Show progress as the agent locates which range it needs to edit (#31582)

Release Notes:

- Improved latency when the agent starts streaming edits.

---------

Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>

Cargo.lock

@@ -658,9 +658,9 @@ name = "assistant_tools"
 version = "0.1.0"
 dependencies = [
  "agent_settings",
- "aho-corasick",
  "anyhow",
  "assistant_tool",
+ "async-watch",
  "buffer_diff",
  "chrono",
  "client",

crates/agent/src/thread.rs

@@ -3414,8 +3414,8 @@ fn main() {{
         });
 
         cx.run_until_parked();
-        fake_model.stream_last_completion_response("Brief".into());
-        fake_model.stream_last_completion_response(" Introduction".into());
+        fake_model.stream_last_completion_response("Brief");
+        fake_model.stream_last_completion_response(" Introduction");
         fake_model.end_last_completion_stream();
         cx.run_until_parked();
 
@@ -3508,7 +3508,7 @@ fn main() {{
         });
 
         cx.run_until_parked();
-        fake_model.stream_last_completion_response("A successful summary".into());
+        fake_model.stream_last_completion_response("A successful summary");
         fake_model.end_last_completion_stream();
         cx.run_until_parked();
 
@@ -3550,7 +3550,7 @@ fn main() {{
 
     fn simulate_successful_response(fake_model: &FakeLanguageModel, cx: &mut TestAppContext) {
         cx.run_until_parked();
-        fake_model.stream_last_completion_response("Assistant response".into());
+        fake_model.stream_last_completion_response("Assistant response");
         fake_model.end_last_completion_stream();
         cx.run_until_parked();
     }

crates/assistant_context_editor/src/context/context_tests.rs

@@ -1210,8 +1210,8 @@ async fn test_summarization(cx: &mut TestAppContext) {
     });
 
     cx.run_until_parked();
-    fake_model.stream_last_completion_response("Brief".into());
-    fake_model.stream_last_completion_response(" Introduction".into());
+    fake_model.stream_last_completion_response("Brief");
+    fake_model.stream_last_completion_response(" Introduction");
     fake_model.end_last_completion_stream();
     cx.run_until_parked();
 
@@ -1274,7 +1274,7 @@ async fn test_thread_summary_error_retry(cx: &mut TestAppContext) {
     });
 
     cx.run_until_parked();
-    fake_model.stream_last_completion_response("A successful summary".into());
+    fake_model.stream_last_completion_response("A successful summary");
     fake_model.end_last_completion_stream();
     cx.run_until_parked();
 
@@ -1356,7 +1356,7 @@ fn setup_context_editor_with_fake_model(
 
 fn simulate_successful_response(fake_model: &FakeLanguageModel, cx: &mut TestAppContext) {
     cx.run_until_parked();
-    fake_model.stream_last_completion_response("Assistant response".into());
+    fake_model.stream_last_completion_response("Assistant response");
     fake_model.end_last_completion_stream();
     cx.run_until_parked();
 }

crates/assistant_tools/Cargo.toml

@@ -16,9 +16,9 @@ eval = []
 
 [dependencies]
 agent_settings.workspace = true
-aho-corasick.workspace = true
 anyhow.workspace = true
 assistant_tool.workspace = true
+async-watch.workspace = true
 buffer_diff.workspace = true
 chrono.workspace = true
 collections.workspace = true

crates/assistant_tools/src/edit_agent/edit_parser.rs

@@ -11,7 +11,7 @@ const END_TAGS: [&str; 3] = [OLD_TEXT_END_TAG, NEW_TEXT_END_TAG, EDITS_END_TAG];
 
 #[derive(Debug)]
 pub enum EditParserEvent {
-    OldText(String),
+    OldTextChunk { chunk: String, done: bool },
     NewTextChunk { chunk: String, done: bool },
 }
 
@@ -33,7 +33,7 @@ pub struct EditParser {
 #[derive(Debug, PartialEq)]
 enum EditParserState {
     Pending,
-    WithinOldText,
+    WithinOldText { start: bool },
     AfterOldText,
     WithinNewText { start: bool },
 }
@@ -56,20 +56,23 @@ impl EditParser {
                 EditParserState::Pending => {
                     if let Some(start) = self.buffer.find("<old_text>") {
                         self.buffer.drain(..start + "<old_text>".len());
-                        self.state = EditParserState::WithinOldText;
+                        self.state = EditParserState::WithinOldText { start: true };
                     } else {
                         break;
                     }
                 }
-                EditParserState::WithinOldText => {
-                    if let Some(tag_range) = self.find_end_tag() {
-                        let mut start = 0;
-                        if self.buffer.starts_with('\n') {
-                            start = 1;
+                EditParserState::WithinOldText { start } => {
+                    if !self.buffer.is_empty() {
+                        if *start && self.buffer.starts_with('\n') {
+                            self.buffer.remove(0);
                         }
-                        let mut old_text = self.buffer[start..tag_range.start].to_string();
-                        if old_text.ends_with('\n') {
-                            old_text.pop();
+                        *start = false;
+                    }
+
+                    if let Some(tag_range) = self.find_end_tag() {
+                        let mut chunk = self.buffer[..tag_range.start].to_string();
+                        if chunk.ends_with('\n') {
+                            chunk.pop();
                         }
 
                         self.metrics.tags += 1;
@@ -79,8 +82,14 @@ impl EditParser {
 
                         self.buffer.drain(..tag_range.end);
                         self.state = EditParserState::AfterOldText;
-                        edit_events.push(EditParserEvent::OldText(old_text));
+                        edit_events.push(EditParserEvent::OldTextChunk { chunk, done: true });
                     } else {
+                        if !self.ends_with_tag_prefix() {
+                            edit_events.push(EditParserEvent::OldTextChunk {
+                                chunk: mem::take(&mut self.buffer),
+                                done: false,
+                            });
+                        }
                         break;
                     }
                 }
@@ -115,11 +124,7 @@ impl EditParser {
                         self.state = EditParserState::Pending;
                         edit_events.push(EditParserEvent::NewTextChunk { chunk, done: true });
                     } else {
-                        let mut end_prefixes = END_TAGS
-                            .iter()
-                            .flat_map(|tag| (1..tag.len()).map(move |i| &tag[..i]))
-                            .chain(["\n"]);
-                        if end_prefixes.all(|prefix| !self.buffer.ends_with(&prefix)) {
+                        if !self.ends_with_tag_prefix() {
                             edit_events.push(EditParserEvent::NewTextChunk {
                                 chunk: mem::take(&mut self.buffer),
                                 done: false,
@@ -141,6 +146,14 @@ impl EditParser {
         Some(start_ix..start_ix + tag.len())
     }
 
+    fn ends_with_tag_prefix(&self) -> bool {
+        let mut end_prefixes = END_TAGS
+            .iter()
+            .flat_map(|tag| (1..tag.len()).map(move |i| &tag[..i]))
+            .chain(["\n"]);
+        end_prefixes.any(|prefix| self.buffer.ends_with(&prefix))
+    }
+
     pub fn finish(self) -> EditParserMetrics {
         self.metrics
     }
@@ -412,20 +425,28 @@ mod tests {
         chunk_indices.sort();
         chunk_indices.push(input.len());
 
