Snap to grid in reshapable?

just like the following snapping, is there any snapping possible to reshapable? also how to change the shapes of the diamonds at the corner?
resizeCellSize: new go.Size(14, 14)

Are you asking about customizing the LinkReshapingTool? The SnapLinkReshapingTool extension, demonstrated in https://gojs.net/latest/extensions/SnapLinkReshaping.html, does exactly what I think you are asking for. Note the code in the computeReshape method.

If you are asking about customizing the GeometryReshapingTool, override its computeReshape method to return a Point on the grid – call Point.snapToGridPoint.