Applying consecutive .splice on array of primitives with overlapping values fails

[tomalec]

Description

I try to apply .splice consecutively on same element, to alter the array of primitive values. When new value in splice is equal to any existing one (in different place), rendered result and data object gets corrupted.

Live Demo

http://jsbin.com/bimipe/edit?html,console,output

Steps to Reproduce

Example:

1. Create a template with

   <template is="dom-repeat" items="{{array}}">
     <li>{{item}}</li>
   </template>

2. Set model.array = [0,1]

3. Check that you can see:

   • 0
   • 1

4. Try to change array[0] to 1 and array[1] to 2 with splice method:

   domBind.splice("array", 0, 1, 1);
   domBind.splice("array", 1, 1, 2);

Expected Results

The DOM should be changed to reflect [1,2]:

• 1
• 2

Actual Results

Corrupted result is rendered:

•  
• 2

Browsers Affected

• Chrome
• Firefox
• ? Edge
• ? Safari 9
• ? Safari 8
• IE 11

Versions

• Polymer: v1.4.0
• webcomponents: v0.7.22

Investigation notes

• Replacing these items with unique ones works fine

  domBind.splice("array", 0, 1, 2);
  domBind.splice("array", 1, 1, 3);

• Calling each splice individually works:

  domBind.splice("array", 0, 1, 1);

  or

  domBind.splice("array", 1, 1, 2);

• Calling them asynchronously works:

  domBind.splice("array", 0, 1, 1);
  setTimeout(function(){
    domBind.splice("array", 1, 1, 2);
  });

• Even though "normalized" is not defined anywhere (Notifying consecutive array changes #2752 (comment)), when the splices are executed in anti-normalized order (last index to first), it also works

  domBind.splice("array", 1, 1, 2);
  domBind.splice("array", 0, 1, 1);

I suspect DOM binding engine thinks first 1 is the same object as one introduced in spliced and messes things up.

[warpech]

+1

[miyconst]

+1

[jfrazzano]

Was this resolved? It's an issue with use of set object for faux dirty check. Ira into same issue in independent bind system. If issue still exists. More than willing to pr and doc it let me know. Thanks and good luck. J

On Thu, Jun 22, 2017 at 4:51 AM Konstantin ***@***.***> wrote: +1 — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#3682 (comment)>, or mute the thread </~https://github.com/notifications/unsubscribe-auth/AHxnvkkIJAJbGWRLy7gBhA3ZvzQ_gEGkks5sGir9gaJpZM4IpVvo> .

--

…

_________________________________ Jason C. Frazzano Esq. Founder and Master Coach, Focused Coaching Stanford University, B.A. M.A., with honors and distinction Columbia Law School, J.D., Stone Scholar www.focusedcoaching.com jason@focusedcoaching.com jfrazzano@gmail.com office: 732-671-1834

[warpech]

This is not resolved yet.

[alshakero]

Update: this behavior seems to be fixed in Polymer 2.x.

[TimvdLippe]

Confirmed this has been fixed in Polymer 2: http://jsbin.com/pawopihera/edit?html,console,output