+        let mut old_text = Some(String::new());
+        let mut new_text = None;
         let mut pending_edit = Edit::default();
         let mut edits = Vec::new();
         let mut last_ix = 0;
         for chunk_ix in chunk_indices {
             for event in parser.push(&input[last_ix..chunk_ix]) {
                 match event {
-                    EditParserEvent::OldText(old_text) => {
-                        pending_edit.old_text = old_text;
+                    EditParserEvent::OldTextChunk { chunk, done } => {
+                        old_text.as_mut().unwrap().push_str(&chunk);
+                        if done {
+                            pending_edit.old_text = old_text.take().unwrap();
+                            new_text = Some(String::new());
+                        }
                     }
                     EditParserEvent::NewTextChunk { chunk, done } => {
-                        pending_edit.new_text.push_str(&chunk);
+                        new_text.as_mut().unwrap().push_str(&chunk);
                         if done {
+                            pending_edit.new_text = new_text.take().unwrap();
                             edits.push(pending_edit);
                             pending_edit = Edit::default();
+                            old_text = Some(String::new());
                         }
                     }
                 }
@@ -433,8 +454,6 @@ mod tests {
             last_ix = chunk_ix;
         }
 
-        assert_eq!(pending_edit, Edit::default(), "unfinished edit");
-
         edits
     }
 }

