editor: Change to pass cursor as offset for completions method. (#1271)

And to support `filter_text` as completion item highlight match.

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
         run: script/bootstrap
       - name: Machete
         if: ${{ matrix.run_on == 'macos-latest' }}
-        uses: bnjbvr/cargo-machete@main
+        uses: bnjbvr/cargo-machete@v0.9.1
       - name: Setup | Cache Cargo
         uses: actions/cache@v4
         with:

crates/story/examples/editor.rs

@@ -167,7 +167,7 @@ impl ExampleLspStore {
 }
 
 fn completion_item(
-    range: &lsp_types::Range,
+    replace_range: &lsp_types::Range,
     label: &str,
     replace_text: &str,
     documentation: &str,
@@ -177,8 +177,8 @@ fn completion_item(
         kind: Some(lsp_types::CompletionItemKind::FUNCTION),
         text_edit: Some(CompletionTextEdit::InsertAndReplace(InsertReplaceEdit {
             new_text: replace_text.to_string(),
-            insert: range.clone(),
+            insert: replace_range.clone(),
-            replace: range.clone(),
+            replace: replace_range.clone(),
         })),
         documentation: Some(lsp_types::Documentation::String(documentation.to_string())),
         insert_text: None,
@@ -204,33 +204,28 @@ impl CompletionProvider for ExampleLspStore {
         let rope = rope.clone();
         let items = self.completions.clone();
         cx.background_spawn(async move {
-            let pos = rope.offset_to_position(offset);
-
             // Simulate a slow completion source, to test Editor async handling.
             smol::Timer::after(Duration::from_millis(20)).await;
 
-            let range = lsp_types::Range::new(
-                pos,
-                lsp_types::Position {
-                    line: pos.line,
-                    character: pos.character + 1,
-                },
-            );
-
             if trigger_character.starts_with("/") {
+                let start = offset.saturating_sub(trigger_character.len());
+                let start_pos = rope.offset_to_position(start);
+                let end_pos = rope.offset_to_position(offset);
+                let replace_range = lsp_types::Range::new(start_pos, end_pos);
+
                 let items = vec![
                     completion_item(
-                        &range,
+                        &replace_range,
                         "/date",
                         format!("{}", chrono::Local::now().date_naive()).as_str(),
                         "Insert current date",
                     ),
-                    completion_item(&range, "/thanks", "Thank you!", "Insert Thank you!"),
+                    completion_item(&replace_range, "/thanks", "Thank you!", "Insert Thank you!"),
-                    completion_item(&range, "/+1", "👍", "Insert 👍"),
+                    completion_item(&replace_range, "/+1", "👍", "Insert 👍"),
-                    completion_item(&range, "/-1", "👎", "Insert 👎"),
+                    completion_item(&replace_range, "/-1", "👎", "Insert 👎"),
-                    completion_item(&range, "/smile", "😊", "Insert 😊"),
+                    completion_item(&replace_range, "/smile", "😊", "Insert 😊"),
-                    completion_item(&range, "/sad", "😢", "Insert 😢"),
+                    completion_item(&replace_range, "/sad", "😢", "Insert 😢"),
-                    completion_item(&range, "/launch", "🚀", "Insert 🚀"),
+                    completion_item(&replace_range, "/launch", "🚀", "Insert 🚀"),
                 ];
                 return Ok(CompletionResponse::Array(items));
             }

crates/ui/src/input/lsp/completions.rs

@@ -13,6 +13,8 @@ use crate::input::{
 pub trait CompletionProvider {
     /// Fetches completions based on the given byte offset.
     ///
+    /// - The `offset` is in bytes of current cursor.
+    ///
     /// textDocument/completion
     ///
     /// https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_completion
@@ -107,7 +109,7 @@ impl InputState {
         };
 
         let provider_responses =
-            provider.completions(&self.text, start_offset, completion_context, window, cx);
+            provider.completions(&self.text, new_offset, completion_context, window, cx);
         self._context_menu_task = cx.spawn_in(window, async move |editor, cx| {
             let mut completions: Vec<CompletionItem> = vec![];
             if let Some(provider_responses) = provider_responses.await.ok() {

crates/ui/src/input/popovers/completion_menu.rs

@@ -48,7 +48,7 @@ struct CompletionMenuItem {
     item: Rc<CompletionItem>,
     children: Vec<AnyElement>,
     selected: bool,
-    highlight_prefix_len: usize,
+    highlight_prefix: SharedString,
 }
 
 impl CompletionMenuItem {
@@ -58,12 +58,12 @@ impl CompletionMenuItem {
             item,
             children: vec![],
             selected: false,
-            highlight_prefix_len: 0,
+            highlight_prefix: "".into(),
         }
     }
 
-    fn highlight_prefix(mut self, len: usize) -> Self {
+    fn highlight_prefix(mut self, s: impl Into<SharedString>) -> Self {
-        self.highlight_prefix_len = len;
+        self.highlight_prefix = s.into();
         self
     }
 }
@@ -88,7 +88,12 @@ impl RenderOnce for CompletionMenuItem {
         let item = self.item;
 
         let deprecated = item.deprecated.unwrap_or(false);
-        let matched_len = self.highlight_prefix_len;
+        let matched_len = item
+            .filter_text
+            .as_ref()
+            .map(|s| s.len())
+            .unwrap_or(self.highlight_prefix.len());
+
         let highlights = vec![(
             0..matched_len,
             HighlightStyle {
@@ -139,8 +144,7 @@ impl ListDelegate for ContextMenuDelegate {
         _: &mut Context<List<Self>>,
     ) -> Option<Self::Item> {
         let item = self.items.get(ix.row)?;
-        let matched_len = self.query.len();
+        Some(CompletionMenuItem::new(ix.row, item.clone()).highlight_prefix(self.query.clone()))
-        Some(CompletionMenuItem::new(ix.row, item.clone()).highlight_prefix(matched_len))
     }
 
     fn set_selected_index(