Updated select samples to use async/await. (#1012)

* Updated select samples to use async/await.

* Minor fixes.

* Minor fixes.

* Completed requested changes.

Author: chenyumic

appengine/analytics/app.js

@@ -50,19 +50,25 @@ function trackEvent(category, action, label, value) {
   return got.post('http://www.google-analytics.com/collect', data);
 }
 
-app.get('/', (req, res, next) => {
+app.get('/', async (req, res, next) => {
   // Event value must be numeric.
-  trackEvent('Example category', 'Example action', 'Example label', '100')
-    .then(() => {
-      res
-        .status(200)
-        .send('Event tracked.')
-        .end();
-    })
+  try {
+    await trackEvent(
+      'Example category',
+      'Example action',
+      'Example label',
+      '100'
+    );
+    res
+      .status(200)
+      .send('Event tracked.')
+      .end();
+  } catch (error) {
     // This sample treats an event tracking error as a fatal error. Depending
     // on your application's needs, failing to track an event may not be
     // considered an error.
-    .catch(next);
+    next(error);
+  }
 });
 
 const PORT = process.env.PORT || 8080;

appengine/datastore/app.js

@@ -53,15 +53,10 @@ function getVisits() {
     .order('timestamp', {descending: true})
     .limit(10);
 
-  return datastore.runQuery(query).then(results => {
-    const entities = results[0];
-    return entities.map(
-      entity => `Time: ${entity.timestamp}, AddrHash: ${entity.userIp}`
-    );
-  });
+  return datastore.runQuery(query);
 }
 
-app.get('/', (req, res, next) => {
+app.get('/', async (req, res, next) => {
   // Create a visit record to be stored in the database
   const visit = {
     timestamp: new Date(),
@@ -73,17 +68,21 @@ app.get('/', (req, res, next) => {
       .substr(0, 7),
   };
 
-  insertVisit(visit)
-    // Query the last 10 visits from Datastore.
-    .then(() => getVisits())
-    .then(visits => {
-      res
-        .status(200)
-        .set('Content-Type', 'text/plain')
-        .send(`Last 10 visits:\n${visits.join('\n')}`)
-        .end();
-    })
-    .catch(next);
+  try {
+    await insertVisit(visit);
+    const results = await getVisits();
+    const entities = results[0];
+    const visits = entities.map(
+      entity => `Time: ${entity.timestamp}, AddrHash: ${entity.userIp}`
+    );
+    res
+      .status(200)
+      .set('Content-Type', 'text/plain')
+      .send(`Last 10 visits:\n${visits.join('\n')}`)
+      .end();
+  } catch (error) {
+    next(error);
+  }
 });
 
 const PORT = process.env.PORT || 8080;

appengine/metadata/standard/server.js

@@ -31,26 +31,23 @@ function getProjectId() {
     },
   };
 
-  return request(METADATA_PROJECT_ID_URL, options)
-    .then(response => response.body)
-    .catch(err => {
-      if (err && err.statusCode !== 200) {
-        console.log('Error while talking to metadata server.');
-        return 'Unknown_Project_ID';
-      }
-      return Promise.reject(err);
-    });
+  return request(METADATA_PROJECT_ID_URL, options);
 }
 
-app.get('/', (req, res, next) => {
-  getProjectId()
-    .then(projectId => {
-      res
-        .status(200)
-        .send(`Project ID: ${projectId}`)
-        .end();
-    })
-    .catch(next);
+app.get('/', async (req, res, next) => {
+  try {
+    let response = await getProjectId();
+    let projectId = response.body;
+    res
+      .status(200)
+      .send(`Project ID: ${projectId}`)
+      .end();
+  } catch (error) {
+    if (error && error.statusCode && error.statusCode !== 200) {
+      console.log('Error while talking to metadata server.');
+    }
+    next(error);
+  }
 });
 
 const PORT = process.env.PORT || 8080;

appengine/pubsub/app.js

@@ -44,28 +44,28 @@ const messages = [];
 // The following environment variables are set by app.yaml when running on GAE,
 // but will need to be manually set when running locally.
 const PUBSUB_VERIFICATION_TOKEN = process.env.PUBSUB_VERIFICATION_TOKEN;
+const TOPIC = process.env.PUBSUB_TOPIC;
 
-const topic = pubsub.topic(process.env.PUBSUB_TOPIC);
-const publisher = topic.publisher();
+const publisher = pubsub.topic(TOPIC).publisher();
 
 // [START gae_flex_pubsub_index]
 app.get('/', (req, res) => {
   res.render('index', {messages: messages});
 });
 
-app.post('/', formBodyParser, (req, res, next) => {
+app.post('/', formBodyParser, async (req, res, next) => {
   if (!req.body.payload) {
     res.status(400).send('Missing payload');
     return;
   }
 
-  publisher.publish(Buffer.from(req.body.payload), err => {
-    if (err) {
-      next(err);
-      return;
-    }
-    res.status(200).send('Message sent');
-  });
+  let data = Buffer.from(req.body.payload);
+  try {
+    let messageId = await publisher.publish(data);
+    res.status(200).send(`Message ${messageId} sent.`);
+  } catch (error) {
+    next(error);
+  }
 });
 // [END gae_flex_pubsub_index]
 

appengine/pubsub/app.standard.yaml

@@ -1,3 +1,4 @@
+
 # Copyright 2015-2016, Google, Inc.
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.

appengine/pubsub/test/app.test.js

@@ -35,7 +35,7 @@ test.serial.cb(`should send a message to Pub/Sub`, t => {
     .send({payload: payload})
     .expect(200)
     .expect(response => {
-      t.is(response.text, `Message sent`);
+      t.regex(response.text, /Message \d* sent/);
     })
     .end(t.end);
 });