Incorporate feedback from Osmose.

Created a 'utils.js' file that is imported into the content script 'product_info.js'. These are now bundled by webpack into a single script.

.eslintignore

@@ -1 +1,2 @@
 build
+src/product_info.js

src/manifest.json

@@ -23,7 +23,7 @@
   "content_scripts": [
     {
       "matches": ["<all_urls>"],
-      "js": ["product_info.js"]
+      "js": ["product_info.bundle.js"]
     }
   ],
   "sidebar_action": {

src/product_info.js

@@ -1,66 +1,55 @@
+import utils from './utils';
+
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-const OpenGraphPropertyValues = {
-  title: 'og:title',
-  image: 'og:image',
-  price: 'og:price:amount',
-};
+(async function main() {
+  const OpenGraphPropertyValues = {
+    title: 'og:title',
+    image: 'og:image',
+    price: 'og:price:amount',
+  };
 
-function openBackgroundPort() {
-  return new Promise((resolve, reject) => {
-    const port = browser.runtime.connect();
-    port.onMessage.addListener((message) => {
-      if (message.type === 'background-ready') {
-        resolve(port);
+  function openBackgroundPort() {
+    return new Promise((resolve, reject) => {
+      const port = browser.runtime.connect();
+      port.onMessage.addListener((message) => {
+        if (message.type === 'background-ready') {
+          resolve(port);
+        }
+      });
+      port.onDisconnect.addListener(() => {
+        reject();
+      });
+    });
+  }
+
+  function getProductData(port) {
+    const data = {};
+    for (const [key, value] of Object.entries(OpenGraphPropertyValues)) {
+      const metaEle = document.querySelector(`meta[property="${value}"]`);
+      if (metaEle) {
+        data[key] = metaEle.getAttribute('content');
       }
-    });
-    port.onDisconnect.addListener(() => {
-      reject();
-    });
-  });
-}
-
-function getProductData(port) {
-  const data = {};
-  for (const [key, value] of Object.entries(OpenGraphPropertyValues)) {
-    const metaEle = document.querySelector(`meta[property="${value}"]`);
-    if (metaEle) {
-      data[key] = metaEle.getAttribute('content');
     }
-  }
-  port.postMessage({
-    type: 'product-data',
-    data,
-  });
-}
-
-function portSuccess(port) {
-  // Make sure page has finished loading, as JS could alter the DOM.
-  if (document.readyState === 'complete') {
-    getProductData(port);
-  } else {
-    window.addEventListener('load', () => {
-      getProductData(port);
+    port.postMessage({
+      type: 'product-data',
+      data,
     });
   }
-}
 
-let delay = 2; // seconds
-const DELAY_MULTIPLIER = 2;
-const NUM_ATTEMPTS = 5;
-const DELAY_MAX = delay ** NUM_ATTEMPTS;
-// Connect to the background script until it's available. See Issue #17 and bug 1474727.
-function portFail() {
-  if (delay > DELAY_MAX) {
-    console.error(`Could not establish a connection after ${NUM_ATTEMPTS} attempts.`);
-    return;
+  try {
+    const port = await utils.retry(openBackgroundPort);
+    // Make sure page has finished loading, as JS could alter the DOM.
+    if (document.readyState === 'complete') {
+      getProductData(port);
+    } else {
+      window.addEventListener('load', () => {
+        getProductData(port);
+      });
+    }
+  } catch (err) {
+    console.error('Could not establish connection to background script.');
   }
-  setTimeout(() => {
-    openBackgroundPort().then(portSuccess, portFail);
-    delay *= DELAY_MULTIPLIER;
-  }, delay * 1000); // ms
-}
-
-openBackgroundPort().then(portSuccess, portFail);
+}());

src/utils.js

@@ -0,0 +1,33 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+const utils = {
+  /* eslint-disable arrow-body-style */
+  wait: async (delay) => {
+    return new Promise((resolve) => {
+      window.setTimeout(resolve, delay);
+    });
+  },
+
+  retry: async (callback, maxRetries = 5, delayFactor = 2, initialDelay = 2) => {
+    /* eslint-disable no-await-in-loop */
+    let delay = initialDelay;
+    let lastError = null;
+    for (let k = 0; k < maxRetries; k++) {
+      try {
+        // If we don't await here, the callback's promise will be returned
+        // immediately instead of potentially failing.
+        return await callback();
+      } catch (err) {
+        lastError = err;
+        await utils.wait(delay);
+        delay *= delayFactor;
+      }
+    }
+    throw lastError;
+  },
+};
+
+export default utils;

webpack.config.js

@@ -13,6 +13,7 @@ module.exports = {
   entry: {
     background: './src/background.js',
     sidebar: './src/sidebar.jsx',
+    product_info: './src/product_info.js',
   },
   output: {
     path: BUILD_DIR,
@@ -31,8 +32,6 @@ module.exports = {
   },
   plugins: [
     new CopyWebpackPlugin([
-      {from: 'product_info.js'},
-
       // Static files
       {from: '**/*.svg'},
       {from: '**/*.html'},