diff --git a/integration_test/functions/src/auth-tests.ts b/integration_test/functions/src/auth-tests.ts
index aaef21e6a..2c1e1d4e6 100644
--- a/integration_test/functions/src/auth-tests.ts
+++ b/integration_test/functions/src/auth-tests.ts
@@ -1,10 +1,10 @@
-import * as functions from 'firebase-functions';
-import { TestSuite, expectEq } from './testing';
 import * as admin from 'firebase-admin';
+import * as functions from 'firebase-functions';
+import { expectEq, TestSuite } from './testing';
 import UserMetadata = admin.auth.UserRecord;
 
 export const createUserTests: any = functions.auth.user().onCreate((u, c) => {
-  let testId: string = u.displayName;
+  const testId: string = u.displayName;
   console.log(`testId is ${testId}`);
 
   return new TestSuite<UserMetadata>('auth user onCreate')
@@ -38,7 +38,7 @@ export const createUserTests: any = functions.auth.user().onCreate((u, c) => {
 });
 
 export const deleteUserTests: any = functions.auth.user().onDelete((u, c) => {
-  let testId: string = u.displayName;
+  const testId: string = u.displayName;
   console.log(`testId is ${testId}`);
 
   return new TestSuite<UserMetadata>('auth user onDelete')
diff --git a/integration_test/functions/src/database-tests.ts b/integration_test/functions/src/database-tests.ts
index 215e6bd3b..de3030d3a 100644
--- a/integration_test/functions/src/database-tests.ts
+++ b/integration_test/functions/src/database-tests.ts
@@ -1,6 +1,6 @@
-import * as functions from 'firebase-functions';
-import { TestSuite, expectEq, expectMatches } from './testing';
 import * as admin from 'firebase-admin';
+import * as functions from 'firebase-functions';
+import { expectEq, expectMatches, TestSuite } from './testing';
 import DataSnapshot = admin.database.DataSnapshot;
 
 const testIdFieldName = 'testId';
diff --git a/integration_test/functions/src/firestore-tests.ts b/integration_test/functions/src/firestore-tests.ts
index e5f8acdbf..49d1ae919 100644
--- a/integration_test/functions/src/firestore-tests.ts
+++ b/integration_test/functions/src/firestore-tests.ts
@@ -1,6 +1,6 @@
-import * as functions from 'firebase-functions';
-import { TestSuite, expectEq, expectDeepEq } from './testing';
 import * as admin from 'firebase-admin';
+import * as functions from 'firebase-functions';
+import { expectDeepEq, expectEq, TestSuite } from './testing';
 import DocumentSnapshot = admin.firestore.DocumentSnapshot;
 
 const testIdFieldName = 'documentId';
diff --git a/integration_test/functions/src/https-tests.ts b/integration_test/functions/src/https-tests.ts
index 7a0889ef6..55c7df983 100644
--- a/integration_test/functions/src/https-tests.ts
+++ b/integration_test/functions/src/https-tests.ts
@@ -1,6 +1,6 @@
 import * as functions from 'firebase-functions';
 import * as _ from 'lodash';
-import { TestSuite, expectEq } from './testing';
+import { expectEq, TestSuite } from './testing';
 
 export const callableTests: any = functions.https.onCall((d) => {
   return new TestSuite('https onCall')
diff --git a/integration_test/functions/src/index.ts b/integration_test/functions/src/index.ts
index 967b3d376..05f9e2035 100644
--- a/integration_test/functions/src/index.ts
+++ b/integration_test/functions/src/index.ts
@@ -1,11 +1,8 @@
-import * as functions from 'firebase-functions';
-import * as https from 'https';
-import * as admin from 'firebase-admin';
 import { Request, Response } from 'express';
+import * as admin from 'firebase-admin';
+import * as functions from 'firebase-functions';
 import * as fs from 'fs';
-
-import * as PubSub from '@google-cloud/pubsub';
-const pubsub = PubSub();
+import * as https from 'https';
 
