Restructure workflow step resolution and fix inserting newlines (#15720)

Release Notes:

- N/A

---------

Co-authored-by: Nathan <nathan@zed.dev>

crates/language/Cargo.toml

@@ -53,6 +53,7 @@ settings.workspace = true
 similar.workspace = true
 smallvec.workspace = true
 smol.workspace = true
+strsim.workspace = true
 sum_tree.workspace = true
 task.workspace = true
 text.workspace = true

crates/language/src/buffer.rs

@@ -1876,6 +1876,63 @@ impl Buffer {
         cx.notify();
     }
 
+    // Inserts newlines at the given position to create an empty line, returning the start of the new line.
+    // You can also request the insertion of empty lines above and below the line starting at the returned point.
+    pub fn insert_empty_line(
+        &mut self,
+        position: impl ToPoint,
+        space_above: bool,
+        space_below: bool,
+        cx: &mut ModelContext<Self>,
+    ) -> Point {
+        let mut position = position.to_point(self);
+
+        self.start_transaction();
+
+        self.edit(
+            [(position..position, "\n")],
+            Some(AutoindentMode::EachLine),
+            cx,
+        );
+
+        if position.column > 0 {
+            position += Point::new(1, 0);
+        }
+
+        if !self.is_line_blank(position.row) {
+            self.edit(
+                [(position..position, "\n")],
+                Some(AutoindentMode::EachLine),
+                cx,
+            );
+        }
+
+        if space_above {
+            if position.row > 0 && !self.is_line_blank(position.row - 1) {
+                self.edit(
+                    [(position..position, "\n")],
+                    Some(AutoindentMode::EachLine),
+                    cx,
+                );
+                position.row += 1;
+            }
+        }
+
+        if space_below {
+            if position.row == self.max_point().row || !self.is_line_blank(position.row + 1) {
+                self.edit(
+                    [(position..position, "\n")],
+                    Some(AutoindentMode::EachLine),
+                    cx,
+                );
+            }
+        }
+
+        self.end_transaction(cx);
+
+        position
+    }
+
     /// Applies the given remote operations to the buffer.
     pub fn apply_ops<I: IntoIterator<Item = Operation>>(
         &mut self,

crates/language/src/buffer_tests.rs

@@ -1822,6 +1822,92 @@ fn test_autoindent_query_with_outdent_captures(cx: &mut AppContext) {
     });
 }
 
