diff --git a/functions/pubsub/index.js b/functions/pubsub/index.js
index 03ce246b3f..f2f5916205 100644
--- a/functions/pubsub/index.js
+++ b/functions/pubsub/index.js
@@ -39,23 +39,12 @@ const {Buffer} = require('safe-buffer');
  * @param {string} req.body.message Message to publish.
  * @param {object} res Cloud Function response context.
  */
-exports.publish = (req, res) => {
-  if (!req.body.topic) {
+exports.publish = async (req, res) => {
+  if (!req.body.topic || !req.body.message) {
     res
       .status(500)
       .send(
-        new Error(
-          'Topic not provided. Make sure you have a "topic" property in your request'
-        )
-      );
-    return;
-  } else if (!req.body.message) {
-    res
-      .status(500)
-      .send(
-        new Error(
-          'Message not provided. Make sure you have a "message" property in your request'
-        )
+        'Missing parameter(s); include "topic" and "subscription" properties in your request.'
       );
     return;
   }
@@ -65,21 +54,22 @@ exports.publish = (req, res) => {
   // References an existing topic
   const topic = pubsub.topic(req.body.topic);
 
-  const message = {
+  const messageObject = {
     data: {
       message: req.body.message,
     },
   };
+  const messageBuffer = Buffer.from(JSON.stringify(messageObject), 'base64');
 
   // Publishes a message
-  return topic
-    .publish(message)
-    .then(() => res.status(200).send('Message published.'))
-    .catch(err => {
-      console.error(err);
-      res.status(500).send(err);
-      return Promise.reject(err);
-    });
+  try {
+    await topic.publish(messageBuffer);
+    res.status(200).send('Message published.');
+  } catch (err) {
+    console.error(err);
+    res.status(500).send(err);
+    return Promise.reject(err);
+  }
 };
 // [END functions_pubsub_publish]
 
@@ -87,18 +77,11 @@ exports.publish = (req, res) => {
 /**
  * Triggered from a message on a Cloud Pub/Sub topic.
  *
- * @param {object} event The Cloud Functions event.
- * @param {object} event.data The Cloud Pub/Sub Message object.
- * @param {string} event.data.data The "data" property of the Cloud Pub/Sub Message.
- * @param {function} callback The callback function.
+ * @param {object} pubsubMessage The Cloud Pub/Sub Message object.
+ * @param {string} pubsubMessage.data The "data" property of the Cloud Pub/Sub Message.
  */
-exports.subscribe = (event, callback) => {
-  const pubsubMessage = event.data;
-
-  // We're just going to log the message to prove that it worked!
+exports.subscribe = pubsubMessage => {
+  // Print out the data from Pub/Sub, to prove that it worked
   console.log(Buffer.from(pubsubMessage.data, 'base64').toString());
-
-  // Don't forget to call the callback!
-  callback();
 };
 // [END functions_pubsub_subscribe]
diff --git a/functions/pubsub/package.json b/functions/pubsub/package.json
index 0232225f08..e624f72160 100644
--- a/functions/pubsub/package.json
+++ b/functions/pubsub/package.json
@@ -20,12 +20,16 @@
   },
   "devDependencies": {
     "@google-cloud/nodejs-repo-tools": "^3.3.0",
+    "child-process-promise": "^2.2.1",
     "mocha": "^6.0.0",
-    "proxyquire": "^2.1.0",
-    "sinon": "^7.2.7"
+    "request": "^2.88.0",
+    "requestretry": "^4.0.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
-    "requiresProjectId": true
+    "requiresProjectId": true,
+    "requiredEnvVars": [
+      "FUNCTIONS_TOPIC"
+    ]
   }
 }
diff --git a/functions/pubsub/test/index.test.js b/functions/pubsub/test/index.test.js
index a3e7678622..f708888646 100644
--- a/functions/pubsub/test/index.test.js
+++ b/functions/pubsub/test/index.test.js
@@ -15,134 +15,86 @@
 
 'use strict';
 
-const proxyquire = require('proxyquire').noCallThru();
-const sinon = require('sinon');
 const assert = require('assert');
 const tools = require('@google-cloud/nodejs-repo-tools');
 const {Buffer} = require('safe-buffer');
+const path = require('path');
 
-const TOPIC = 'topic';
+const execPromise = require('child-process-promise').exec;
+const requestRetry = require('requestretry');
+
+const BASE_URL = process.env.BASE_URL || 'http://localhost:8080';
+const cwd = path.join(__dirname, '..');
+
+const TOPIC = process.env.FUNCTIONS_TOPIC;
 const MESSAGE = 'Hello, world!';
 
