fix(app): render consecutive updates to position from props

[hwkerr]

Fixes issue #65 where the board would not transition from the current position to the next positionFromProps if the previousPositionFromProps and next positionFromProps represented identical board positions.

Previously, getDerivedStateFromProps in ./src/Chessboard/index.js would only update the board state if !isEqual(positionFromProps, currentPosition) && !isEqual(positionFromProps, previousPositionFromProps)

To help me better understand what was happening, I came up with these indexes to represent the different position instances used in the above conditional:

• i: currentPosition (the position that is still being displayed until the next render)
• i+1: positionFromProps (the position that is up next to be rendered)
• i-1: previousPositionFromProps (the positionFromProps from before currentPosition) The issue occurred when pos[i-1] was identical to pos[i+1].

To fix the issue, I removed !isEqual(positionFromProps, previousPositionFromProps) from the conditional.

[slig]

Thank you very much! This fixes the issue #35 as well which was fixed using a workaround.

[willb335]

@hwkerr Going to be sometime before I can publish this to npm. I lost my activation codes for npm and cannot log in and publish the package. Not sure if there is a way forward at this point. I'm in communication with GitHub at the moment to try to resolve this