crates/assistant_tools/src/edit_agent/streaming_fuzzy_matcher.rs

@@ -0,0 +1,694 @@
+use language::{Point, TextBufferSnapshot};
+use std::{cmp, ops::Range};
+
+const REPLACEMENT_COST: u32 = 1;
+const INSERTION_COST: u32 = 3;
+const DELETION_COST: u32 = 10;
+
+/// A streaming fuzzy matcher that can process text chunks incrementally
+/// and return the best match found so far at each step.
+pub struct StreamingFuzzyMatcher {
+    snapshot: TextBufferSnapshot,
+    query_lines: Vec<String>,
+    incomplete_line: String,
+    best_match: Option<Range<usize>>,
+    matrix: SearchMatrix,
+}
+
+impl StreamingFuzzyMatcher {
+    pub fn new(snapshot: TextBufferSnapshot) -> Self {
+        let buffer_line_count = snapshot.max_point().row as usize + 1;
+        Self {
+            snapshot,
+            query_lines: Vec::new(),
+            incomplete_line: String::new(),
+            best_match: None,
+            matrix: SearchMatrix::new(buffer_line_count + 1),
+        }
+    }
+
+    /// Returns the query lines.
+    pub fn query_lines(&self) -> &[String] {
+        &self.query_lines
+    }
+
+    /// Push a new chunk of text and get the best match found so far.
+    ///
+    /// This method accumulates text chunks and processes complete lines.
+    /// Partial lines are buffered internally until a newline is received.
+    ///
+    /// # Returns
+    ///
+    /// Returns `Some(range)` if a match has been found with the accumulated
+    /// query so far, or `None` if no suitable match exists yet.
+    pub fn push(&mut self, chunk: &str) -> Option<Range<usize>> {
+        // Add the chunk to our incomplete line buffer
+        self.incomplete_line.push_str(chunk);
+
+        if let Some((last_pos, _)) = self.incomplete_line.match_indices('\n').next_back() {
+            let complete_part = &self.incomplete_line[..=last_pos];
+
+            // Split into lines and add to query_lines
+            for line in complete_part.lines() {
+                self.query_lines.push(line.to_string());
+            }
+
+            self.incomplete_line.replace_range(..last_pos + 1, "");
+
+            self.best_match = self.resolve_location_fuzzy();
+        }
+
+        self.best_match.clone()
+    }
+
+    /// Finish processing and return the final best match.
+    ///
+    /// This processes any remaining incomplete line before returning the final
+    /// match result.
+    pub fn finish(&mut self) -> Option<Range<usize>> {
+        // Process any remaining incomplete line
+        if !self.incomplete_line.is_empty() {
+            self.query_lines.push(self.incomplete_line.clone());
+            self.best_match = self.resolve_location_fuzzy();
+        }
+
+        self.best_match.clone()
+    }
+
+    fn resolve_location_fuzzy(&mut self) -> Option<Range<usize>> {
+        let new_query_line_count = self.query_lines.len();
+        let old_query_line_count = self.matrix.rows.saturating_sub(1);
+        if new_query_line_count == old_query_line_count {
+            return None;
+        }
+
+        self.matrix.resize_rows(new_query_line_count + 1);
+
+        // Process only the new query lines
+        for row in old_query_line_count..new_query_line_count {
+            let query_line = self.query_lines[row].trim();
+            let leading_deletion_cost = (row + 1) as u32 * DELETION_COST;
+
+            self.matrix.set(
+                row + 1,
+                0,
+                SearchState::new(leading_deletion_cost, SearchDirection::Up),
+            );
+
+            let mut buffer_lines = self.snapshot.as_rope().chunks().lines();
+            let mut col = 0;
+            while let Some(buffer_line) = buffer_lines.next() {
+                let buffer_line = buffer_line.trim();
+                let up = SearchState::new(
+                    self.matrix
+                        .get(row, col + 1)
+                        .cost
+                        .saturating_add(DELETION_COST),
+                    SearchDirection::Up,
+                );
+                let left = SearchState::new(
+                    self.matrix
+                        .get(row + 1, col)
+                        .cost
+                        .saturating_add(INSERTION_COST),
+                    SearchDirection::Left,
+                );
+                let diagonal = SearchState::new(
+                    if query_line == buffer_line {
+                        self.matrix.get(row, col).cost
+                    } else if fuzzy_eq(query_line, buffer_line) {
+                        self.matrix.get(row, col).cost + REPLACEMENT_COST
+                    } else {
+                        self.matrix
+                            .get(row, col)
+                            .cost
+                            .saturating_add(DELETION_COST + INSERTION_COST)
+                    },
+                    SearchDirection::Diagonal,
+                );
+                self.matrix
+                    .set(row + 1, col + 1, up.min(left).min(diagonal));
+                col += 1;
+            }
+        }
+
+        // Traceback to find the best match
+        let buffer_line_count = self.snapshot.max_point().row as usize + 1;
+        let mut buffer_row_end = buffer_line_count as u32;
+        let mut best_cost = u32::MAX;
+        for col in 1..=buffer_line_count {
+            let cost = self.matrix.get(new_query_line_count, col).cost;
+            if cost < best_cost {
+                best_cost = cost;
+                buffer_row_end = col as u32;
+            }
+        }
+
+        let mut matched_lines = 0;
+        let mut query_row = new_query_line_count;
+        let mut buffer_row_start = buffer_row_end;
+        while query_row > 0 && buffer_row_start > 0 {
+            let current = self.matrix.get(query_row, buffer_row_start as usize);
+            match current.direction {
+                SearchDirection::Diagonal => {
+                    query_row -= 1;
+                    buffer_row_start -= 1;
+                    matched_lines += 1;
+                }
+                SearchDirection::Up => {
+                    query_row -= 1;
+                }
+                SearchDirection::Left => {
+                    buffer_row_start -= 1;
+                }
+            }
+        }
+
+        let matched_buffer_row_count = buffer_row_end - buffer_row_start;
+        let matched_ratio = matched_lines as f32
+            / (matched_buffer_row_count as f32).max(new_query_line_count as f32);
+        if matched_ratio >= 0.8 {
+            let buffer_start_ix = self
+                .snapshot
+                .point_to_offset(Point::new(buffer_row_start, 0));
+            let buffer_end_ix = self.snapshot.point_to_offset(Point::new(
+                buffer_row_end - 1,
+                self.snapshot.line_len(buffer_row_end - 1),
+            ));
+            Some(buffer_start_ix..buffer_end_ix)
+        } else {
+            None
+        }
+    }
+}
+
+fn fuzzy_eq(left: &str, right: &str) -> bool {
+    const THRESHOLD: f64 = 0.8;
+
+    let min_levenshtein = left.len().abs_diff(right.len());
+    let min_normalized_levenshtein =
+        1. - (min_levenshtein as f64 / cmp::max(left.len(), right.len()) as f64);
+    if min_normalized_levenshtein < THRESHOLD {
+        return false;
+    }
+
+    strsim::normalized_levenshtein(left, right) >= THRESHOLD
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
+enum SearchDirection {
+    Up,
+    Left,
+    Diagonal,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+struct SearchState {
+    cost: u32,
+    direction: SearchDirection,
+}
+
+impl SearchState {
+    fn new(cost: u32, direction: SearchDirection) -> Self {
+        Self { cost, direction }
+    }
+}
+
+struct SearchMatrix {
+    cols: usize,
+    rows: usize,
+    data: Vec<SearchState>,
+}
+
+impl SearchMatrix {
+    fn new(cols: usize) -> Self {
+        SearchMatrix {
+            cols,
+            rows: 0,
+            data: Vec::new(),
+        }
+    }
+
+    fn resize_rows(&mut self, needed_rows: usize) {
+        debug_assert!(needed_rows > self.rows);
+        self.rows = needed_rows;
+        self.data.resize(
+            self.rows * self.cols,
+            SearchState::new(0, SearchDirection::Diagonal),
+        );
+    }
+
+    fn get(&self, row: usize, col: usize) -> SearchState {
+        debug_assert!(row < self.rows && col < self.cols);
+        self.data[row * self.cols + col]
+    }
+
+    fn set(&mut self, row: usize, col: usize, state: SearchState) {
+        debug_assert!(row < self.rows && col < self.cols);
+        self.data[row * self.cols + col] = state;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use indoc::indoc;
+    use language::{BufferId, TextBuffer};
+    use rand::prelude::*;
+    use util::test::{generate_marked_text, marked_text_ranges};
+
+    #[test]
+    fn test_empty_query() {
+        let buffer = TextBuffer::new(
+            0,
+            BufferId::new(1).unwrap(),
+            "Hello world\nThis is a test\nFoo bar baz",
+        );
+        let snapshot = buffer.snapshot();
+
+        let mut finder = StreamingFuzzyMatcher::new(snapshot.clone());
+        assert_eq!(push(&mut finder, ""), None);
+        assert_eq!(finish(finder), None);
+    }
+
+    #[test]
+    fn test_streaming_exact_match() {
+        let buffer = TextBuffer::new(
+            0,
+            BufferId::new(1).unwrap(),
+            "Hello world\nThis is a test\nFoo bar baz",
+        );
+        let snapshot = buffer.snapshot();
+
+        let mut finder = StreamingFuzzyMatcher::new(snapshot.clone());
+
+        // Push partial query
+        assert_eq!(push(&mut finder, "This"), None);
+
+        // Complete the line
+        assert_eq!(
+            push(&mut finder, " is a test\n"),
+            Some("This is a test".to_string())
+        );
+
+        // Finish should return the same result
+        assert_eq!(finish(finder), Some("This is a test".to_string()));
+    }
+
+    #[test]
+    fn test_streaming_fuzzy_match() {
+        let buffer = TextBuffer::new(
+            0,
+            BufferId::new(1).unwrap(),
+            indoc! {"
+                function foo(a, b) {
+                    return a + b;
+                }
+
+                function bar(x, y) {
+                    return x * y;
+                }
+            "},
+        );
+        let snapshot = buffer.snapshot();
+
+        let mut finder = StreamingFuzzyMatcher::new(snapshot.clone());
+
+        // Push a fuzzy query that should match the first function
+        assert_eq!(
+            push(&mut finder, "function foo(a, c) {\n").as_deref(),
+            Some("function foo(a, b) {")
+        );
+        assert_eq!(
+            push(&mut finder, "    return a + c;\n}\n").as_deref(),
+            Some(concat!(
+                "function foo(a, b) {\n",
+                "    return a + b;\n",
+                "}"
+            ))
+        );
+    }
+
+    #[test]
+    fn test_incremental_improvement() {
+        let buffer = TextBuffer::new(
+            0,
+            BufferId::new(1).unwrap(),
+            "Line 1\nLine 2\nLine 3\nLine 4\nLine 5",
+        );
+        let snapshot = buffer.snapshot();
+
+        let mut finder = StreamingFuzzyMatcher::new(snapshot.clone());
+
+        // No match initially
+        assert_eq!(push(&mut finder, "Lin"), None);
+
+        // Get a match when we complete a line
+        assert_eq!(push(&mut finder, "e 3\n"), Some("Line 3".to_string()));
+
+        // The match might change if we add more specific content
+        assert_eq!(
+            push(&mut finder, "Line 4\n"),
+            Some("Line 3\nLine 4".to_string())
+        );
+        assert_eq!(finish(finder), Some("Line 3\nLine 4".to_string()));
+    }
+
+    #[test]
