From 8b078986dc2453f0dbe27f0e77fe8f8a511fe4c0 Mon Sep 17 00:00:00 2001
From: Lukas Wirth <lukastw97@gmail.com>
Date: Mon, 20 Jun 2022 20:22:51 +0200
Subject: [PATCH] Reimplement auto-ref completions for fields

---
 crates/ide-completion/src/completions.rs        |  2 ++
 crates/ide-completion/src/completions/dot.rs    | 16 ++++++++++++++--
 crates/ide-completion/src/completions/record.rs | 14 ++++++++++++--
 crates/ide-completion/src/render.rs             | 15 +++++++--------
 4 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/crates/ide-completion/src/completions.rs b/crates/ide-completion/src/completions.rs
index 750b022259..147563ef10 100644
--- a/crates/ide-completion/src/completions.rs
+++ b/crates/ide-completion/src/completions.rs
@@ -379,6 +379,7 @@ impl Completions {
     pub(crate) fn add_field(
         &mut self,
         ctx: &CompletionContext,
+        dot_access: &DotAccess,
         receiver: Option<hir::Name>,
         field: hir::Field,
         ty: &hir::Type,
@@ -390,6 +391,7 @@ impl Completions {
         };
         let item = render_field(
             RenderContext::new(ctx).private_editable(is_private_editable),
+            dot_access,
             receiver,
             field,
             ty,
diff --git a/crates/ide-completion/src/completions/dot.rs b/crates/ide-completion/src/completions/dot.rs
index b58a9f39f2..bf0bce2198 100644
--- a/crates/ide-completion/src/completions/dot.rs
+++ b/crates/ide-completion/src/completions/dot.rs
@@ -29,7 +29,7 @@ pub(crate) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext, dot_a
             acc,
             ctx,
             &receiver_ty,
-            |acc, field, ty| acc.add_field(ctx, None, field, &ty),
+            |acc, field, ty| acc.add_field(ctx, dot_access, None, field, &ty),
             |acc, field, ty| acc.add_tuple_field(ctx, None, field, &ty),
         );
     }
@@ -64,7 +64,19 @@ pub(crate) fn complete_undotted_self(
         acc,
         ctx,
         &ty,
-        |acc, field, ty| acc.add_field(ctx, Some(hir::known::SELF_PARAM), field, &ty),
+        |acc, field, ty| {
+            acc.add_field(
+                ctx,
+                &DotAccess {
+                    receiver: None,
+                    receiver_ty: None,
+                    kind: DotAccessKind::Field { receiver_is_ambiguous_float_literal: false },
+                },
+                Some(hir::known::SELF_PARAM),
+                field,
+                &ty,
+            )
+        },
         |acc, field, ty| acc.add_tuple_field(ctx, Some(hir::known::SELF_PARAM), field, &ty),
     );
     complete_methods(ctx, &ty, |func| {
diff --git a/crates/ide-completion/src/completions/record.rs b/crates/ide-completion/src/completions/record.rs
index 9f834e1ca1..8cef3a7018 100644
--- a/crates/ide-completion/src/completions/record.rs
+++ b/crates/ide-completion/src/completions/record.rs
@@ -3,7 +3,7 @@ use ide_db::SymbolKind;
 use syntax::ast::{self, Expr};
 
 use crate::{
-    context::{ExprCtx, PathCompletionCtx, PatternContext, Qualified},
+    context::{DotAccess, DotAccessKind, ExprCtx, PathCompletionCtx, PatternContext, Qualified},
     CompletionContext, CompletionItem, CompletionItemKind, CompletionRelevance,
     CompletionRelevancePostfixMatch, Completions,
 };
@@ -107,7 +107,17 @@ fn complete_fields(
     missing_fields: Vec<(hir::Field, hir::Type)>,
 ) {
     for (field, ty) in missing_fields {
-        acc.add_field(ctx, None, field, &ty);
+        acc.add_field(
+            ctx,
+            &DotAccess {
+                receiver: None,
+                receiver_ty: None,
+                kind: DotAccessKind::Field { receiver_is_ambiguous_float_literal: false },
+            },
+            None,
+            field,
+            &ty,
+        );
     }
 }
 
diff --git a/crates/ide-completion/src/render.rs b/crates/ide-completion/src/render.rs
index c29a50dd63..6571e67352 100644
--- a/crates/ide-completion/src/render.rs
+++ b/crates/ide-completion/src/render.rs
@@ -17,7 +17,7 @@ use ide_db::{
 use syntax::{AstNode, SmolStr, SyntaxKind, TextRange};
 
 use crate::{
-    context::{PathCompletionCtx, PathKind, PatternContext},
+    context::{DotAccess, PathCompletionCtx, PathKind, PatternContext},
     item::{Builder, CompletionRelevanceTypeMatch},
     render::{
         function::render_fn,
@@ -110,6 +110,7 @@ impl<'a> RenderContext<'a> {
 
 pub(crate) fn render_field(
     ctx: RenderContext<'_>,
+    dot_access: &DotAccess,
     receiver: Option<hir::Name>,
     field: hir::Field,
     ty: &hir::Type,
@@ -134,10 +135,10 @@ pub(crate) fn render_field(
     if is_keyword && !matches!(name.as_str(), "self" | "crate" | "super" | "Self") {
         item.insert_text(format!("r#{}", name));
     }
-    if let Some(_ref_match) = compute_ref_match(ctx.completion, ty) {
-        // FIXME
-        // For now we don't properly calculate the edits for ref match
-        // completions on struct fields, so we've disabled them. See #8058.
+    if let Some(receiver) = &dot_access.receiver {
+        if let Some(ref_match) = compute_ref_match(ctx.completion, ty) {
+            item.ref_match(ref_match, receiver.syntax().text_range().start());
+        }
     }
     item.build()
 }
@@ -1535,9 +1536,6 @@ impl Foo { fn baz(&self) -> u32 { 0 } }
 fn foo(f: Foo) { let _: &u32 = f.b$0 }
 "#,
             &[CompletionItemKind::Method, CompletionItemKind::SymbolKind(SymbolKind::Field)],
-            // FIXME
-            // Ideally we'd also suggest &f.bar as exact
-            // type matches. See #8058.
             expect![[r#"
                 [
                     CompletionItem {
@@ -1559,6 +1557,7 @@ fn foo(f: Foo) { let _: &u32 = f.b$0 }
                             Field,
                         ),
                         detail: "u32",
+                        ref_match: "&@96",
                     },
                 ]
             "#]],