inline completion: Add syntax highlighting for edit prediction

crates/copilot/src/copilot_completion_provider.rs

@@ -256,6 +256,7 @@ impl InlineCompletionProvider for CopilotCompletionProvider {
                 let position = cursor_position.bias_right(buffer);
                 Some(InlineCompletion {
                     edits: vec![(position..position, completion_text.into())],
+                    edit_preview: None,
                 })
             }
         } else {

crates/editor/src/code_context_menus.rs

@@ -736,13 +736,13 @@ impl CompletionsMenu {
             }
             CompletionEntry::InlineCompletionHint(InlineCompletionMenuHint::Loaded { text }) => {
                 match text {
-                    InlineCompletionText::Edit { text, highlights } => div()
+                    InlineCompletionText::Edit(highlighted_edits) => div()
                         .mx_1()
                         .rounded_md()
                         .bg(cx.theme().colors().editor_background)
                         .child(
-                            gpui::StyledText::new(text.clone())
-                                .with_highlights(&style.text, highlights.clone()),
+                            gpui::StyledText::new(highlighted_edits.text.clone())
+                                .with_highlights(&style.text, highlighted_edits.highlights.clone()),
                         ),
                     InlineCompletionText::Move(text) => div().child(text.clone()),
                 }

crates/editor/src/editor.rs

@@ -100,8 +100,8 @@ use itertools::Itertools;
 use language::{
     language_settings::{self, all_language_settings, language_settings, InlayHintSettings},
     markdown, point_from_lsp, AutoindentMode, BracketPair, Buffer, Capability, CharKind, CodeLabel,
-    CursorShape, Diagnostic, Documentation, IndentKind, IndentSize, Language, OffsetRangeExt,
-    Point, Selection, SelectionGoal, TransactionId,
+    CursorShape, Diagnostic, Documentation, EditPreview, HighlightedEdits, IndentKind, IndentSize,
+    Language, OffsetRangeExt, Point, Selection, SelectionGoal, TransactionId,
 };
 use language::{point_to_lsp, BufferRow, CharClassifier, Runnable, RunnableRange};
 use linked_editing_ranges::refresh_linked_ranges;
@@ -120,6 +120,7 @@ use lsp::{
     LanguageServerId, LanguageServerName,
 };
 
+use language::BufferSnapshot;
 use movement::TextLayoutDetails;
 pub use multi_buffer::{
     Anchor, AnchorRangeExt, ExcerptId, ExcerptRange, MultiBuffer, MultiBufferSnapshot, ToOffset,
@@ -479,10 +480,7 @@ impl InlineCompletionMenuHint {
 #[derive(Clone, Debug)]
 enum InlineCompletionText {
     Move(SharedString),
-    Edit {
-        text: SharedString,
-        highlights: Vec<(Range<usize>, HighlightStyle)>,
-    },
+    Edit(HighlightedEdits),
 }
 
 pub(crate) enum EditDisplayMode {
@@ -494,7 +492,9 @@ pub(crate) enum EditDisplayMode {
 enum InlineCompletion {
     Edit {
         edits: Vec<(Range<Anchor>, String)>,
+        edit_preview: Option<EditPreview>,
         display_mode: EditDisplayMode,
+        snapshot: BufferSnapshot,
     },
     Move(Anchor),
 }
@@ -4695,10 +4695,7 @@ impl Editor {
                     selections.select_anchor_ranges([position..position]);
                 });
             }
-            InlineCompletion::Edit {
-                edits,
-                display_mode: _,
-            } => {
+            InlineCompletion::Edit { edits, .. } => {
                 if let Some(provider) = self.inline_completion_provider() {
                     provider.accept(cx);
                 }
@@ -4745,10 +4742,7 @@ impl Editor {
                     selections.select_anchor_ranges([position..position]);
                 });
             }
-            InlineCompletion::Edit {
-                edits,
-                display_mode: _,
-            } => {
+            InlineCompletion::Edit { edits, .. } => {
                 // Find an insertion that starts at the cursor position.
                 let snapshot = self.buffer.read(cx).snapshot(cx);
                 let cursor_offset = self.selections.newest::<usize>(cx).head();
@@ -4883,8 +4877,8 @@ impl Editor {
         let (buffer, cursor_buffer_position) =
             self.buffer.read(cx).text_anchor_for_position(cursor, cx)?;
 
-        let completion = provider.suggest(&buffer, cursor_buffer_position, cx)?;
-        let edits = completion
+        let inline_completion = provider.suggest(&buffer, cursor_buffer_position, cx)?;
+        let edits = inline_completion
             .edits
             .into_iter()
             .flat_map(|(range, new_text)| {
@@ -4909,13 +4903,12 @@ impl Editor {
 
         let mut inlay_ids = Vec::new();
         let invalidation_row_range;
-        let completion;
-        if cursor_row < edit_start_row {
+        let completion = if cursor_row < edit_start_row {
             invalidation_row_range = cursor_row..edit_end_row;
-            completion = InlineCompletion::Move(first_edit_start);
+            InlineCompletion::Move(first_edit_start)
         } else if cursor_row > edit_end_row {
             invalidation_row_range = edit_start_row..cursor_row;
-            completion = InlineCompletion::Move(first_edit_start);
+            InlineCompletion::Move(first_edit_start)
         } else {
             if edits
                 .iter()
@@ -4960,10 +4953,14 @@ impl Editor {
                 EditDisplayMode::DiffPopover
             };
 