+    fn test_incomplete_lines_buffering() {
+        let buffer = TextBuffer::new(
+            0,
+            BufferId::new(1).unwrap(),
+            indoc! {"
+                The quick brown fox
+                jumps over the lazy dog
+                Pack my box with five dozen liquor jugs
+            "},
+        );
+        let snapshot = buffer.snapshot();
+
+        let mut finder = StreamingFuzzyMatcher::new(snapshot.clone());
+
+        // Push text in small chunks across line boundaries
+        assert_eq!(push(&mut finder, "jumps "), None); // No newline yet
+        assert_eq!(push(&mut finder, "over the"), None); // Still no newline
+        assert_eq!(push(&mut finder, " lazy"), None); // Still incomplete
+
+        // Complete the line
+        assert_eq!(
+            push(&mut finder, " dog\n"),
+            Some("jumps over the lazy dog".to_string())
+        );
+    }
+
+    #[test]
+    fn test_multiline_fuzzy_match() {
+        let buffer = TextBuffer::new(
+            0,
+            BufferId::new(1).unwrap(),
+            indoc! {r#"
+                impl Display for User {
+                    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+                        write!(f, "User: {} ({})", self.name, self.email)
+                    }
+                }
+
+                impl Debug for User {
+                    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+                        f.debug_struct("User")
+                            .field("name", &self.name)
+                            .field("email", &self.email)
+                            .finish()
+                    }
+                }
+            "#},
+        );
+        let snapshot = buffer.snapshot();
+
+        let mut finder = StreamingFuzzyMatcher::new(snapshot.clone());
+
+        assert_eq!(
+            push(&mut finder, "impl Debug for User {\n"),
+            Some("impl Debug for User {".to_string())
+        );
+        assert_eq!(
+            push(
+                &mut finder,
+                "    fn fmt(&self, f: &mut Formatter) -> Result {\n"
+            )
+            .as_deref(),
+            Some(concat!(
+                "impl Debug for User {\n",
+                "    fn fmt(&self, f: &mut Formatter) -> fmt::Result {"
+            ))
+        );
+        assert_eq!(
+            push(&mut finder, "        f.debug_struct(\"User\")\n").as_deref(),
+            Some(concat!(
+                "impl Debug for User {\n",
+                "    fn fmt(&self, f: &mut Formatter) -> fmt::Result {\n",
+                "        f.debug_struct(\"User\")"
+            ))
+        );
+        assert_eq!(
+            push(
+                &mut finder,
+                "            .field(\"name\", &self.username)\n"
+            )
+            .as_deref(),
+            Some(concat!(
+                "impl Debug for User {\n",
+                "    fn fmt(&self, f: &mut Formatter) -> fmt::Result {\n",
+                "        f.debug_struct(\"User\")\n",
+                "            .field(\"name\", &self.name)"
+            ))
+        );
+        assert_eq!(
+            finish(finder).as_deref(),
+            Some(concat!(
+                "impl Debug for User {\n",
+                "    fn fmt(&self, f: &mut Formatter) -> fmt::Result {\n",
+                "        f.debug_struct(\"User\")\n",
+                "            .field(\"name\", &self.name)"
+            ))
+        );
+    }
+
+    #[gpui::test(iterations = 100)]
+    fn test_resolve_location_single_line(mut rng: StdRng) {
+        assert_location_resolution(
+            concat!(
+                "    Lorem\n",
+                "«    ipsum»\n",
+                "    dolor sit amet\n",
+                "    consecteur",
+            ),
+            "ipsum",
+            &mut rng,
+        );
+    }
+
+    #[gpui::test(iterations = 100)]
+    fn test_resolve_location_multiline(mut rng: StdRng) {
+        assert_location_resolution(
+            concat!(
+                "    Lorem\n",
+                "«    ipsum\n",
+                "    dolor sit amet»\n",
+                "    consecteur",
+            ),
+            "ipsum\ndolor sit amet",
+            &mut rng,
+        );
+    }
+
+    #[gpui::test(iterations = 100)]
+    fn test_resolve_location_function_with_typo(mut rng: StdRng) {
+        assert_location_resolution(
+            indoc! {"
+                «fn foo1(a: usize) -> usize {
+                    40
+                }»
+
+                fn foo2(b: usize) -> usize {
+                    42
+                }
+            "},
+            "fn foo1(a: usize) -> u32 {\n40\n}",
+            &mut rng,
+        );
+    }
+
+    #[gpui::test(iterations = 100)]
+    fn test_resolve_location_class_methods(mut rng: StdRng) {
+        assert_location_resolution(
+            indoc! {"
+                class Something {
+                    one() { return 1; }
+                «    two() { return 2222; }
+                    three() { return 333; }
+                    four() { return 4444; }
+                    five() { return 5555; }
+                    six() { return 6666; }»
+                    seven() { return 7; }
+                    eight() { return 8; }
+                }
+            "},
+            indoc! {"
+                two() { return 2222; }
+                four() { return 4444; }
+                five() { return 5555; }
+                six() { return 6666; }
+            "},
+            &mut rng,
+        );
+    }
+
+    #[gpui::test(iterations = 100)]
+    fn test_resolve_location_imports_no_match(mut rng: StdRng) {
+        assert_location_resolution(
+            indoc! {"
+                use std::ops::Range;
+                use std::sync::Mutex;
+                use std::{
+                    collections::HashMap,
+                    env,
+                    ffi::{OsStr, OsString},
+                    fs,
+                    io::{BufRead, BufReader},
+                    mem,
+                    path::{Path, PathBuf},
+                    process::Command,
+                    sync::LazyLock,
+                    time::SystemTime,
+                };
+            "},
+            indoc! {"
+                use std::collections::{HashMap, HashSet};
+                use std::ffi::{OsStr, OsString};
+                use std::fmt::Write as _;
+                use std::fs;
+                use std::io::{BufReader, Read, Write};
+                use std::mem;
+                use std::path::{Path, PathBuf};
+                use std::process::Command;
+                use std::sync::Arc;
+            "},
+            &mut rng,
+        );
+    }
+
+    #[gpui::test(iterations = 100)]
+    fn test_resolve_location_nested_closure(mut rng: StdRng) {
+        assert_location_resolution(
+            indoc! {"
+                impl Foo {
+                    fn new() -> Self {
+                        Self {
+                            subscriptions: vec![
+                                cx.observe_window_activation(window, |editor, window, cx| {
+                                    let active = window.is_window_active();
+                                    editor.blink_manager.update(cx, |blink_manager, cx| {
+                                        if active {
+                                            blink_manager.enable(cx);
+                                        } else {
+                                            blink_manager.disable(cx);
+                                        }
+                                    });
+                                }),
+                            ];
+                        }
+                    }
+                }
+            "},
+            concat!(
+                "                    editor.blink_manager.update(cx, |blink_manager, cx| {\n",
+                "                        blink_manager.enable(cx);\n",
+                "                    });",
+            ),
+            &mut rng,
+        );
+    }
+
+    #[gpui::test(iterations = 100)]
+    fn test_resolve_location_tool_invocation(mut rng: StdRng) {
+        assert_location_resolution(
+            indoc! {r#"
+                let tool = cx
+                    .update(|cx| working_set.tool(&tool_name, cx))
+                    .map_err(|err| {
+                        anyhow!("Failed to look up tool '{}': {}", tool_name, err)
+                    })?;
+
+                let Some(tool) = tool else {
+                    return Err(anyhow!("Tool '{}' not found", tool_name));
+                };
+
+                let project = project.clone();
+                let action_log = action_log.clone();
+                let messages = messages.clone();
+                let tool_result = cx
+                    .update(|cx| tool.run(invocation.input, &messages, project, action_log, cx))
+                    .map_err(|err| anyhow!("Failed to start tool '{}': {}", tool_name, err))?;
+
+                tasks.push(tool_result.output);
+            "#},
+            concat!(
+                "let tool_result = cx\n",
+                "    .update(|cx| tool.run(invocation.input, &messages, project, action_log, cx))\n",
+                "    .output;",
+            ),
+            &mut rng,
+        );
+    }
+
+    #[track_caller]
+    fn assert_location_resolution(text_with_expected_range: &str, query: &str, rng: &mut StdRng) {
+        let (text, expected_ranges) = marked_text_ranges(text_with_expected_range, false);
+        let buffer = TextBuffer::new(0, BufferId::new(1).unwrap(), text.clone());
+        let snapshot = buffer.snapshot();
+
+        let mut matcher = StreamingFuzzyMatcher::new(snapshot.clone());
+
+        // Split query into random chunks
+        let chunks = to_random_chunks(rng, query);
+
+        // Push chunks incrementally
+        for chunk in &chunks {
+            matcher.push(chunk);
+        }
+
+        let result = matcher.finish();
+
+        // If no expected ranges, we expect no match
+        if expected_ranges.is_empty() {
+            assert_eq!(
+                result, None,
+                "Expected no match for query: {:?}, but found: {:?}",
+                query, result
+            );
+        } else {
+            let mut actual_ranges = Vec::new();
+            if let Some(range) = result {
+                actual_ranges.push(range);
+            }
+
+            let text_with_actual_range = generate_marked_text(&text, &actual_ranges, false);
+            pretty_assertions::assert_eq!(
+                text_with_actual_range,
+                text_with_expected_range,
+                "Query: {:?}, Chunks: {:?}",
+                query,
+                chunks
+            );
+        }
+    }
+
+    fn to_random_chunks(rng: &mut StdRng, input: &str) -> Vec<String> {
+        let chunk_count = rng.gen_range(1..=cmp::min(input.len(), 50));
+        let mut chunk_indices = (0..input.len()).choose_multiple(rng, chunk_count);
+        chunk_indices.sort();
+        chunk_indices.push(input.len());
+
+        let mut chunks = Vec::new();
+        let mut last_ix = 0;
+        for chunk_ix in chunk_indices {
+            chunks.push(input[last_ix..chunk_ix].to_string());
+            last_ix = chunk_ix;
+        }
+        chunks
+    }
+
+    fn push(finder: &mut StreamingFuzzyMatcher, chunk: &str) -> Option<String> {
+        finder
+            .push(chunk)
+            .map(|range| finder.snapshot.text_for_range(range).collect::<String>())
+    }
+
+    fn finish(mut finder: StreamingFuzzyMatcher) -> Option<String> {
+        let snapshot = finder.snapshot.clone();
+        finder
+            .finish()
+            .map(|range| snapshot.text_for_range(range).collect::<String>())
+    }
+}

