| Conditions | 1 | 
| Paths | 1 | 
| Total Lines | 15 | 
| Lines | 0 | 
| Ratio | 0 % | 
| Changes | 1 | ||
| Bugs | 0 | Features | 1 | 
| 1 | (function() { | ||
| 10 |         onStackClick: function() { | ||
| 11 | |||
| 12 |             document.querySelectorAll('.stack').forEach(function(item) { | ||
| 13 | item.style.display = 'none'; | ||
| 14 | }); | ||
| 15 | |||
| 16 |             document.querySelectorAll('.previousStack').forEach(function(item) { | ||
| 17 |                 item.classList.remove('selected'); | ||
| 18 | }); | ||
| 19 | |||
| 20 |             this.classList.add('selected'); | ||
| 21 | |||
| 22 | document.getElementById(this.dataset.stackIdentifier).style.display = 'block'; | ||
| 23 | |||
| 24 | } | ||
| 25 | |||
| 50 | 
This checks looks for references to variables that have not been declared. This is most likey a typographical error or a variable has been renamed.
To learn more about declaring variables in Javascript, see the MDN.