Worker Definition

import api from 'webpack-worker/api'

// initialization arguments can be passed from the client
api(url => {
  // perform any async initialization required by returning a promise
  fetch(url)
    .then(response => response.text())
    .then(text => {
      var data = parseFile(text)

      // at the end of the promise chain, return the api we want to expose
      return {
        topTenMovers: filter => {
          var filteredData = filterData(data, filter)
          var stocks = aggregateStocks(filteredData)
          var topTen = findTopTen(stocks)
          return mapToVectors(topTen)
        },
        // add other API functions here
      }
    })
  }
)