Auto merge of rust-lang#12898 - Veykril:compl-pat-brace, r=Veykril

fix: Fix pattern completions adding unnecessary braces

Fixes rust-lang/rust-analyzer#12852

Author: bors

crates/ide-completion/src/completions.rs

@@ -400,7 +400,7 @@ impl Completions {
     ) {
         if let PathCompletionCtx { kind: PathKind::Pat { pat_ctx }, .. } = path_ctx {
             cov_mark::hit!(enum_variant_pattern_path);
-            self.add_variant_pat(ctx, pat_ctx, variant, local_name);
+            self.add_variant_pat(ctx, pat_ctx, Some(path_ctx), variant, local_name);
             return;
         }
 
@@ -484,12 +484,14 @@ impl Completions {
         &mut self,
         ctx: &CompletionContext<'_>,
         pattern_ctx: &PatternContext,
+        path_ctx: Option<&PathCompletionCtx>,
         variant: hir::Variant,
         local_name: Option<hir::Name>,
     ) {
         self.add_opt(render_variant_pat(
             RenderContext::new(ctx),
             pattern_ctx,
+            path_ctx,
             variant,
             local_name.clone(),
             None,
@@ -504,7 +506,14 @@ impl Completions {
         path: hir::ModPath,
     ) {
         let path = Some(&path);
-        self.add_opt(render_variant_pat(RenderContext::new(ctx), pattern_ctx, variant, None, path));
+        self.add_opt(render_variant_pat(
+            RenderContext::new(ctx),
+            pattern_ctx,
+            None,
+            variant,
+            None,
+            path,
+        ));
     }
 
     pub(crate) fn add_struct_pat(

crates/ide-completion/src/completions/pattern.rs

@@ -74,7 +74,7 @@ pub(crate) fn complete_pattern(
                 hir::ModuleDef::Variant(variant)
                     if refutable || single_variant_enum(variant.parent_enum(ctx.db)) =>
                 {
-                    acc.add_variant_pat(ctx, pattern_ctx, variant, Some(name.clone()));
+                    acc.add_variant_pat(ctx, pattern_ctx, None, variant, Some(name.clone()));
                     true
                 }
                 hir::ModuleDef::Adt(hir::Adt::Enum(e)) => refutable || single_variant_enum(e),

crates/ide-completion/src/render/pattern.rs

@@ -6,7 +6,7 @@ use itertools::Itertools;
 use syntax::SmolStr;
 
 use crate::{
-    context::{ParamContext, ParamKind, PatternContext},
+    context::{ParamContext, ParamKind, PathCompletionCtx, PatternContext},
     render::{
         variant::{format_literal_label, visible_fields},
         RenderContext,
@@ -42,6 +42,7 @@ pub(crate) fn render_struct_pat(
 pub(crate) fn render_variant_pat(
     ctx: RenderContext<'_>,
     pattern_ctx: &PatternContext,
+    path_ctx: Option<&PathCompletionCtx>,
     variant: hir::Variant,
     local_name: Option<Name>,
     path: Option<&hir::ModPath>,
@@ -58,9 +59,23 @@ pub(crate) fn render_variant_pat(
             (name.to_smol_str(), name.escaped().to_smol_str())
         }
     };
-    let kind = variant.kind(ctx.db());
-    let label = format_literal_label(name.as_str(), kind);
-    let pat = render_pat(&ctx, pattern_ctx, &escaped_name, kind, &visible_fields, fields_omitted)?;
+
+    let (label, pat) = match path_ctx {
+        Some(PathCompletionCtx { has_call_parens: true, .. }) => (name, escaped_name.to_string()),
+        _ => {
+            let kind = variant.kind(ctx.db());
+            let label = format_literal_label(name.as_str(), kind);
+            let pat = render_pat(
+                &ctx,
+                pattern_ctx,
+                &escaped_name,
+                kind,
+                &visible_fields,
+                fields_omitted,
+            )?;
+            (label, pat)
+        }
+    };
 
     Some(build_completion(ctx, label, pat, variant))
 }

crates/ide-completion/src/tests/pattern.rs

@@ -443,7 +443,7 @@ fn foo() {
 }
 "#,
         expect![[r#"
-            bn TupleVariant(…) TupleVariant($1)$0
+            bn TupleVariant TupleVariant
         "#]],
     );
     check_empty(
@@ -458,7 +458,7 @@ fn foo() {
 }
 "#,
         expect![[r#"
-            bn RecordVariant {…} RecordVariant { field$1 }$0
+            bn RecordVariant RecordVariant
         "#]],
     );
 }