 export * from './pubsub-tests';
 export * from './database-tests';
@@ -82,7 +79,7 @@ export const integrationTests: any = functions
       .split('.')
       .slice(1)
       .join('.');
-    let pubsub: any = require('@google-cloud/pubsub')();
+    const pubsub: any = require('@google-cloud/pubsub')();
     const testId = admin
       .database()
       .ref()
@@ -155,7 +152,7 @@ export const integrationTests: any = functions
       .then(() => {
         // On test completion, check that all tests pass and reply "PASS", or provide further details.
         console.log('Waiting for all tests to report they pass...');
-        let ref = admin.database().ref(`testRuns/${testId}`);
+        const ref = admin.database().ref(`testRuns/${testId}`);
         return new Promise((resolve, reject) => {
           let testsExecuted = 0;
           ref.on('child_added', (snapshot) => {
diff --git a/integration_test/functions/src/pubsub-tests.ts b/integration_test/functions/src/pubsub-tests.ts
index ebac609dc..3c1b1ecc7 100644
--- a/integration_test/functions/src/pubsub-tests.ts
+++ b/integration_test/functions/src/pubsub-tests.ts
@@ -1,6 +1,6 @@
-import * as functions from 'firebase-functions';
 import * as admin from 'firebase-admin';
-import { TestSuite, expectEq, evaluate, success } from './testing';
+import * as functions from 'firebase-functions';
+import { evaluate, expectEq, success, TestSuite } from './testing';
 import PubsubMessage = functions.pubsub.Message;
 
 // TODO(inlined) use multiple queues to run inline.
@@ -64,7 +64,7 @@ export const schedule: any = functions.pubsub
   // For the test, the job is triggered by the jobs:run api
   .onRun((context) => {
     let testId;
-    let db = admin.database();
+    const db = admin.database();
     return new Promise(async (resolve, reject) => {
       await db
         .ref('testRuns')
diff --git a/integration_test/functions/src/remoteConfig-tests.ts b/integration_test/functions/src/remoteConfig-tests.ts
index 2b824fbbd..3474e1fc2 100644
--- a/integration_test/functions/src/remoteConfig-tests.ts
+++ b/integration_test/functions/src/remoteConfig-tests.ts
@@ -1,5 +1,5 @@
 import * as functions from 'firebase-functions';
-import { TestSuite, expectEq } from './testing';
+import { expectEq, TestSuite } from './testing';
 import TemplateVersion = functions.remoteConfig.TemplateVersion;
 
 export const remoteConfigTests: any = functions.remoteConfig.onUpdate(
diff --git a/integration_test/functions/src/storage-tests.ts b/integration_test/functions/src/storage-tests.ts
index 7ced40fc9..43cdef5e2 100644
--- a/integration_test/functions/src/storage-tests.ts
+++ b/integration_test/functions/src/storage-tests.ts
@@ -1,7 +1,6 @@
 import * as functions from 'firebase-functions';
-import { TestSuite, expectEq, expectDeepEq } from './testing';
+import { expectEq, TestSuite } from './testing';
 import ObjectMetadata = functions.storage.ObjectMetadata;
-const testIdFieldName = 'documentId';
 
 export const storageTests: any = functions
   .runWith({
diff --git a/integration_test/functions/src/testing.ts b/integration_test/functions/src/testing.ts
index d3782a981..43d3e69d5 100644
--- a/integration_test/functions/src/testing.ts
+++ b/integration_test/functions/src/testing.ts
@@ -1,9 +1,11 @@
 import * as firebase from 'firebase-admin';
-import * as _ from 'lodash';
 import { EventContext } from 'firebase-functions';
+import * as _ from 'lodash';
 
 export type TestCase<T> = (data: T, context?: EventContext) => any;
-export type TestCaseMap<T> = { [key: string]: TestCase<T> };
+export interface TestCaseMap<T> {
+  [key: string]: TestCase<T>;
+}
 
 export class TestSuite<T> {
   private name: string;
@@ -20,8 +22,8 @@ export class TestSuite<T> {
   }
 
   run(testId: string, data: T, context?: EventContext): Promise<any> {
-    let running: Array<Promise<any>> = [];
-    for (let testName in this.tests) {
+    const running: Array<Promise<any>> = [];
+    for (const testName in this.tests) {
       if (!this.tests.hasOwnProperty(testName)) {
         continue;
       }
@@ -36,7 +38,7 @@ export class TestSuite<T> {
           },
           (error) => {
             console.error(`Failed: ${testName}`, error);
-            return { name: testName, passed: 0, error: error };
+            return { name: testName, passed: 0, error };
           }
         );
       running.push(run);
diff --git a/tsconfig.json b/tsconfig.json
index 2f7cc7e0d..6538f1f07 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,5 +4,5 @@
     "sourceMap": true
   },
   "extends": "./tsconfig.release.json",
-  "include": ["./src/**/*.ts", "./spec/**/*.ts"]
+  "include": ["**/*.ts"]
 }