+#[gpui::test]
+fn test_insert_empty_line(cx: &mut AppContext) {
+    init_settings(cx, |_| {});
+
+    // Insert empty line at the beginning, requesting an empty line above
+    cx.new_model(|cx| {
+        let mut buffer = Buffer::local("abc\ndef\nghi", cx);
+        let point = buffer.insert_empty_line(Point::new(0, 0), true, false, cx);
+        assert_eq!(buffer.text(), "\nabc\ndef\nghi");
+        assert_eq!(point, Point::new(0, 0));
+        buffer
+    });
+
+    // Insert empty line at the beginning, requesting an empty line above and below
+    cx.new_model(|cx| {
+        let mut buffer = Buffer::local("abc\ndef\nghi", cx);
+        let point = buffer.insert_empty_line(Point::new(0, 0), true, true, cx);
+        assert_eq!(buffer.text(), "\n\nabc\ndef\nghi");
+        assert_eq!(point, Point::new(0, 0));
+        buffer
+    });
+
+    // Insert empty line at the start of a line, requesting empty lines above and below
+    cx.new_model(|cx| {
+        let mut buffer = Buffer::local("abc\ndef\nghi", cx);
+        let point = buffer.insert_empty_line(Point::new(2, 0), true, true, cx);
+        assert_eq!(buffer.text(), "abc\ndef\n\n\n\nghi");
+        assert_eq!(point, Point::new(3, 0));
+        buffer
+    });
+
+    // Insert empty line in the middle of a line, requesting empty lines above and below
+    cx.new_model(|cx| {
+        let mut buffer = Buffer::local("abc\ndefghi\njkl", cx);
+        let point = buffer.insert_empty_line(Point::new(1, 3), true, true, cx);
+        assert_eq!(buffer.text(), "abc\ndef\n\n\n\nghi\njkl");
+        assert_eq!(point, Point::new(3, 0));
+        buffer
+    });
+
+    // Insert empty line in the middle of a line, requesting empty line above only
+    cx.new_model(|cx| {
+        let mut buffer = Buffer::local("abc\ndefghi\njkl", cx);
+        let point = buffer.insert_empty_line(Point::new(1, 3), true, false, cx);
+        assert_eq!(buffer.text(), "abc\ndef\n\n\nghi\njkl");
+        assert_eq!(point, Point::new(3, 0));
+        buffer
+    });
+
+    // Insert empty line in the middle of a line, requesting empty line below only
+    cx.new_model(|cx| {
+        let mut buffer = Buffer::local("abc\ndefghi\njkl", cx);
+        let point = buffer.insert_empty_line(Point::new(1, 3), false, true, cx);
+        assert_eq!(buffer.text(), "abc\ndef\n\n\nghi\njkl");
+        assert_eq!(point, Point::new(2, 0));
+        buffer
+    });
+
+    // Insert empty line at the end, requesting empty lines above and below
+    cx.new_model(|cx| {
+        let mut buffer = Buffer::local("abc\ndef\nghi", cx);
+        let point = buffer.insert_empty_line(Point::new(2, 3), true, true, cx);
+        assert_eq!(buffer.text(), "abc\ndef\nghi\n\n\n");
+        assert_eq!(point, Point::new(4, 0));
+        buffer
+    });
+
+    // Insert empty line at the end, requesting empty line above only
+    cx.new_model(|cx| {
+        let mut buffer = Buffer::local("abc\ndef\nghi", cx);
+        let point = buffer.insert_empty_line(Point::new(2, 3), true, false, cx);
+        assert_eq!(buffer.text(), "abc\ndef\nghi\n\n");
+        assert_eq!(point, Point::new(4, 0));
+        buffer
+    });
+
+    // Insert empty line at the end, requesting empty line below only
+    cx.new_model(|cx| {
+        let mut buffer = Buffer::local("abc\ndef\nghi", cx);
+        let point = buffer.insert_empty_line(Point::new(2, 3), false, true, cx);
+        assert_eq!(buffer.text(), "abc\ndef\nghi\n\n");
+        assert_eq!(point, Point::new(3, 0));
+        buffer
+    });
+}
+
 #[gpui::test]
 fn test_language_scope_at_with_javascript(cx: &mut AppContext) {
     init_settings(cx, |_| {});

crates/language/src/outline.rs

@@ -1,3 +1,4 @@
+use crate::{BufferSnapshot, Point, ToPoint};
 use fuzzy::{StringMatch, StringMatchCandidate};
 use gpui::{relative, AppContext, BackgroundExecutor, HighlightStyle, StyledText, TextStyle};
 use settings::Settings;
@@ -24,6 +25,27 @@ pub struct OutlineItem<T> {
     pub annotation_range: Option<Range<T>>,
 }
 
+impl<T: ToPoint> OutlineItem<T> {
+    /// Converts to an equivalent outline item, but with parameterized over Points.
+    pub fn to_point(&self, buffer: &BufferSnapshot) -> OutlineItem<Point> {
+        OutlineItem {
+            depth: self.depth,
+            range: self.range.start.to_point(buffer)..self.range.end.to_point(buffer),
+            text: self.text.clone(),
+            highlight_ranges: self.highlight_ranges.clone(),
+            name_ranges: self.name_ranges.clone(),
+            body_range: self
+                .body_range
+                .as_ref()
+                .map(|r| r.start.to_point(buffer)..r.end.to_point(buffer)),
+            annotation_range: self
+                .annotation_range
+                .as_ref()
+                .map(|r| r.start.to_point(buffer)..r.end.to_point(buffer)),
+        }
+    }
+}
+
 impl<T> Outline<T> {
     pub fn new(items: Vec<OutlineItem<T>>) -> Self {
         let mut candidates = Vec::new();
@@ -62,6 +84,16 @@ impl<T> Outline<T> {
         }
     }
 
+    /// Find the most similar symbol to the provided query according to the Jaro-Winkler distance measure.
+    pub fn find_most_similar(&self, query: &str) -> Option<&OutlineItem<T>> {
+        let candidate = self.path_candidates.iter().max_by(|a, b| {
+            strsim::jaro_winkler(&a.string, query)
+                .total_cmp(&strsim::jaro_winkler(&b.string, query))
+        })?;
+        Some(&self.items[candidate.id])
+    }
+
+    /// Find all outline symbols according to a longest subsequence match with the query, ordered descending by match score.
     pub async fn search(&self, query: &str, executor: BackgroundExecutor) -> Vec<StringMatch> {
         let query = query.trim_start();
         let is_path_query = query.contains(' ');