From 971c88db809f448cada0fcdfea53051fedac84f3 Mon Sep 17 00:00:00 2001
From: Antonio Scandurra <me@as-cii.com>
Date: Tue, 4 Apr 2023 17:14:52 +0200
Subject: [PATCH] Return the previous suggestion when replacing it

---
 crates/editor/src/display_map.rs                |  9 ++++++---
 crates/editor/src/display_map/suggestion_map.rs | 17 ++++++++++++-----
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/crates/editor/src/display_map.rs b/crates/editor/src/display_map.rs
index c5e6b371ed..f54e2e980c 100644
--- a/crates/editor/src/display_map.rs
+++ b/crates/editor/src/display_map.rs
@@ -7,7 +7,7 @@ mod wrap_map;
 use crate::{Anchor, AnchorRangeExt, MultiBuffer, MultiBufferSnapshot, ToOffset, ToPoint};
 pub use block_map::{BlockMap, BlockPoint};
 use collections::{HashMap, HashSet};
-use fold_map::FoldMap;
+use fold_map::{FoldMap, FoldOffset};
 use gpui::{
     color::Color,
     fonts::{FontId, HighlightStyle},
@@ -238,19 +238,22 @@ impl DisplayMap {
         &self,
         new_suggestion: Option<Suggestion<T>>,
         cx: &mut ModelContext<Self>,
-    ) where
+    ) -> Option<Suggestion<FoldOffset>>
+    where
         T: ToPoint,
     {
         let snapshot = self.buffer.read(cx).snapshot(cx);
         let edits = self.buffer_subscription.consume().into_inner();
         let tab_size = Self::tab_size(&self.buffer, cx);
         let (snapshot, edits) = self.fold_map.read(snapshot, edits);
-        let (snapshot, edits) = self.suggestion_map.replace(new_suggestion, snapshot, edits);
+        let (snapshot, edits, old_suggestion) =
+            self.suggestion_map.replace(new_suggestion, snapshot, edits);
         let (snapshot, edits) = self.tab_map.sync(snapshot, edits, tab_size);
         let (snapshot, edits) = self
             .wrap_map
             .update(cx, |map, cx| map.sync(snapshot, edits, cx));
         self.block_map.read(snapshot, edits);
+        old_suggestion
     }
 
     pub fn set_font(&self, font_id: FontId, font_size: f32, cx: &mut ModelContext<Self>) -> bool {
diff --git a/crates/editor/src/display_map/suggestion_map.rs b/crates/editor/src/display_map/suggestion_map.rs
index ccc07bf591..17dbae6031 100644
--- a/crates/editor/src/display_map/suggestion_map.rs
+++ b/crates/editor/src/display_map/suggestion_map.rs
@@ -79,7 +79,11 @@ impl SuggestionMap {
         new_suggestion: Option<Suggestion<T>>,
         fold_snapshot: FoldSnapshot,
         fold_edits: Vec<FoldEdit>,
-    ) -> (SuggestionSnapshot, Vec<SuggestionEdit>)
+    ) -> (
+        SuggestionSnapshot,
+        Vec<SuggestionEdit>,
+        Option<Suggestion<FoldOffset>>,
+    )
     where
         T: ToPoint,
     {
@@ -99,7 +103,8 @@ impl SuggestionMap {
         let mut snapshot = self.0.lock();
 
         let mut patch = Patch::new(edits);
-        if let Some(suggestion) = snapshot.suggestion.take() {
+        let old_suggestion = snapshot.suggestion.take();
+        if let Some(suggestion) = &old_suggestion {
             patch = patch.compose([SuggestionEdit {
                 old: SuggestionOffset(suggestion.position.0)
                     ..SuggestionOffset(suggestion.position.0 + suggestion.text.len()),
@@ -119,7 +124,7 @@ impl SuggestionMap {
 
         snapshot.suggestion = new_suggestion;
         snapshot.version += 1;
-        (snapshot.clone(), patch.into_inner())
+        (snapshot.clone(), patch.into_inner(), old_suggestion)
     }
 
     pub fn sync(
@@ -589,7 +594,7 @@ mod tests {
         let (suggestion_map, suggestion_snapshot) = SuggestionMap::new(fold_snapshot.clone());
         assert_eq!(suggestion_snapshot.text(), "abcdefghi");
 
-        let (suggestion_snapshot, _) = suggestion_map.replace(
+        let (suggestion_snapshot, _, _) = suggestion_map.replace(
             Some(Suggestion {
                 position: 3,
                 text: "123\n456".into(),
@@ -854,7 +859,9 @@ mod tests {
             };
 
             log::info!("replacing suggestion with {:?}", new_suggestion);
-            self.replace(new_suggestion, fold_snapshot, Default::default())
+            let (snapshot, edits, _) =
+                self.replace(new_suggestion, fold_snapshot, Default::default());
+            (snapshot, edits)
         }
     }
 }