Duplicate Numbers Cause Incorrect Selection Behavior

[rajsite]

Description

When using an array of numbers as the items for iron-list, having duplicate values in the array causes the selection behavior to select the wrong item.

Expected outcome

The item at the index clicked is selected

Actual outcome

A different item with the same value, but at an index that was not clicked is selected

Live Demo

http://jsbin.com/jusenih/1/edit?html,output

Steps to reproduce

1. Open the jsbin and select (ie click) Item 3

2. Notice that it is Item 7 that has selected changed to true

Browsers Affected

• Firefox
• Safari 9
• Chrome
• Safari 8
• Safari 7
• Edge
• IE 11
• IE 10
  ^ Browsers reproducing the behavior
  ^ Firefox Nightly reproduces intermittently

[blasten]

Yep, this is known issue. Check Polymer/polymer#1913 for more reference. Is it possible for you to wrap the values in an object?

There's an explanatory PR by @kevinpschaaf around this issue in Polymer/polymer#3970 (comment) for Polymer 2.0.

[rajsite]

Ah I had missed that, thanks @blasten. I had noticed the behavior when playing with the jsbins referenced in the README when evaluating iron-list (which all demonstrate using an array of numbers).

I did not notice the same problem as my data set is an array of objects (although it did make me hesitant to use the iron-list element). I imagine the common use case in an array of objects instead of primitives. It might be useful to have the examples demonstrate that use case and / or have this limitation using arrays of primitives documented.

[rajsite]

The original question of this issue was definitely a duplicate of Polymer/polymer#1913

The second question of whether the jsbin examples should not demonstrate arrays of numbers as that causes strange behavior seems moot as the jsbin examples are non-functional: #465

I'll just close this issue and a separate issue could be opened for the jsbin iron-list examples using numerics.