crates/assistant_tools/src/edit_file_tool.rs

@@ -12,13 +12,13 @@ use buffer_diff::{BufferDiff, BufferDiffSnapshot};
 use editor::{Editor, EditorMode, MinimapVisibility, MultiBuffer, PathKey};
 use futures::StreamExt;
 use gpui::{
-    Animation, AnimationExt, AnyWindowHandle, App, AppContext, AsyncApp, Entity, EntityId, Task,
+    Animation, AnimationExt, AnyWindowHandle, App, AppContext, AsyncApp, Entity, Task,
     TextStyleRefinement, WeakEntity, pulsating_between,
 };
 use indoc::formatdoc;
 use language::{
-    Anchor, Buffer, Capability, LanguageRegistry, LineEnding, OffsetRangeExt, Rope, TextBuffer,
-    language_settings::SoftWrap,
+    Anchor, Buffer, Capability, LanguageRegistry, LineEnding, OffsetRangeExt, Point, Rope,
+    TextBuffer, language_settings::SoftWrap,
 };
 use language_model::{LanguageModel, LanguageModelRequest, LanguageModelToolSchemaFormat};
 use markdown::{Markdown, MarkdownElement, MarkdownStyle};
@@ -27,6 +27,8 @@ use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use settings::Settings;
 use std::{
+    cmp::Reverse,
+    ops::Range,
     path::{Path, PathBuf},
     sync::Arc,
     time::Duration,
@@ -98,7 +100,7 @@ pub enum EditFileMode {
 pub struct EditFileToolOutput {
     pub original_path: PathBuf,
     pub new_text: String,
-    pub old_text: String,
+    pub old_text: Arc<String>,
     pub raw_output: Option<EditAgentOutput>,
 }
 
@@ -200,10 +202,14 @@ impl Tool for EditFileTool {
             let old_text = cx
                 .background_spawn({
                     let old_snapshot = old_snapshot.clone();
-                    async move { old_snapshot.text() }
+                    async move { Arc::new(old_snapshot.text()) }
                 })
                 .await;
 
+            if let Some(card) = card_clone.as_ref() {
+                card.update(cx, |card, cx| card.initialize(buffer.clone(), cx))?;
+            }
+
             let (output, mut events) = if matches!(input.mode, EditFileMode::Edit) {
                 edit_agent.edit(
                     buffer.clone(),
@@ -225,26 +231,15 @@ impl Tool for EditFileTool {
                 match event {
                     EditAgentOutputEvent::Edited => {
                         if let Some(card) = card_clone.as_ref() {
-                            let new_snapshot =
-                                buffer.read_with(cx, |buffer, _cx| buffer.snapshot())?;
-                            let new_text = cx
-                                .background_spawn({
-                                    let new_snapshot = new_snapshot.clone();
-                                    async move { new_snapshot.text() }
-                                })
-                                .await;
-                            card.update(cx, |card, cx| {
-                                card.set_diff(
-                                    project_path.path.clone(),
-                                    old_text.clone(),
-                                    new_text,
-                                    cx,
-                                );
-                            })
-                            .log_err();
+                            card.update(cx, |card, cx| card.update_diff(cx))?;
+                        }
+                    }
+                    EditAgentOutputEvent::UnresolvedEditRange => hallucinated_old_text = true,
+                    EditAgentOutputEvent::ResolvingEditRange(range) => {
+                        if let Some(card) = card_clone.as_ref() {
+                            card.update(cx, |card, cx| card.reveal_range(range, cx))?;
                         }
                     }
-                    EditAgentOutputEvent::OldTextNotFound(_) => hallucinated_old_text = true,
                 }
             }
             let agent_output = output.await?;
@@ -266,13 +261,14 @@ impl Tool for EditFileTool {
             let output = EditFileToolOutput {
                 original_path: project_path.path.to_path_buf(),
                 new_text: new_text.clone(),
-                old_text: old_text.clone(),
+                old_text,
                 raw_output: Some(agent_output),
             };
 
             if let Some(card) = card_clone {
                 card.update(cx, |card, cx| {
-                    card.set_diff(project_path.path.clone(), old_text, new_text, cx);
+                    card.update_diff(cx);
+                    card.finalize(cx)
                 })
                 .log_err();
             }
@@ -282,12 +278,15 @@ impl Tool for EditFileTool {
                 anyhow::ensure!(
                     !hallucinated_old_text,
                     formatdoc! {"
-                    Some edits were produced but none of them could be applied.
-                    Read the relevant sections of {input_path} again so that
-                    I can perform the requested edits.
-                "}
+                        Some edits were produced but none of them could be applied.
+                        Read the relevant sections of {input_path} again so that
+                        I can perform the requested edits.
+                    "}
                 );
-                Ok("No edits were made.".to_string().into())
+                Ok(ToolResultOutput {
+                    content: ToolResultContent::Text("No edits were made.".into()),
+                    output: serde_json::to_value(output).ok(),
+                })
             } else {
                 Ok(ToolResultOutput {
                     content: ToolResultContent::Text(format!(
@@ -318,16 +317,48 @@ impl Tool for EditFileTool {
         };
 
         let card = cx.new(|cx| {
-            let mut card = EditFileToolCard::new(output.original_path.clone(), project, window, cx);
-            card.set_diff(
-                output.original_path.into(),
-                output.old_text,
-                output.new_text,
-                cx,
-            );
-            card
+            EditFileToolCard::new(output.original_path.clone(), project.clone(), window, cx)
         });
 
