.rs

@@ -1,28 +1,24 @@
-use hir::AdtDef;
+use hir::{Substs, Ty};
 
 use crate::completion::{CompletionContext, Completions};
 
 /// Complete fields in fields literals.
 pub(super) fn complete_struct_literal(acc: &mut Completions, ctx: &CompletionContext) {
-    let ty = match ctx.struct_lit_syntax.and_then(|it| ctx.analyzer.type_of(ctx.db, it.into())) {
+    let (ty, variant) = match ctx.struct_lit_syntax.and_then(|it| {
+        Some((ctx.analyzer.type_of(ctx.db, it.into())?, ctx.analyzer.resolve_variant(it)?))
+    }) {
         Some(it) => it,
-        None => return,
-    };
-    let (adt, substs) = match ty.as_adt() {
-        Some(res) => res,
         _ => return,
     };
-    match adt {
-        AdtDef::Struct(s) => {
-            for field in s.fields(ctx.db) {
-                acc.add_field(ctx, field, substs);
-            }
-        }
 
-        // FIXME unions
-        AdtDef::Union(_) => (),
-        AdtDef::Enum(_) => (),
+    let ty_substs = match ty {
+        Ty::Apply(it) => it.parameters,
+        _ => Substs::empty(),
     };
+
+    for field in variant.fields(ctx.db) {
+        acc.add_field(ctx, field, &ty_substs);
+    }
 }
 
 #[cfg(test)]
@@ -57,4 +53,81 @@ mod tests {
        ⋮]
         "###);
     }
+
+    #[test]
+    fn test_struct_literal_enum_variant() {
+        let completions = complete(
+            r"
+            enum E {
+                A { a: u32 }
+            }
+            fn foo() {
+                let _ = E::A { <|> }
+            }
+            ",
+        );
+        assert_debug_snapshot_matches!(completions, @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "a",
+       ⋮        source_range: [119; 119),
+       ⋮        delete: [119; 119),
+       ⋮        insert: "a",
+       ⋮        kind: Field,
+       ⋮        detail: "u32",
+       ⋮    },
+       ⋮]
+        "###);
+    }
+
+    #[test]
+    fn test_struct_literal_two_structs() {
+        let completions = complete(
+            r"
+            struct A { a: u32 }
+            struct B { b: u32 }
+
+            fn foo() {
+               let _: A = B { <|> }
+            }
+            ",
+        );
+        assert_debug_snapshot_matches!(completions, @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "b",
+       ⋮        source_range: [119; 119),
+       ⋮        delete: [119; 119),
+       ⋮        insert: "b",
+       ⋮        kind: Field,
+       ⋮        detail: "u32",
+       ⋮    },
+       ⋮]
+        "###);
+    }
+
+    #[test]
+    fn test_struct_literal_generic_struct() {
+        let completions = complete(
+            r"
+            struct A<T> { a: T }
+
+            fn foo() {
+               let _: A<u32> = A { <|> }
+            }
+            ",
+        );
+        assert_debug_snapshot_matches!(completions, @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "a",
+       ⋮        source_range: [93; 93),
+       ⋮        delete: [93; 93),
+       ⋮        insert: "a",
+       ⋮        kind: Field,
+       ⋮        detail: "u32",
+       ⋮    },
+       ⋮]
+        "###);
+    }
 }