Apply completion edits to all cursors

helix-lsp/src/lib.rs

@@ -57,7 +57,7 @@ pub enum OffsetEncoding {
 
 pub mod util {
     use super::*;
-    use helix_core::{diagnostic::NumberOrString, Range, Rope, Transaction};
+    use helix_core::{diagnostic::NumberOrString, Range, Rope, Selection, Tendril, Transaction};
 
     /// Converts a diagnostic in the document to [`lsp::Diagnostic`].
     ///
@@ -195,6 +195,42 @@ pub mod util {
         Some(Range::new(start, end))
     }
 
+    /// Creates a [Transaction] from the [lsp::TextEdit] in a completion response.
+    /// The transaction applies the edit to all cursors.
+    pub fn generate_transaction_from_completion_edit(
+        doc: &Rope,
+        selection: &Selection,
+        edit: lsp::TextEdit,
+        offset_encoding: OffsetEncoding,
+    ) -> Transaction {
+        let replacement: Option<Tendril> = if edit.new_text.is_empty() {
+            None
+        } else {
+            Some(edit.new_text.into())
+        };
+
+        let text = doc.slice(..);
+        let primary_cursor = selection.primary().cursor(text);
+
+        let start_offset = match lsp_pos_to_pos(doc, edit.range.start, offset_encoding) {
+            Some(start) => start as i128 - primary_cursor as i128,
+            None => return Transaction::new(doc),
+        };
+        let end_offset = match lsp_pos_to_pos(doc, edit.range.end, offset_encoding) {
+            Some(end) => end as i128 - primary_cursor as i128,
+            None => return Transaction::new(doc),
+        };
+
+        Transaction::change_by_selection(doc, selection, |range| {
+            let cursor = range.cursor(text);
+            (
+                (cursor as i128 + start_offset) as usize,
+                (cursor as i128 + end_offset) as usize,
+                replacement.clone(),
+            )
+        })
+    }
+
     pub fn generate_transaction_from_edits(
         doc: &Rope,
         mut edits: Vec<lsp::TextEdit>,

helix-term/src/ui/completion.rs

@@ -1,5 +1,5 @@
 use crate::compositor::{Component, Context, Event, EventResult};
-use helix_view::{apply_transaction, editor::CompleteAction};
+use helix_view::{apply_transaction, editor::CompleteAction, ViewId};
 use tui::buffer::Buffer as Surface;
 use tui::text::Spans;
 
@@ -107,6 +107,7 @@ impl Completion {
         let menu = Menu::new(items, (), move |editor: &mut Editor, item, event| {
             fn item_to_transaction(
                 doc: &Document,
+                view_id: ViewId,
                 item: &CompletionItem,
                 offset_encoding: helix_lsp::OffsetEncoding,
                 start_offset: usize,
@@ -121,9 +122,10 @@ impl Completion {
                         }
                     };
 
-                    util::generate_transaction_from_edits(
+                    util::generate_transaction_from_completion_edit(
                         doc.text(),
-                        vec![edit],
+                        doc.selection(view_id),
+                        edit,
                         offset_encoding, // TODO: should probably transcode in Client
                     )
                 } else {
@@ -132,10 +134,23 @@ impl Completion {
                     // in these cases we need to check for a common prefix and remove it
                     let prefix = Cow::from(doc.text().slice(start_offset..trigger_offset));
                     let text = text.trim_start_matches::<&str>(&prefix);
-                    Transaction::change(
-                        doc.text(),
-                        vec![(trigger_offset, trigger_offset, Some(text.into()))].into_iter(),
-                    )
+
+                    // TODO: this needs to be true for the numbers to work out correctly
+                    // in the closure below. It's passed in to a callback as this same
+                    // formula, but can the value change between the LSP request and
+                    // response? If it does, can we recover?
+                    debug_assert!(
+                        doc.selection(view_id)
+                            .primary()
+                            .cursor(doc.text().slice(..))
+                            == trigger_offset
+                    );
+
+                    Transaction::change_by_selection(doc.text(), doc.selection(view_id), |range| {
+                        let cursor = range.cursor(doc.text().slice(..));
+
+                        (cursor, cursor, Some(text.into()))
+                    })
                 };
 
                 transaction
@@ -164,6 +179,7 @@ impl Completion {
 
                     let transaction = item_to_transaction(
                         doc,
+                        view.id,
                         item,
                         offset_encoding,
                         start_offset,
@@ -185,6 +201,7 @@ impl Completion {
 
                     let transaction = item_to_transaction(
                         doc,
+                        view.id,
                         item,
                         offset_encoding,
                         start_offset,