simplify

Author: mbostock

test/plots/stocks-index.js

@@ -8,14 +8,9 @@ function formatChange(x) {
 }
 
 export default async function() {
-  const [aapl, amzn, goog, ibm] = await Promise.all([
-    d3.csv("data/aapl.csv", d3.autoType),
-    d3.csv("data/amzn.csv", d3.autoType),
-    d3.csv("data/goog.csv", d3.autoType),
-    d3.csv("data/ibm.csv", d3.autoType)
-  ]);
-  const stocks = [["AAPL", aapl], ["AMZN", amzn], ["GOOG", goog], ["IBM", ibm]]
-    .flatMap(([symbol, data]) => {
+  const stocks = (await Promise.all(["aapl", "amzn", "goog", "ibm"].map(async symbol => {
+      return [symbol.toUpperCase(), await d3.csv(`data/${symbol}.csv`, d3.autoType)];
+    }))).flatMap(([symbol, data]) => {
       const [{Close: basis}] = data;
       return data.map(({Date, Close}) => ({
         symbol,