+        cx.spawn({
+            let path: Arc<Path> = output.original_path.into();
+            let language_registry = project.read(cx).languages().clone();
+            let card = card.clone();
+            async move |cx| {
+                let buffer =
+                    build_buffer(output.new_text, path.clone(), &language_registry, cx).await?;
+                let buffer_diff =
+                    build_buffer_diff(output.old_text.clone(), &buffer, &language_registry, cx)
+                        .await?;
+                card.update(cx, |card, cx| {
+                    card.multibuffer.update(cx, |multibuffer, cx| {
+                        let snapshot = buffer.read(cx).snapshot();
+                        let diff = buffer_diff.read(cx);
+                        let diff_hunk_ranges = diff
+                            .hunks_intersecting_range(Anchor::MIN..Anchor::MAX, &snapshot, cx)
+                            .map(|diff_hunk| diff_hunk.buffer_range.to_point(&snapshot))
+                            .collect::<Vec<_>>();
+
+                        multibuffer.set_excerpts_for_path(
+                            PathKey::for_buffer(&buffer, cx),
+                            buffer,
+                            diff_hunk_ranges,
+                            editor::DEFAULT_MULTIBUFFER_CONTEXT,
+                            cx,
+                        );
+                        multibuffer.add_diff(buffer_diff, cx);
+                        let end = multibuffer.len(cx);
+                        card.total_lines =
+                            Some(multibuffer.snapshot(cx).offset_to_point(end).row + 1);
+                    });
+
+                    cx.notify();
+                })?;
+                anyhow::Ok(())
+            }
+        })
+        .detach_and_log_err(cx);
+
         Some(card.into())
     }
 }
@@ -402,12 +433,15 @@ pub struct EditFileToolCard {
     editor: Entity<Editor>,
     multibuffer: Entity<MultiBuffer>,
     project: Entity<Project>,
+    buffer: Option<Entity<Buffer>>,
+    base_text: Option<Arc<String>>,
+    buffer_diff: Option<Entity<BufferDiff>>,
+    revealed_ranges: Vec<Range<Anchor>>,
     diff_task: Option<Task<Result<()>>>,
     preview_expanded: bool,
     error_expanded: Option<Entity<Markdown>>,
     full_height_expanded: bool,
     total_lines: Option<u32>,
-    editor_unique_id: EntityId,
 }
 
 impl EditFileToolCard {
@@ -442,11 +476,14 @@ impl EditFileToolCard {
             editor
         });
         Self {
-            editor_unique_id: editor.entity_id(),
             path,
             project,
             editor,
             multibuffer,
+            buffer: None,
+            base_text: None,
+            buffer_diff: None,
+            revealed_ranges: Vec::new(),
             diff_task: None,
             preview_expanded: true,
             error_expanded: None,
@@ -455,46 +492,184 @@ impl EditFileToolCard {
         }
     }
 
-    pub fn has_diff(&self) -> bool {
-        self.total_lines.is_some()
+    pub fn initialize(&mut self, buffer: Entity<Buffer>, cx: &mut App) {
+        let buffer_snapshot = buffer.read(cx).snapshot();
+        let base_text = buffer_snapshot.text();
+        let language_registry = buffer.read(cx).language_registry();
+        let text_snapshot = buffer.read(cx).text_snapshot();
+
+        // Create a buffer diff with the current text as the base
+        let buffer_diff = cx.new(|cx| {
+            let mut diff = BufferDiff::new(&text_snapshot, cx);
+            let _ = diff.set_base_text(
+                buffer_snapshot.clone(),
+                language_registry,
+                text_snapshot,
+                cx,
+            );
+            diff
+        });
+
+        self.buffer = Some(buffer.clone());
+        self.base_text = Some(base_text.into());
+        self.buffer_diff = Some(buffer_diff.clone());
+
+        // Add the diff to the multibuffer
+        self.multibuffer
+            .update(cx, |multibuffer, cx| multibuffer.add_diff(buffer_diff, cx));
     }
 
-    pub fn set_diff(
-        &mut self,
-        path: Arc<Path>,
-        old_text: String,
-        new_text: String,
-        cx: &mut Context<Self>,
-    ) {
-        let language_registry = self.project.read(cx).languages().clone();
-        self.diff_task = Some(cx.spawn(async move |this, cx| {
-            let buffer = build_buffer(new_text, path.clone(), &language_registry, cx).await?;
-            let buffer_diff = build_buffer_diff(old_text, &buffer, &language_registry, cx).await?;
+    pub fn is_loading(&self) -> bool {
+        self.total_lines.is_none()
+    }
 
