Revert outline summarization (#3114)

This pull request essentially reverts #3067: we noticed that only using
the function signatures produces far worse results in codegen, and so
that feels like a regression compared to before. We should re-enable
this once we have a smarter approach to fetching context during codegen,
possibly when #3097 lands.

As a drive-by, we also fixed a longstanding bug that caused codegen to
include the final line of a selection even if the selection ended at the
start of the line.

Ideally, I'd like to hot fix this to preview so that it goes to stable
during the weekly release.

/cc: @KCaverly @nathansobo 

Release Notes:

- N/A

crates/assistant/src/assistant_panel.rs

@@ -17,7 +17,7 @@ use editor::{
         BlockContext, BlockDisposition, BlockId, BlockProperties, BlockStyle, ToDisplayPoint,
     },
     scroll::autoscroll::{Autoscroll, AutoscrollStrategy},
-    Anchor, Editor, MoveDown, MoveUp, MultiBufferSnapshot, ToOffset,
+    Anchor, Editor, MoveDown, MoveUp, MultiBufferSnapshot, ToOffset, ToPoint,
 };
 use fs::Fs;
 use futures::StreamExt;
@@ -278,22 +278,36 @@ impl AssistantPanel {
         if selection.start.excerpt_id() != selection.end.excerpt_id() {
             return;
         }
+        let snapshot = editor.read(cx).buffer().read(cx).snapshot(cx);
+
+        // Extend the selection to the start and the end of the line.
+        let mut point_selection = selection.map(|selection| selection.to_point(&snapshot));
+        if point_selection.end > point_selection.start {
+            point_selection.start.column = 0;
+            // If the selection ends at the start of the line, we don't want to include it.
+            if point_selection.end.column == 0 {
+                point_selection.end.row -= 1;
+            }
+            point_selection.end.column = snapshot.line_len(point_selection.end.row);
+        }
+
+        let codegen_kind = if point_selection.start == point_selection.end {
+            CodegenKind::Generate {
+                position: snapshot.anchor_after(point_selection.start),
+            }
+        } else {
+            CodegenKind::Transform {
+                range: snapshot.anchor_before(point_selection.start)
+                    ..snapshot.anchor_after(point_selection.end),
+            }
+        };
 
         let inline_assist_id = post_inc(&mut self.next_inline_assist_id);
-        let snapshot = editor.read(cx).buffer().read(cx).snapshot(cx);
         let provider = Arc::new(OpenAICompletionProvider::new(
             api_key,
             cx.background().clone(),
         ));
-        let codegen_kind = if editor.read(cx).selections.newest::<usize>(cx).is_empty() {
-            CodegenKind::Generate {
-                position: selection.start,
-            }
-        } else {
-            CodegenKind::Transform {
-                range: selection.start..selection.end,
-            }
-        };
+
         let codegen = cx.add_model(|cx| {
             Codegen::new(editor.read(cx).buffer().clone(), codegen_kind, provider, cx)
         });
@@ -319,7 +333,7 @@ impl AssistantPanel {
             editor.insert_blocks(
                 [BlockProperties {
                     style: BlockStyle::Flex,
-                    position: selection.head().bias_left(&snapshot),
+                    position: snapshot.anchor_before(point_selection.head()),
                     height: 2,
                     render: Arc::new({
                         let inline_assistant = inline_assistant.clone();
@@ -578,10 +592,7 @@ impl AssistantPanel {
 
         let codegen_kind = codegen.read(cx).kind().clone();
         let user_prompt = user_prompt.to_string();
-        let prompt = cx.background().spawn(async move {
-            let language_name = language_name.as_deref();
-            generate_content_prompt(user_prompt, language_name, &buffer, range, codegen_kind)
-        });
+
         let mut messages = Vec::new();
         let mut model = settings::get::<AssistantSettings>(cx)
             .default_open_ai_model
@@ -597,6 +608,11 @@ impl AssistantPanel {
             model = conversation.model.clone();
         }
 
