feat(json-crdt): 🎸 add ArrApi.upd() method

Author: streamich

src/json-crdt/model/api/__tests__/ArrayApi.spec.ts

@@ -14,13 +14,28 @@ test('can insert a value and delete all previous ones', () => {
   expect(arr.view()).toEqual([42, 69]);
 });
 
-test('.length()', () => {
-  const doc = Model.create();
-  doc.api.set({
-    arr: [1, 2, 3],
+describe('.length()', () => {
+  test('returns "arr" length', () => {
+    const doc = Model.create();
+    doc.api.set({
+      arr: [1, 2, 3],
+    });
+    const arr = doc.api.arr(['arr']);
+    expect(arr.length()).toBe(3);
+  });
+});
+
+describe('.upd()', () => {
+  test('can update array element', () => {
+    const doc = Model.create([1, 2, 3]);
+    const arr = doc.$.$!;
+    expect(arr.view()).toEqual([1, 2, 3]);
+    arr.upd(1, 42);
+    expect(arr.view()).toEqual([1, 42, 3]);
+    arr.upd(2, 69);
+    arr.upd(1, 24);
+    expect(arr.view()).toEqual([1, 24, 69]);
   });
-  const arr = doc.api.arr(['arr']);
-  expect(arr.length()).toBe(3);
 });
 
 describe('events', () => {

src/json-crdt/model/api/nodes.ts

@@ -752,6 +752,17 @@ export class ArrApi<N extends ArrNode<any> = ArrNode<any>> extends NodeApi<N> {
     api.apply();
   }
 
+  // TODO: Implement `.push()` method.
+
+  public upd(index: number, value: JsonNodeView<N>[number]): void {
+    const {api, node} = this;
+    const ref = node.getId(index);
+    if (!ref) throw new Error('OUT_OF_BOUNDS');
+    const {builder} = api;
+    builder.updArr(node.id, ref, builder.constOrJson(value));
+    api.apply();
+  }
+
   /**
    * Deletes a range of elements at a given position.
    *