Refactor to logical entities

[kurkle]

[kurkle]

Size Change: -127 B (-1%)

Total Size: 15.4 kB

Filename	Size	Change
dist/chartjs-plugin-zoom.esm.js	5.83 kB	-72 B (-1%)
dist/chartjs-plugin-zoom.js	6.09 kB	-76 B (-1%)
dist/chartjs-plugin-zoom.min.js	3.46 kB	+21 B (+1%)

[kurkle]

I'll try something to get a better diff, this is a huge review.

Edit: does not look like I can get git to detect moved functions.

[jledentu]

Awesome refactoring! 👏

I've found an issue in the zoom-time sample. The chart disappears when dragging, and there are console errors:

Uncaught TypeError: chartInstance.$zoom._options is undefined
    beforeDatasetsDraw http://127.0.0.1:8080/dist/chartjs-plugin-zoom.js:688
    callback http://127.0.0.1:8080/node_modules/chart.js/dist/chart.js:796
    ...

[kurkle]

Thanks @jledentu, did not go through the samples myself. I had not completed the beforeDatasetsDraw hook refactoring.
Completed that and finalized var => let/const changes.

[jledentu]

Looks good to me, congrats