Handle invalid SDK key

Author: mikechu-optimizely

src/client/client.js

@@ -36,12 +36,10 @@ document.addEventListener("readystatechange", () => {
  payloadSizeDisplay.textContent = "{measure and fill json size in KB}";
  dataFileContentDisplay.textContent = "{fill json}";
 });
-
 manualPullButton.addEventListener("click", e => {
  e.preventDefault();
  socket.emit("datafile-pull", sdkKey, socketId);
 });
-
 sdkKeyField.addEventListener("change", e => {
  console.log("Ignoring SDK", sdkKey);
  socket.emit("ignoring-sdk-key", sdkKey);
@@ -61,15 +59,13 @@ const updatePayloadSize = obj => {
 
  payloadSizeDisplay.textContent = `${kb} KB`;
 };
-
 const updateJsonDisplay = obj => {
  const cleaned = JSON.stringify(obj, null, 2);
 
  dataFileContentDisplay.textContent = cleaned.replace(/^[\t ]*"[^:\n\r]+(?<!\\)":/gm, function (match) {
  return match.replace(/"/g, "");
  });
 };
-
 const getSizeInBytes = obj => {
  let str;
  if (typeof obj === 'string') {

src/server/server.js

@@ -19,7 +19,15 @@ const io = require("socket.io")(serverPort, {
 const fs = require('fs');
 const readDataFileFromDisk = sdkKey => {
  console.log("Reading datafile from disk", sdkKey);
- return JSON.parse(fs.readFileSync(`./datafiles/${sdkKey}.json`).toString());
+ const path = `./datafiles/${sdkKey}.json`;
+ if (!fs.existsSync(path)) {
+ return;
+ }
+ const buffer = fs.readFileSync(path);
+ if (!buffer) {
+ return;
+ }
+ return JSON.parse(buffer.toString());
 };
 
 const sendDataFile = (dataFile, toClientId, toAllClientsWithSdkKey) => {
@@ -49,7 +57,11 @@ io.on("connection", s => {
  if (isNullOrWhitespace(sdkKey)) {
  return;
  }
- sendDataFile(readDataFileFromDisk(sdkKey), socketId, null);
+ const dataFile =readDataFileFromDisk(sdkKey);
+ if (!dataFile) {
+ return;
+ }
+ sendDataFile(dataFile, socketId, null);
  });
 });