From 99f1e66997798fdf7895ac58fc07ccb714545d88 Mon Sep 17 00:00:00 2001
From: Lukas Wirth <lukastw97@gmail.com>
Date: Sun, 29 Aug 2021 00:45:55 +0200
Subject: [PATCH] Only report unique text ranges in highlight_related

---
 crates/hir/src/semantics.rs         |  2 ++
 crates/ide/src/highlight_related.rs | 14 +++++---------
 crates/ide_db/src/search.rs         |  2 +-
 3 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index cb1efb90ab97..a0859dd1ecc7 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -538,6 +538,8 @@ impl<'db> SemanticsImpl<'db> {
         res
     }
 
+    // Note this return type is deliberate as [`find_nodes_at_offset_with_descend`] wants to stop
+    // traversing the inner iterator when it finds a node.
     fn descend_node_at_offset(
         &self,
         node: &SyntaxNode,
diff --git a/crates/ide/src/highlight_related.rs b/crates/ide/src/highlight_related.rs
index e442cf7c4fae..67ad263fa238 100644
--- a/crates/ide/src/highlight_related.rs
+++ b/crates/ide/src/highlight_related.rs
@@ -6,7 +6,7 @@ use ide_db::{
     search::{FileReference, ReferenceAccess, SearchScope},
     RootDatabase,
 };
-use itertools::Itertools;
+use rustc_hash::FxHashSet;
 use syntax::{
     ast::{self, LoopBodyOwner},
     match_ast, AstNode, SyntaxNode, SyntaxToken, TextRange, TextSize, T,
@@ -14,6 +14,7 @@ use syntax::{
 
 use crate::{display::TryToNav, references, NavigationTarget};
 
+#[derive(PartialEq, Eq, Hash)]
 pub struct HighlightedRange {
     pub range: TextRange,
     pub access: Option<ReferenceAccess>,
@@ -100,11 +101,11 @@ fn highlight_references(
         })
     });
 
-    let res: Vec<_> = declarations.chain(usages).collect();
+    let res: FxHashSet<_> = declarations.chain(usages).collect();
     if res.is_empty() {
         None
     } else {
-        Some(res)
+        Some(res.into_iter().collect())
     }
 }
 
@@ -276,7 +277,7 @@ fn find_defs(
     sema: &Semantics<RootDatabase>,
     syntax: &SyntaxNode,
     offset: TextSize,
-) -> Vec<Definition> {
+) -> FxHashSet<Definition> {
     sema.find_nodes_at_offset_with_descend(syntax, offset)
         .flat_map(|name_like| {
             Some(match name_like {
@@ -309,7 +310,6 @@ fn find_defs(
             })
         })
         .flatten()
-        .unique()
         .collect()
 }
 
@@ -423,8 +423,6 @@ macro_rules! foo {
 
 foo!(bar$0);
   // ^^^
-  // ^^^
-  // ^^^
 fn foo() {
     let bar: bar = bar();
           // ^^^
@@ -443,7 +441,6 @@ macro_rules! foo {
 
 foo!(bar);
   // ^^^
-  // ^^^
 fn foo() {
     let bar: bar$0 = bar();
           // ^^^
@@ -873,7 +870,6 @@ fn function(field: u32) {
           //^^^^^
     Struct { field$0 }
            //^^^^^ read
-           //^^^^^ read
 }
 "#,
         );
diff --git a/crates/ide_db/src/search.rs b/crates/ide_db/src/search.rs
index b125d1666f07..855675be421a 100644
--- a/crates/ide_db/src/search.rs
+++ b/crates/ide_db/src/search.rs
@@ -61,7 +61,7 @@ pub struct FileReference {
     pub access: Option<ReferenceAccess>,
 }
 
-#[derive(Debug, Copy, Clone, PartialEq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum ReferenceAccess {
     Read,
     Write,