Merge pull request #349 from bigopon/fix-repeat-mutation

fix(Repeat): ignore mutation while processing instance changed

src/repeat.js

@@ -135,7 +135,11 @@ export class Repeat extends AbstractRepeater {
     if (!this.isOneTime && !this._observeInnerCollection()) {
       this._observeCollection();
     }
+    this.ignoreMutation = true;
     this.strategy.instanceChanged(this, items);
+    this.observerLocator.taskQueue.queueMicroTask(() => {
+      this.ignoreMutation = false;
+    });
   }
 
   _getInnerCollection() {
@@ -153,6 +157,9 @@ export class Repeat extends AbstractRepeater {
     if (!this.collectionObserver) {
       return;
     }
+    if (this.ignoreMutation) {
+      return;
+    }
     this.strategy.instanceMutated(this, collection, changes);
   }
 

test/repeat-integration.spec.js

@@ -1031,6 +1031,29 @@ describe('Repeat array (pure)', describeArrayTests.bind(this, true));
 
 describe('Repeat array (not pure)', describeArrayTests.bind(this, false));
 
+describe('instancesChanges and instancesMutated together', () => {
+  it('handles  together correctly', () => {
+    let template = `<template><section if.bind='show'><div repeat.for="item of items">\${item}</div></section></template>`;
+    let viewModel = {
+      show: false,
+      // items: [{ a: 'a' }, { a: 'b' }]
+      items: null,
+    };
+    let controller = createController(template, viewModel, false);
+    let taskQueue = container.get(TaskQueue);
+    taskQueue.queueMicroTask(() => {
+      viewModel.show = true;
+      viewModel.items = ['a', 'b', 'c', 'd'];
+      viewModel.items.splice(1, 1, { a: 'bb' });
+      viewModel.items.push({ a: 'aa' });
+    });
+    taskQueue.flushMicroTaskQueue();
+    taskQueue.queueMicroTask(() => {
+      console.log(host.children.length, select(controller, 'div').length);
+    });
+  });
+});
+
 describe('Repeat map [k, v]', () => {
   let viewModel, controller;
   let obj = {};