From 041aea2263aed03431f5e8d110c0423911e2496b Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 29 Apr 2020 11:26:21 +0200
Subject: [PATCH] Better filtering of qualified enum variants in completion

---
 .../completion/complete_unqualified_path.rs   | 12 ++++-
 crates/ra_ide/src/completion/presentation.rs  | 46 +++++++++++++++----
 2 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/crates/ra_ide/src/completion/complete_unqualified_path.rs b/crates/ra_ide/src/completion/complete_unqualified_path.rs
index f559f2b9705..a6a5568de0b 100644
--- a/crates/ra_ide/src/completion/complete_unqualified_path.rs
+++ b/crates/ra_ide/src/completion/complete_unqualified_path.rs
@@ -53,7 +53,7 @@ fn complete_enum_variants(acc: &mut Completions, ctx: &CompletionContext, ty: &T
                 // Variants with trivial paths are already added by the existing completion logic,
                 // so we should avoid adding these twice
                 if path.segments.len() > 1 {
-                    acc.add_enum_variant(ctx, variant, Some(path.to_string()));
+                    acc.add_qualified_enum_variant(ctx, variant, path);
                 }
             }
         }
@@ -1173,6 +1173,7 @@ fn main() {
                 delete: 248..250,
                 insert: "Foo::Bar",
                 kind: EnumVariant,
+                lookup: "Bar",
                 detail: "()",
             },
             CompletionItem {
@@ -1181,6 +1182,7 @@ fn main() {
                 delete: 248..250,
                 insert: "Foo::Baz",
                 kind: EnumVariant,
+                lookup: "Baz",
                 detail: "()",
             },
             CompletionItem {
@@ -1189,6 +1191,7 @@ fn main() {
                 delete: 248..250,
                 insert: "Foo::Quux",
                 kind: EnumVariant,
+                lookup: "Quux",
                 detail: "()",
             },
         ]
@@ -1231,6 +1234,7 @@ fn main() {
                 delete: 219..221,
                 insert: "Foo::Bar",
                 kind: EnumVariant,
+                lookup: "Bar",
                 detail: "()",
             },
             CompletionItem {
@@ -1239,6 +1243,7 @@ fn main() {
                 delete: 219..221,
                 insert: "Foo::Baz",
                 kind: EnumVariant,
+                lookup: "Baz",
                 detail: "()",
             },
             CompletionItem {
@@ -1247,6 +1252,7 @@ fn main() {
                 delete: 219..221,
                 insert: "Foo::Quux",
                 kind: EnumVariant,
+                lookup: "Quux",
                 detail: "()",
             },
         ]
@@ -1285,6 +1291,7 @@ fn main() {
                 delete: 185..186,
                 insert: "Foo::Bar",
                 kind: EnumVariant,
+                lookup: "Bar",
                 detail: "()",
             },
             CompletionItem {
@@ -1293,6 +1300,7 @@ fn main() {
                 delete: 185..186,
                 insert: "Foo::Baz",
                 kind: EnumVariant,
+                lookup: "Baz",
                 detail: "()",
             },
             CompletionItem {
@@ -1301,6 +1309,7 @@ fn main() {
                 delete: 185..186,
                 insert: "Foo::Quux",
                 kind: EnumVariant,
+                lookup: "Quux",
                 detail: "()",
             },
             CompletionItem {
@@ -1353,6 +1362,7 @@ fn f() -> m::E {
                 delete: 98..99,
                 insert: "m::E::V",
                 kind: EnumVariant,
+                lookup: "V",
                 detail: "()",
             },
         ]
diff --git a/crates/ra_ide/src/completion/presentation.rs b/crates/ra_ide/src/completion/presentation.rs
index 77d3543760b..2edb130cf7b 100644
--- a/crates/ra_ide/src/completion/presentation.rs
+++ b/crates/ra_ide/src/completion/presentation.rs
@@ -1,6 +1,6 @@
 //! This modules takes care of rendering various definitions as completion items.
 
-use hir::{Docs, HasAttrs, HasSource, HirDisplay, ScopeDef, StructKind, Type};
+use hir::{Docs, HasAttrs, HasSource, HirDisplay, ModPath, ScopeDef, StructKind, Type};
 use ra_syntax::ast::NameOwner;
 use stdx::SepBy;
 use test_utils::tested_by;
@@ -246,14 +246,37 @@ pub(crate) fn add_type_alias(&mut self, ctx: &CompletionContext, type_alias: hir
             .add_to(self);
     }
 
+    pub(crate) fn add_qualified_enum_variant(
+        &mut self,
+        ctx: &CompletionContext,
+        variant: hir::EnumVariant,
+        path: ModPath,
+    ) {
+        self.add_enum_variant_impl(ctx, variant, None, Some(path))
+    }
+
     pub(crate) fn add_enum_variant(
         &mut self,
         ctx: &CompletionContext,
         variant: hir::EnumVariant,
         local_name: Option<String>,
+    ) {
+        self.add_enum_variant_impl(ctx, variant, local_name, None)
+    }
+
+    fn add_enum_variant_impl(
+        &mut self,
+        ctx: &CompletionContext,
+        variant: hir::EnumVariant,
+        local_name: Option<String>,
+        path: Option<ModPath>,
     ) {
         let is_deprecated = is_deprecated(variant, ctx.db);
         let name = local_name.unwrap_or_else(|| variant.name(ctx.db).to_string());
+        let qualified_name = match &path {
+            Some(it) => it.to_string(),
+            None => name.to_string(),
+        };
         let detail_types = variant
             .fields(ctx.db)
             .into_iter()
@@ -271,16 +294,23 @@ pub(crate) fn add_enum_variant(
                 .surround_with("{ ", " }")
                 .to_string(),
         };
-        let mut res =
-            CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.clone())
-                .kind(CompletionItemKind::EnumVariant)
-                .set_documentation(variant.docs(ctx.db))
-                .set_deprecated(is_deprecated)
-                .detail(detail);
+        let mut res = CompletionItem::new(
+            CompletionKind::Reference,
+            ctx.source_range(),
+            qualified_name.clone(),
+        )
+        .kind(CompletionItemKind::EnumVariant)
+        .set_documentation(variant.docs(ctx.db))
+        .set_deprecated(is_deprecated)
+        .detail(detail);
+
+        if path.is_some() {
+            res = res.lookup_by(name);
+        }
 
         if variant_kind == StructKind::Tuple {
             let params = Params::Anonymous(variant.fields(ctx.db).len());
-            res = res.add_call_parens(ctx, name, params)
+            res = res.add_call_parens(ctx, qualified_name, params)
         }
 
         res.add_to(self);