-            completion = InlineCompletion::Edit {
+            let snapshot = multibuffer.buffer_for_excerpt(excerpt_id).cloned()?;
+
+            InlineCompletion::Edit {
                 edits,
+                edit_preview: inline_completion.edit_preview,
                 display_mode,
-            };
+                snapshot,
+            }
         };
 
         let invalidation_range = multibuffer
@@ -5006,19 +5003,26 @@ impl Editor {
             let text = match &self.active_inline_completion.as_ref()?.completion {
                 InlineCompletion::Edit {
                     edits,
+                    edit_preview,
                     display_mode: _,
-                } => inline_completion_edit_text(&editor_snapshot, edits, true, cx),
+                    snapshot,
+                } => edit_preview
+                    .as_ref()
+                    .and_then(|edit_preview| {
+                        inline_completion_edit_text(&snapshot, &edits, edit_preview, true, cx)
+                    })
+                    .map(InlineCompletionText::Edit),
                 InlineCompletion::Move(target) => {
                     let target_point =
                         target.to_point(&editor_snapshot.display_snapshot.buffer_snapshot);
                     let target_line = target_point.row + 1;
-                    InlineCompletionText::Move(
+                    Some(InlineCompletionText::Move(
                         format!("Jump to edit in line {}", target_line).into(),
-                    )
+                    ))
                 }
             };
 
-            Some(InlineCompletionMenuHint::Loaded { text })
+            Some(InlineCompletionMenuHint::Loaded { text: text? })
         } else if provider.is_refreshing(cx) {
             Some(InlineCompletionMenuHint::Loading)
         } else if provider.needs_terms_acceptance(cx) {
@@ -14960,74 +14964,23 @@ pub fn diagnostic_block_renderer(
 }
 
 fn inline_completion_edit_text(
-    editor_snapshot: &EditorSnapshot,
-    edits: &Vec<(Range<Anchor>, String)>,
+    current_snapshot: &BufferSnapshot,
+    edits: &[(Range<Anchor>, String)],
+    edit_preview: &EditPreview,
     include_deletions: bool,
     cx: &WindowContext,
-) -> InlineCompletionText {
-    let edit_start = edits
-        .first()
-        .unwrap()
-        .0
-        .start
-        .to_display_point(editor_snapshot);
-
-    let mut text = String::new();
-    let mut offset = DisplayPoint::new(edit_start.row(), 0).to_offset(editor_snapshot, Bias::Left);
-    let mut highlights = Vec::new();
-    for (old_range, new_text) in edits {
-        let old_offset_range = old_range.to_offset(&editor_snapshot.buffer_snapshot);
-        text.extend(
-            editor_snapshot
-                .buffer_snapshot
-                .chunks(offset..old_offset_range.start, false)
-                .map(|chunk| chunk.text),
-        );
-        offset = old_offset_range.end;
-
-        let start = text.len();
-        let color = if include_deletions && new_text.is_empty() {
-            text.extend(
-                editor_snapshot
-                    .buffer_snapshot
-                    .chunks(old_offset_range.start..offset, false)
-                    .map(|chunk| chunk.text),
-            );
-            cx.theme().status().deleted_background
-        } else {
-            text.push_str(new_text);
-            cx.theme().status().created_background
-        };
-        let end = text.len();
-
-        highlights.push((
-            start..end,
-            HighlightStyle {
-                background_color: Some(color),
-                ..Default::default()
-            },
-        ));
-    }
-
-    let edit_end = edits
-        .last()
-        .unwrap()
-        .0
-        .end
-        .to_display_point(editor_snapshot);
-    let end_of_line = DisplayPoint::new(edit_end.row(), editor_snapshot.line_len(edit_end.row()))
-        .to_offset(editor_snapshot, Bias::Right);
-    text.extend(
-        editor_snapshot
-            .buffer_snapshot
-            .chunks(offset..end_of_line, false)
-            .map(|chunk| chunk.text),
-    );
+) -> Option<HighlightedEdits> {
+    let edits = edits
+        .iter()
+        .map(|(anchor, text)| {
+            (
+                anchor.start.text_anchor..anchor.end.text_anchor,
+                text.clone(),
+            )
+        })
+        .collect::<Vec<_>>();
 
-    InlineCompletionText::Edit {
-        text: text.into(),
-        highlights,
-    }
+    Some(edit_preview.highlight_edits(current_snapshot, &edits, include_deletions, cx))
 }
 
 pub fn highlight_diagnostic_message(