update typescript and fix test cases

package.json

@@ -53,7 +53,7 @@
     "ts-node": "^7.0.1",
     "tslib": "^1.9.3",
     "tslint": "^4.5.1",
-    "typescript": "^3.2.4"
+    "typescript": "^3.4.1"
   },
   "dependencies": {
     "@types/smoothscroll-polyfill": "^0.3.0",

test/integration.test.ts

@@ -2,9 +2,15 @@ import * as fs from 'fs';
 import * as path from 'path';
 import * as puppeteer from 'puppeteer';
 import { assertSnapshot } from './utils';
+import { Suite } from 'mocha';
 
-describe('record integration tests', () => {
+interface ISuite extends Suite {
-  function getHtml(fileName: string): string {
+  code: string;
+  browser: puppeteer.Browser;
+}
+
+describe('record integration tests', function(this: ISuite) {
+  const getHtml = (fileName: string): string => {
     const filePath = path.resolve(__dirname, `./html/${fileName}`);
     const html = fs.readFileSync(filePath, 'utf8');
     return html.replace(
@@ -24,7 +30,7 @@ describe('record integration tests', () => {
     </body>
     `,
     );
-  }
+  };
 
   before(async () => {
     this.browser = await puppeteer.launch({

test/record.test.ts

@@ -11,6 +11,14 @@ import {
   EventType,
 } from '../src/types';
 import { assertSnapshot } from './utils';
+import { Suite } from 'mocha';
+
+interface ISuite extends Suite {
+  code: string;
+  browser: puppeteer.Browser;
+  page: puppeteer.Page;
+  events: eventWithTime[];
+}
 
 interface IWindow extends Window {
   rrweb: {
@@ -19,7 +27,7 @@ interface IWindow extends Window {
   emit: (e: eventWithTime) => undefined;
 }
 
-describe('record', () => {
+describe('record', function(this: ISuite) {
   before(async () => {
     this.browser = await puppeteer.launch({
       headless: false,

test/replayer.test.ts

@@ -4,6 +4,7 @@ import * as fs from 'fs';
 import * as path from 'path';
 import * as puppeteer from 'puppeteer';
 import { expect } from 'chai';
+import { Suite } from 'mocha';
 import {
   EventType,
   eventWithTime,
@@ -113,7 +114,13 @@ interface IWindow extends Window {
   };
 }
 
-describe('replayer', () => {
+interface ISuite extends Suite {
+  code: string;
+  browser: puppeteer.Browser;
+  page: puppeteer.Page;
+}
+
+describe('replayer', function(this: ISuite) {
   before(async () => {
     this.browser = await puppeteer.launch({
       headless: false,