+    pub fn update_diff(&mut self, cx: &mut Context<Self>) {
+        let Some(buffer) = self.buffer.as_ref() else {
+            return;
+        };
+        let Some(buffer_diff) = self.buffer_diff.as_ref() else {
+            return;
+        };
+
+        let buffer = buffer.clone();
+        let buffer_diff = buffer_diff.clone();
+        let base_text = self.base_text.clone();
+        self.diff_task = Some(cx.spawn(async move |this, cx| {
+            let text_snapshot = buffer.read_with(cx, |buffer, _| buffer.text_snapshot())?;
+            let diff_snapshot = BufferDiff::update_diff(
+                buffer_diff.clone(),
+                text_snapshot.clone(),
+                base_text,
+                false,
+                false,
+                None,
+                None,
+                cx,
+            )
+            .await?;
+            buffer_diff.update(cx, |diff, cx| {
+                diff.set_snapshot(diff_snapshot, &text_snapshot, cx)
+            })?;
+            this.update(cx, |this, cx| this.update_visible_ranges(cx))
+        }));
+    }
+
+    pub fn reveal_range(&mut self, range: Range<Anchor>, cx: &mut Context<Self>) {
+        self.revealed_ranges.push(range);
+        self.update_visible_ranges(cx);
+    }
+
+    fn update_visible_ranges(&mut self, cx: &mut Context<Self>) {
+        let Some(buffer) = self.buffer.as_ref() else {
+            return;
+        };
+
+        let ranges = self.excerpt_ranges(cx);
+        self.total_lines = self.multibuffer.update(cx, |multibuffer, cx| {
+            multibuffer.set_excerpts_for_path(
+                PathKey::for_buffer(buffer, cx),
+                buffer.clone(),
+                ranges,
+                editor::DEFAULT_MULTIBUFFER_CONTEXT,
+                cx,
+            );
+            let end = multibuffer.len(cx);
+            Some(multibuffer.snapshot(cx).offset_to_point(end).row + 1)
+        });
+        cx.notify();
+    }
+
+    fn excerpt_ranges(&self, cx: &App) -> Vec<Range<Point>> {
+        let Some(buffer) = self.buffer.as_ref() else {
+            return Vec::new();
+        };
+        let Some(diff) = self.buffer_diff.as_ref() else {
+            return Vec::new();
+        };
+
+        let buffer = buffer.read(cx);
+        let diff = diff.read(cx);
+        let mut ranges = diff
+            .hunks_intersecting_range(Anchor::MIN..Anchor::MAX, &buffer, cx)
+            .map(|diff_hunk| diff_hunk.buffer_range.to_point(&buffer))
+            .collect::<Vec<_>>();
+        ranges.extend(
+            self.revealed_ranges
+                .iter()
+                .map(|range| range.to_point(&buffer)),
+        );
+        ranges.sort_unstable_by_key(|range| (range.start, Reverse(range.end)));
+
+        // Merge adjacent ranges
+        let mut ranges = ranges.into_iter().peekable();
+        let mut merged_ranges = Vec::new();
+        while let Some(mut range) = ranges.next() {
+            while let Some(next_range) = ranges.peek() {
+                if range.end >= next_range.start {
+                    range.end = range.end.max(next_range.end);
+                    ranges.next();
+                } else {
+                    break;
+                }
+            }
+
+            merged_ranges.push(range);
+        }
+        merged_ranges
+    }
+
+    pub fn finalize(&mut self, cx: &mut Context<Self>) -> Result<()> {
+        let ranges = self.excerpt_ranges(cx);
+        let buffer = self.buffer.take().context("card was already finalized")?;
+        let base_text = self
+            .base_text
+            .take()
+            .context("card was already finalized")?;
+        let language_registry = self.project.read(cx).languages().clone();
+
+        // Replace the buffer in the multibuffer with the snapshot
+        let buffer = cx.new(|cx| {
+            let language = buffer.read(cx).language().cloned();
+            let buffer = TextBuffer::new_normalized(
+                0,
+                cx.entity_id().as_non_zero_u64().into(),
+                buffer.read(cx).line_ending(),
+                buffer.read(cx).as_rope().clone(),
+            );
+            let mut buffer = Buffer::build(buffer, None, Capability::ReadWrite);
+            buffer.set_language(language, cx);
+            buffer
+        });
+
+        let buffer_diff = cx.spawn({
+            let buffer = buffer.clone();
+            let language_registry = language_registry.clone();
+            async move |_this, cx| {
+                build_buffer_diff(base_text, &buffer, &language_registry, cx).await
+            }
+        });
+
+        cx.spawn(async move |this, cx| {
+            let buffer_diff = buffer_diff.await?;
             this.update(cx, |this, cx| {
-                this.total_lines = this.multibuffer.update(cx, |multibuffer, cx| {
-                    let snapshot = buffer.read(cx).snapshot();
-                    let diff = buffer_diff.read(cx);
-                    let diff_hunk_ranges = diff
-                        .hunks_intersecting_range(Anchor::MIN..Anchor::MAX, &snapshot, cx)
-                        .map(|diff_hunk| diff_hunk.buffer_range.to_point(&snapshot))
-                        .collect::<Vec<_>>();
+                this.multibuffer.update(cx, |multibuffer, cx| {
+                    let path_key = PathKey::for_buffer(&buffer, cx);
                     multibuffer.clear(cx);
                     multibuffer.set_excerpts_for_path(
-                        PathKey::for_buffer(&buffer, cx),
+                        path_key,
                         buffer,
-                        diff_hunk_ranges,
+                        ranges,
                         editor::DEFAULT_MULTIBUFFER_CONTEXT,
                         cx,
                     );
-                    multibuffer.add_diff(buffer_diff, cx);
-                    let end = multibuffer.len(cx);
-                    Some(multibuffer.snapshot(cx).offset_to_point(end).row + 1)
+                    multibuffer.add_diff(buffer_diff.clone(), cx);
                 });
 
                 cx.notify();
             })
-        }));
+        })
+        .detach_and_log_err(cx);
+        Ok(())
     }
 }
 
@@ -512,7 +687,7 @@ impl ToolCard for EditFileToolCard {
         };
 
         let path_label_button = h_flex()
-            .id(("edit-tool-path-label-button", self.editor_unique_id))
+            .id(("edit-tool-path-label-button", self.editor.entity_id()))
             .w_full()
             .max_w_full()
             .px_1()
@@ -611,7 +786,7 @@ impl ToolCard for EditFileToolCard {
                         )
                         .child(
                             Disclosure::new(
-                                ("edit-file-error-disclosure", self.editor_unique_id),
+                                ("edit-file-error-disclosure", self.editor.entity_id()),
                                 self.error_expanded.is_some(),
                             )
                             .opened_icon(IconName::ChevronUp)
@@ -633,10 +808,10 @@ impl ToolCard for EditFileToolCard {
                         ),
                 )
             })
-            .when(error_message.is_none() && self.has_diff(), |header| {
+            .when(error_message.is_none() && !self.is_loading(), |header| {
                 header.child(
                     Disclosure::new(
-                        ("edit-file-disclosure", self.editor_unique_id),
+                        ("edit-file-disclosure", self.editor.entity_id()),
                         self.preview_expanded,
                     )
                     .opened_icon(IconName::ChevronUp)
@@ -772,10 +947,10 @@ impl ToolCard for EditFileToolCard {
                         ),
                 )
             })
-            .when(!self.has_diff() && error_message.is_none(), |card| {
+            .when(self.is_loading() && error_message.is_none(), |card| {
                 card.child(waiting_for_diff)
             })
-            .when(self.preview_expanded && self.has_diff(), |card| {
+            .when(self.preview_expanded && !self.is_loading(), |card| {
                 card.child(
                     v_flex()
                         .relative()
@@ -797,7 +972,7 @@ impl ToolCard for EditFileToolCard {
                 .when(is_collapsible, |card| {
                     card.child(
                         h_flex()
-                            .id(("expand-button", self.editor_unique_id))
+                            .id(("expand-button", self.editor.entity_id()))
                             .flex_none()
                             .cursor_pointer()
                             .h_5()
@@ -871,19 +1046,23 @@ async fn build_buffer(
 }
 
 async fn build_buffer_diff(
-    mut old_text: String,
+    old_text: Arc<String>,
     buffer: &Entity<Buffer>,
     language_registry: &Arc<LanguageRegistry>,
     cx: &mut AsyncApp,
 ) -> Result<Entity<BufferDiff>> {
-    LineEnding::normalize(&mut old_text);
-
     let buffer = cx.update(|cx| buffer.read(cx).snapshot())?;
 
+    let old_text_rope = cx
+        .background_spawn({
+            let old_text = old_text.clone();
+            async move { Rope::from(old_text.as_str()) }
+        })
+        .await;
     let base_buffer = cx
         .update(|cx| {
             Buffer::build_snapshot(
-                old_text.clone().into(),
+                old_text_rope,
                 buffer.language().cloned(),
                 Some(language_registry.clone()),
                 cx,
@@ -895,7 +1074,7 @@ async fn build_buffer_diff(
         .update(|cx| {
             BufferDiffSnapshot::new_with_base_buffer(
                 buffer.text.clone(),
-                Some(old_text.into()),
+                Some(old_text),
                 base_buffer,
                 cx,
             )

crates/language/src/syntax_map/syntax_map_tests.rs

@@ -1076,7 +1076,7 @@ fn test_edit_sequence(language_name: &str, steps: &[&str], cx: &mut App) -> (Buf
         .now_or_never()
         .unwrap()
         .unwrap();
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), Default::default());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "");
 
     let mut mutated_syntax_map = SyntaxMap::new(&buffer);
     mutated_syntax_map.set_language_registry(registry.clone());

crates/language_model/src/fake_provider.rs

@@ -107,14 +107,18 @@ impl FakeLanguageModel {
         self.current_completion_txs.lock().len()
     }
 