-function getSample() {
-  const topicMock = {
-    publish: sinon.stub().returns(Promise.resolve()),
-  };
-  const pubsubMock = {
-    topic: sinon.stub().returns(topicMock),
-  };
-  const PubSubMock = sinon.stub().returns(pubsubMock);
-
-  return {
-    program: proxyquire('../', {
-      '@google-cloud/pubsub': {PubSub: PubSubMock},
-    }),
-    mocks: {
-      PubSub: PubSubMock,
-      pubsub: pubsubMock,
-      topic: topicMock,
-      req: {
-        body: {
-          topic: TOPIC,
-          message: MESSAGE,
-        },
-      },
-      res: {
-        status: sinon.stub().returnsThis(),
-        send: sinon.stub().returnsThis(),
+describe('functions/pubsub', () => {
+  beforeEach(tools.stubConsole);
+  afterEach(tools.restoreConsole);
+
+  let ffProc;
+
+  before(() => {
+    ffProc = execPromise(
+      `functions-framework --target=publish --signature-type=http`,
+      {timeout: 1000, shell: true, cwd}
+    );
+  });
+
+  after(async () => {
+    try {
+      await ffProc;
+    } catch (err) {
+      // Timeouts always cause errors on Linux, so catch them
+      if (err.name && err.name === 'ChildProcessError') {
+        return;
+      }
+
+      throw err;
+    }
+  });
+
+  it('publish fails without parameters', async () => {
+    const response = await requestRetry({
+      url: `${BASE_URL}/`,
+      method: 'POST',
+      body: {},
+      retryDelay: 200,
+      json: true,
+    });
+
+    assert.strictEqual(response.statusCode, 500);
+    assert.strictEqual(
+      response.body,
+      'Missing parameter(s); include "topic" and "subscription" properties in your request.'
+    );
+  });
+
+  it('publishes a message', async () => {
+    const response = await requestRetry({
+      url: `${BASE_URL}/`,
+      method: 'POST',
+      body: {
+        topic: TOPIC,
+        message: 'Pub/Sub from Cloud Functions',
       },
-    },
-  };
-}
-
-beforeEach(tools.stubConsole);
-afterEach(tools.restoreConsole);
-
-it('Publish fails without a topic', () => {
-  const expectedMsg =
-    'Topic not provided. Make sure you have a "topic" property in your request';
-  const sample = getSample();
-
-  delete sample.mocks.req.body.topic;
-  sample.program.publish(sample.mocks.req, sample.mocks.res);
-
-  assert.strictEqual(sample.mocks.res.status.callCount, 1);
-  assert.deepStrictEqual(sample.mocks.res.status.firstCall.args, [500]);
-  assert.strictEqual(sample.mocks.res.send.callCount, 1);
-  assert.strictEqual(
-    sample.mocks.res.send.firstCall.args[0].message,
-    expectedMsg
-  );
-});
+      retryDelay: 200,
+      json: true,
+    });
 
-it('Publish fails without a message', () => {
-  const expectedMsg =
-    'Message not provided. Make sure you have a "message" property in your request';
-  const sample = getSample();
-
-  delete sample.mocks.req.body.message;
-  sample.program.publish(sample.mocks.req, sample.mocks.res);
-
-  assert.strictEqual(sample.mocks.res.status.callCount, 1);
-  assert.deepStrictEqual(sample.mocks.res.status.firstCall.args, [500]);
-  assert.strictEqual(sample.mocks.res.send.callCount, 1);
-  assert.strictEqual(
-    sample.mocks.res.send.firstCall.args[0].message,
-    expectedMsg
-  );
-});
+    assert.strictEqual(response.statusCode, 200);
+    assert.strictEqual(response.body, 'Message published.');
+  });
 
-it('Publishes the message to the topic and calls success', async () => {
-  const expectedMsg = 'Message published.';
-  const sample = getSample();
+  it('prints out a message', () => {
+    const jsonObject = JSON.stringify({data: MESSAGE});
+    const jsonBuffer = Buffer.from(jsonObject).toString('base64');
+    const pubsubMessage = {data: jsonBuffer, attributes: {}};
 
-  await sample.program.publish(sample.mocks.req, sample.mocks.res);
-  assert.strictEqual(sample.mocks.topic.publish.callCount, 1);
-  assert.deepStrictEqual(sample.mocks.topic.publish.firstCall.args, [
-    {
-      data: {
-        message: MESSAGE,
-      },
-    },
-  ]);
-  assert.strictEqual(sample.mocks.res.status.callCount, 1);
-  assert.deepStrictEqual(sample.mocks.res.status.firstCall.args, [200]);
-  assert.strictEqual(sample.mocks.res.send.callCount, 1);
-  assert.deepStrictEqual(sample.mocks.res.send.firstCall.args, [expectedMsg]);
-});
-
-it('Fails to publish the message and calls failure', async () => {
-  const error = new Error('error');
-  const sample = getSample();
-  sample.mocks.topic.publish.returns(Promise.reject(error));
-
-  try {
-    await sample.program.publish(sample.mocks.req, sample.mocks.res);
-  } catch (err) {
-    assert.deepStrictEqual(err, error);
-    assert.strictEqual(console.error.callCount, 1);
-    assert.deepStrictEqual(console.error.firstCall.args, [error]);
-    assert.strictEqual(sample.mocks.res.status.callCount, 1);
-    assert.deepStrictEqual(sample.mocks.res.status.firstCall.args, [500]);
-    assert.strictEqual(sample.mocks.res.send.callCount, 1);
-    assert.deepStrictEqual(sample.mocks.res.send.firstCall.args, [error]);
-  }
-});
+    require('..').subscribe(pubsubMessage);
 
-it('Subscribes to a message', () => {
-  const callback = sinon.stub();
-  const json = JSON.stringify({data: MESSAGE});
-  const event = {
-    data: {
-      data: Buffer.from(json).toString('base64'),
-    },
-  };
-
-  const sample = getSample();
-  sample.program.subscribe(event, callback);
-
-  assert.strictEqual(console.log.callCount, 1);
-  assert.deepStrictEqual(console.log.firstCall.args, [json]);
-  assert.strictEqual(callback.callCount, 1);
-  assert.deepStrictEqual(callback.firstCall.args, []);
+    assert.strictEqual(console.log.callCount, 1);
+    assert.deepStrictEqual(console.log.firstCall.args, [jsonObject]);
+  });
 });