feat(json-crdt-peritext-ui): 🎸 add ability to delete at arbitrary pos…

…ition

src/json-crdt-peritext-ui/events/PeritextEventTarget.ts

@@ -29,8 +29,8 @@ export class PeritextEventTarget extends TypedEventTarget<PeritextEventMap> {
     this.dispatch('insert', {text});
   }
 
-  public delete(len: DeleteDetail['len'], unit?: DeleteDetail['unit']): void {
-    this.dispatch('delete', {len, unit});
+  public delete(len: DeleteDetail['len'], unit?: DeleteDetail['unit'], at?: DeleteDetail['at']): void {
+    this.dispatch('delete', {len, unit, at});
   }
 
   public cursor(detail: CursorDetail): void {

src/json-crdt-peritext-ui/events/__tests__/delete.spec.ts

@@ -159,6 +159,28 @@ const testSuite = (getKit: () => Kit) => {
       kit.et.delete(DIRECTION, 'word');
       expect(kit.editor.text()).toBe('abcde  klmnopqrstuvwxyz');
     });
+
+    test('can delete a word at specific position', async () => {
+      const kit = setup();
+      kit.editor.cursor.setAt(10);
+      kit.et.insert(' ');
+      kit.editor.cursor.setAt(5);
+      kit.et.insert(' ');
+      kit.editor.delCursors();
+      expect(kit.editor.text()).toBe('abcde fghij klmnopqrstuvwxyz');
+      kit.et.delete(0, 'word', 8);
+      expect(kit.editor.text()).toBe('abcde  klmnopqrstuvwxyz');
+      expect(kit.editor.cursor.start.viewPos()).toBe(6);
+      expect(kit.editor.cursor.isCollapsed()).toBe(true);
+      kit.et.delete(0, 'word', 3);
+      expect(kit.editor.text()).toBe('  klmnopqrstuvwxyz');
+      expect(kit.editor.cursor.start.viewPos()).toBe(0);
+      expect(kit.editor.cursor.isCollapsed()).toBe(true);
+      kit.et.delete(0, 'word', 10);
+      expect(kit.editor.text()).toBe('  ');
+      expect(kit.editor.cursor.start.viewPos()).toBe(2);
+      expect(kit.editor.cursor.isCollapsed()).toBe(true);
+    });
   });
 
   describe('lines', () => {

src/json-crdt-peritext-ui/events/types.ts

@@ -1,4 +1,5 @@
 import type {Point} from '../../json-crdt-extensions/peritext/rga/Point';
+import type {Position as EditorPosition} from '../../json-crdt-extensions/peritext/editor/types';
 import type {SliceType} from '../../json-crdt-extensions/peritext/slice/types';
 
 /**
@@ -57,6 +58,17 @@ export interface DeleteDetail {
    * @default 'char'
    */
   unit?: 'char' | 'word' | 'line';
+
+  /**
+   * Position in the document to start the deletion from. If not specified, the
+   * deletion is executed for all cursors in the document at their current
+   * positions. If specified, only one cursor will be placed at the specified
+   * position and the deletion will be executed from that position (while all
+   * other cursors will be removed).
+   * 
+   * @default undefined
+   */
+  at?: Position;
 }
 
 /**
@@ -117,7 +129,7 @@ export interface CursorDetail {
    * second `0 | 1` member specifies the anchor point of the character: `0`
    * for the beginning of the character and `1` for the end of the character.
    */
-  at?: number | [at: number, anchor: 0 | 1] | Point;
+  at?: Position;
 
   /**
    * Specify the length of the movement or selection in units specified by the
@@ -164,6 +176,21 @@ export interface InlineDetail {
 // biome-ignore lint: empty interface is expected
 export type MarkerDetail = {};
 
+/**
+ * Position represents a caret position in the document. The position can either
+ * be an instance of {@link Point} or a numeric position in the document, which
+ * will be immediately converted to a {@link Point} instance.
+ * 
+ * If a number is provided, the number represents the character index in the
+ * document, where `0` is the beginning of the document and `1` is the position
+ * right after the first character, etc.
+ *
+ * If 2-tuple is provided, the first element is the character index and the
+ * second `0 | 1` member specifies the anchor point of the character: `0`
+ * for the beginning of the character and `1` for the end of the character.
+ */
+export type Position = EditorPosition<string>;
+
 export type PeritextEventMap = {
   change: ChangeDetail;
   insert: InsertDetail;