d3-force WebWorker layout

d3-force-webworker-layout.js

function runLayout(graph) {
  return new Promise(resolve => {
    const workerCode = `
      importScripts('https://unpkg.com/d3@5.14.2/dist/d3.min.js');

      function runLayout(graph) {
        const { nodes, links } = graph;

        d3.forceSimulation(nodes)
          .force('link', d3.forceLink(links).id(d => d.id))
          .force('charge', d3.forceManyBody().strength(-250))
          .force('center', d3.forceCenter())
          .stop()
          .tick(300);

        const positions = Object.fromEntries(nodes.map(node => {
          return [node.id, { x: node.x, y: node.y }];
        }));

        return positions;
      }

      self.onmessage = event => {
        const graph = event.data;
        const result = runLayout(graph);
        self.postMessage(result);
      }
    `;
    const workerBlob = new Blob([workerCode], {
      type: 'application/javascript'
    });
    const workerUrl = URL.createObjectURL(workerBlob)
    const worker = new Worker(workerUrl);

    worker.onmessage = event => {
      resolve(event.data);
      worker.terminate();
      URL.revokeObjectURL(workerUrl);                 
    };
    worker.postMessage(graph);
  });
}