chore(code): support multiple selections in tab

packages/codemirror/src/extensions/custom_tab.ts

@@ -1,4 +1,5 @@
 import { indentLess, indentMore } from "@codemirror/commands";
+import { EditorSelection, type ChangeSpec } from "@codemirror/state";
 import type { KeyBinding } from "@codemirror/view";
 
 const smartIndentWithTab: KeyBinding[] = [
@@ -7,33 +8,39 @@ const smartIndentWithTab: KeyBinding[] = [
         run({ state, dispatch }) {
             const { selection } = state;
 
-            for (const range of selection.ranges) {
+            // Handle selection indenting normally
-                if (!range.empty) {
+            if (selection.ranges.some(range => !range.empty)) {
-                    // Allow default behaviour.
+                return indentMore({ state, dispatch });
-                    return false;
             }
 
+            const changes = [];
+            const newSelections = [];
+
+            for (let range of selection.ranges) {
                 const line = state.doc.lineAt(range.head);
                 const beforeCursor = state.doc.sliceString(line.from, range.head);
 
                 if (/^\s*$/.test(beforeCursor)) {
-                    // Only whitespace before cursor: indent line
+                    // Only whitespace before cursor → indent line
                     return indentMore({ state, dispatch });
                 } else {
-                    // Insert a tab character
+                    // Insert a tab character at cursor
-                    const cursor = range.head;
+                    changes.push({ from: range.head, to: range.head, insert: "\t" });
-                    dispatch(state.update({
+                    newSelections.push(EditorSelection.cursor(range.head + 1));
-                        changes: {
+                }
-                            from: cursor,
+            }
-                            insert: "\t"
+
-                        },
+            if (changes.length) {
-                        selection: { anchor: cursor + 1 },
+                dispatch(
+                    state.update({
+                        changes,
+                        selection: EditorSelection.create(newSelections),
                         scrollIntoView: true,
                         userEvent: "input"
-                    }));
+                    })
+                );
                 return true;
             }
-            }
 
             return false;
         },