-    pub fn stream_completion_response(&self, request: &LanguageModelRequest, chunk: String) {
+    pub fn stream_completion_response(
+        &self,
+        request: &LanguageModelRequest,
+        chunk: impl Into<String>,
+    ) {
         let current_completion_txs = self.current_completion_txs.lock();
         let tx = current_completion_txs
             .iter()
             .find(|(req, _)| req == request)
             .map(|(_, tx)| tx)
             .unwrap();
-        tx.unbounded_send(chunk).unwrap();
+        tx.unbounded_send(chunk.into()).unwrap();
     }
 
     pub fn end_completion_stream(&self, request: &LanguageModelRequest) {
@@ -123,7 +127,7 @@ impl FakeLanguageModel {
             .retain(|(req, _)| req != request);
     }
 
-    pub fn stream_last_completion_response(&self, chunk: String) {
+    pub fn stream_last_completion_response(&self, chunk: impl Into<String>) {
         self.stream_completion_response(self.pending_completions().last().unwrap(), chunk);
     }
 

crates/project/src/buffer_store.rs

@@ -622,7 +622,7 @@ impl LocalBufferStore {
                 Ok(buffer) => Ok(buffer),
                 Err(error) if is_not_found_error(&error) => cx.new(|cx| {
                     let buffer_id = BufferId::from(cx.entity_id().as_non_zero_u64());
-                    let text_buffer = text::Buffer::new(0, buffer_id, "".into());
+                    let text_buffer = text::Buffer::new(0, buffer_id, "");
                     Buffer::build(
                         text_buffer,
                         Some(Arc::new(File {

crates/text/src/tests.rs

@@ -16,7 +16,7 @@ fn init_logger() {
 
 #[test]
 fn test_edit() {
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "abc".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "abc");
     assert_eq!(buffer.text(), "abc");
     buffer.edit([(3..3, "def")]);
     assert_eq!(buffer.text(), "abcdef");
@@ -175,7 +175,7 @@ fn test_line_endings() {
         LineEnding::Windows
     );
 
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "one\r\ntwo\rthree".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "one\r\ntwo\rthree");
     assert_eq!(buffer.text(), "one\ntwo\nthree");
     assert_eq!(buffer.line_ending(), LineEnding::Windows);
     buffer.check_invariants();
@@ -189,7 +189,7 @@ fn test_line_endings() {
 
 #[test]
 fn test_line_len() {
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "");
     buffer.edit([(0..0, "abcd\nefg\nhij")]);
     buffer.edit([(12..12, "kl\nmno")]);
     buffer.edit([(18..18, "\npqrs\n")]);
@@ -206,7 +206,7 @@ fn test_line_len() {
 #[test]
 fn test_common_prefix_at_position() {
     let text = "a = str; b = δα";
-    let buffer = Buffer::new(0, BufferId::new(1).unwrap(), text.into());
+    let buffer = Buffer::new(0, BufferId::new(1).unwrap(), text);
 
     let offset1 = offset_after(text, "str");
     let offset2 = offset_after(text, "δα");
@@ -257,7 +257,7 @@ fn test_text_summary_for_range() {
     let buffer = Buffer::new(
         0,
         BufferId::new(1).unwrap(),
-        "ab\nefg\nhklm\nnopqrs\ntuvwxyz".into(),
+        "ab\nefg\nhklm\nnopqrs\ntuvwxyz",
     );
     assert_eq!(
         buffer.text_summary_for_range::<TextSummary, _>(0..2),
@@ -347,7 +347,7 @@ fn test_text_summary_for_range() {
 
 #[test]
 fn test_chars_at() {
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "");
     buffer.edit([(0..0, "abcd\nefgh\nij")]);
     buffer.edit([(12..12, "kl\nmno")]);
     buffer.edit([(18..18, "\npqrs")]);
@@ -369,7 +369,7 @@ fn test_chars_at() {
     assert_eq!(chars.collect::<String>(), "PQrs");
 
     // Regression test:
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "");
     buffer.edit([(0..0, "[workspace]\nmembers = [\n    \"xray_core\",\n    \"xray_server\",\n    \"xray_cli\",\n    \"xray_wasm\",\n]\n")]);
     buffer.edit([(60..60, "\n")]);
 
@@ -379,7 +379,7 @@ fn test_chars_at() {
 
 #[test]
 fn test_anchors() {
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "");
     buffer.edit([(0..0, "abc")]);
     let left_anchor = buffer.anchor_before(2);
     let right_anchor = buffer.anchor_after(2);
@@ -497,7 +497,7 @@ fn test_anchors() {
 
 #[test]
 fn test_anchors_at_start_and_end() {
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "");
     let before_start_anchor = buffer.anchor_before(0);
     let after_end_anchor = buffer.anchor_after(0);
 
@@ -520,7 +520,7 @@ fn test_anchors_at_start_and_end() {
 
 #[test]
 fn test_undo_redo() {
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "1234".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "1234");
     // Set group interval to zero so as to not group edits in the undo stack.
     buffer.set_group_interval(Duration::from_secs(0));
 
@@ -557,7 +557,7 @@ fn test_undo_redo() {
 #[test]
 fn test_history() {
     let mut now = Instant::now();
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "123456".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "123456");
     buffer.set_group_interval(Duration::from_millis(300));
 
     let transaction_1 = buffer.start_transaction_at(now).unwrap();
@@ -624,7 +624,7 @@ fn test_history() {
 #[test]
 fn test_finalize_last_transaction() {
     let now = Instant::now();
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "123456".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "123456");
     buffer.history.group_interval = Duration::from_millis(1);
 
     buffer.start_transaction_at(now);
@@ -660,7 +660,7 @@ fn test_finalize_last_transaction() {
 #[test]
 fn test_edited_ranges_for_transaction() {
     let now = Instant::now();
-    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "1234567".into());
+    let mut buffer = Buffer::new(0, BufferId::new(1).unwrap(), "1234567");
 
     buffer.start_transaction_at(now);
     buffer.edit([(2..4, "cd")]);
@@ -699,9 +699,9 @@ fn test_edited_ranges_for_transaction() {
 fn test_concurrent_edits() {
     let text = "abcdef";
 
-    let mut buffer1 = Buffer::new(1, BufferId::new(1).unwrap(), text.into());
-    let mut buffer2 = Buffer::new(2, BufferId::new(1).unwrap(), text.into());
-    let mut buffer3 = Buffer::new(3, BufferId::new(1).unwrap(), text.into());
+    let mut buffer1 = Buffer::new(1, BufferId::new(1).unwrap(), text);
+    let mut buffer2 = Buffer::new(2, BufferId::new(1).unwrap(), text);
+    let mut buffer3 = Buffer::new(3, BufferId::new(1).unwrap(), text);
 
     let buf1_op = buffer1.edit([(1..2, "12")]);
     assert_eq!(buffer1.text(), "a12cdef");

crates/text/src/text.rs

@@ -677,7 +677,8 @@ impl FromIterator<char> for LineIndent {
 }
 
 impl Buffer {
-    pub fn new(replica_id: u16, remote_id: BufferId, mut base_text: String) -> Buffer {
+    pub fn new(replica_id: u16, remote_id: BufferId, base_text: impl Into<String>) -> Buffer {
+        let mut base_text = base_text.into();
         let line_ending = LineEnding::detect(&base_text);
         LineEnding::normalize(&mut base_text);
         Self::new_normalized(replica_id, remote_id, line_ending, Rope::from(base_text))