Tools for processing webpack output, to help identify time spent

factory.js

const input = require('./factory.json')

const addPaths = (name, prefix) => prefix === '' ? name : `${prefix}/${name}`

const createNode = (name, subPath) => {
  return {
    name,
    path: addPaths(name, subPath),
    cost: 0,
    children: []
  }
}

const getOrCreateChild = (tree, childName, subPath) => {
  const existingChild = tree.children.find(e => e.name === childName)

  if (existingChild) {
    return existingChild
  } else {
    const newChild = createNode(childName, subPath)
    tree.children.push(newChild)

    return newChild
  }
}
const mergePaths = (currentTree, modulePath, moduleSize, elems, subPath = '') => {
  if (elems.length === 0) { return currentTree }

  const elemHead = elems[0]
  const nodeForHead = getOrCreateChild(currentTree, elemHead, subPath)
  nodeForHead.cost = nodeForHead.cost + moduleSize

  if (elems.length === 1) {
    nodeForHead.module = modulePath
  }

  mergePaths(
    nodeForHead,
    modulePath,
    moduleSize,
    elems.slice(1),
    addPaths(elemHead, subPath))

  return currentTree
}

const rootNode = createNode('root')

const subset = input // .slice(0, 5)
const result = subset.reduce((currentTree, curr) => {
  const [modulePath, moduleSize] = curr
  const elems = modulePath.split('/')

  return mergePaths(currentTree, modulePath, moduleSize, elems)
}, rootNode)

const sortTree = (node) => {
  node.children.sort((a, b) => b.cost - a.cost)
  node.children.forEach(sortTree)
}
sortTree(result)

console.log(JSON.stringify(result, 0, 2))

jq_commands

# Initial pass of jq to trim down webpack output
jq '.modules | map([.name, .profile.factory])' stats.json > factory.json

# Create a tree summary
node factory.js > tree.json

# Once you have generated a tree summary
jq '.children[0].children[0].children[] | { name:.name, cost:.cost, path:.path }' tree.json