+        let prompt = cx.background().spawn(async move {
+            let language_name = language_name.as_deref();
+            generate_content_prompt(user_prompt, language_name, &buffer, range, codegen_kind)
+        });
+
         cx.spawn(|_, mut cx| async move {
             let prompt = prompt.await;
 

crates/assistant/src/codegen.rs

@@ -1,9 +1,7 @@
 use crate::streaming_diff::{Hunk, StreamingDiff};
 use ai::completion::{CompletionProvider, OpenAIRequest};
 use anyhow::Result;
-use editor::{
-    multi_buffer, Anchor, AnchorRangeExt, MultiBuffer, MultiBufferSnapshot, ToOffset, ToPoint,
-};
+use editor::{multi_buffer, Anchor, MultiBuffer, MultiBufferSnapshot, ToOffset, ToPoint};
 use futures::{channel::mpsc, SinkExt, Stream, StreamExt};
 use gpui::{Entity, ModelContext, ModelHandle, Task};
 use language::{Rope, TransactionId};
@@ -40,26 +38,11 @@ impl Entity for Codegen {
 impl Codegen {
     pub fn new(
         buffer: ModelHandle<MultiBuffer>,
-        mut kind: CodegenKind,
+        kind: CodegenKind,
         provider: Arc<dyn CompletionProvider>,
         cx: &mut ModelContext<Self>,
     ) -> Self {
         let snapshot = buffer.read(cx).snapshot(cx);
-        match &mut kind {
-            CodegenKind::Transform { range } => {
-                let mut point_range = range.to_point(&snapshot);
-                point_range.start.column = 0;
-                if point_range.end.column > 0 || point_range.start.row == point_range.end.row {
-                    point_range.end.column = snapshot.line_len(point_range.end.row);
-                }
-                range.start = snapshot.anchor_before(point_range.start);
-                range.end = snapshot.anchor_after(point_range.end);
-            }
-            CodegenKind::Generate { position } => {
-                *position = position.bias_right(&snapshot);
-            }
-        }
-
         Self {
             provider,
             buffer: buffer.clone(),
@@ -386,7 +369,7 @@ mod tests {
         let buffer = cx.add_model(|cx| MultiBuffer::singleton(buffer, cx));
         let range = buffer.read_with(cx, |buffer, cx| {
             let snapshot = buffer.snapshot(cx);
-            snapshot.anchor_before(Point::new(1, 4))..snapshot.anchor_after(Point::new(4, 4))
+            snapshot.anchor_before(Point::new(1, 0))..snapshot.anchor_after(Point::new(4, 5))
         });
         let provider = Arc::new(TestCompletionProvider::new());
         let codegen = cx.add_model(|cx| {

crates/assistant/src/prompts.rs

@@ -4,6 +4,7 @@ use std::cmp::{self, Reverse};
 use std::fmt::Write;
 use std::ops::Range;
 
+#[allow(dead_code)]
 fn summarize(buffer: &BufferSnapshot, selected_range: Range<impl ToOffset>) -> String {
     #[derive(Debug)]
     struct Match {
@@ -121,6 +122,7 @@ pub fn generate_content_prompt(
     range: Range<impl ToOffset>,
     kind: CodegenKind,
 ) -> String {
+    let range = range.to_offset(buffer);
     let mut prompt = String::new();
 
     // General Preamble
@@ -130,17 +132,29 @@ pub fn generate_content_prompt(
         writeln!(prompt, "You're an expert engineer.\n").unwrap();
     }
 
-    let outline = summarize(buffer, range);
+    let mut content = String::new();
+    content.extend(buffer.text_for_range(0..range.start));
+    if range.start == range.end {
+        content.push_str("<|START|>");
+    } else {
+        content.push_str("<|START|");
+    }
+    content.extend(buffer.text_for_range(range.clone()));
+    if range.start != range.end {
+        content.push_str("|END|>");
+    }
+    content.extend(buffer.text_for_range(range.end..buffer.len()));
+
     writeln!(
         prompt,
-        "The file you are currently working on has the following outline:"
+        "The file you are currently working on has the following content:"
     )
     .unwrap();
     if let Some(language_name) = language_name {
         let language_name = language_name.to_lowercase();
-        writeln!(prompt, "```{language_name}\n{outline}\n```").unwrap();
+        writeln!(prompt, "```{language_name}\n{content}\n```").unwrap();
     } else {
-        writeln!(prompt, "```\n{outline}\n```").unwrap();
+        writeln!(prompt, "```\n{content}\n```").unwrap();
     }
 
     match kind {