gridsort | A stable adaptive partitioning comparison sort | Data Visualization library

I have incoming data from my CMS that all contains the value featuredProject, it can be true, null or false. If it's true I add a css class that makes it span across the screen. To help keep my grid structure intact I need to always have at least two projects with featuredProject set to false or null before or after a project with featuredProject set to true.

The problem is that the data from the CMS doesn't respect the supposed design of the grid and can and probably will come out distorted from what I need to loop it out correctly.

What I've been trying to achive now is a function that loops over all projects in the array from the CMS and looks at what the featuredProject value is on the current project in the loop. If it's set to true I look back at the past 2 indexes of the array to see what their featuredProject value is. If both of them doesn't have the value set to false or null I want to sort the array by shifting the current index one step forward, exit the loop and then loop over it again to check if all the values are in order.

Right now I get an error where one value of the array is undefined which I don't really get why.

An image displaying the grid I would like to achieve. https://imgur.com/a/KrdwlNI

The code I have right now.

The function to move an index