npm install d3-bboxCollide
A bounding box constraint for forceSimulation.
Here's a data-driven example with 500 nodes.
You can include it as a "collide" constraint in your force simulation for rectangular nodes or bounding boxes around labels. It uses bounding boxes, which are [[],[]] arrays that give the top-left and bottom-right coordinates of a rectilinear space. You can set these bounding boxes manually or base them of the data of the node.
The following would set up a bounding box constraint for a 20x10 rectangle (remember the bounding box is around the center of your node, so the top left corner will be -10px for the x-coordinate and -5px for the y-coordinate while the bottom right corner of the bounding box will be 10px for the x-coordinate and 5px for the y-coordinate).
var rectangleCollide = bboxCollide([[-10,-5],[10,5]])
Which you would attach to your force like so:
var force = d3.forceSimulation(data)
.force("collide", rectangleCollide)