diff --git a/package.json b/package.json
index ae25d1dc2..7ddd3cac7 100644
--- a/package.json
+++ b/package.json
@@ -75,6 +75,7 @@
     "@babel/polyfill": "^7.2.5",
     "@babel/preset-env": "^7.3.4",
     "@babel/preset-typescript": "^7.3.3",
+    "@types/jest": "^24.0.11",
     "@vant/doc": "^1.0.23",
     "@vant/eslint-config": "^1.1.2",
     "@vant/markdown-loader": "^1.0.3",
diff --git a/test/demo-test.js b/test/demo-test.ts
similarity index 92%
rename from test/demo-test.js
rename to test/demo-test.ts
index 348e3bb9f..480049c42 100644
--- a/test/demo-test.js
+++ b/test/demo-test.ts
@@ -7,10 +7,11 @@ const empty = {
   template: '<div><slot></slot></div>',
   inheritAttrs: false
 };
+
 Vue.component('demo-block', empty);
 Vue.component('demo-section', empty);
 
-export default function (Demo) {
+export default function (Demo: any) {
   test('renders demo correctly', () => {
     if (Demo.i18n) {
       Locale.add(Demo.i18n);
diff --git a/test/utils.js b/test/utils.ts
similarity index 56%
rename from test/utils.js
rename to test/utils.ts
index e5d0d6850..a779403ab 100644
--- a/test/utils.js
+++ b/test/utils.ts
@@ -1,14 +1,12 @@
 import Vue from 'vue';
-import { mount, TransitionStub } from '@vue/test-utils';
+import { mount, TransitionStub, Wrapper } from '@vue/test-utils';
 
 // prevent vue warning log
 Vue.config.silent = true;
 
-export {
-  mount
-};
+export { mount };
 
-function getTouch(el, x, y) {
+function getTouch(el: HTMLElement, x: number, y: number) {
   return {
     identifier: Date.now(),
     target: el,
@@ -24,8 +22,14 @@ function getTouch(el, x, y) {
 }
 
 // Trigger pointer/touch event
-export function trigger(wrapper, eventName, x = 0, y = 0, options = {}) {
-  const el = wrapper.element ? wrapper.element : wrapper;
+export function trigger(
+  wrapper: Wrapper<Vue> | HTMLElement,
+  eventName: string,
+  x: number = 0,
+  y: number = 0,
+  options: any = {}
+) {
+  const el = 'element' in wrapper ? wrapper.element : wrapper;
   const touchList = options.touchList || [getTouch(el, x, y)];
 
   if (options.x || options.y) {
@@ -34,17 +38,20 @@ export function trigger(wrapper, eventName, x = 0, y = 0, options = {}) {
 
   const event = document.createEvent('CustomEvent');
   event.initCustomEvent(eventName, true, true, {});
-  event.touches = touchList;
-  event.targetTouches = touchList;
-  event.changedTouches = touchList;
-  event.clientX = x;
-  event.clientY = y;
+
+  Object.assign(event, {
+    clientX: x,
+    clientY: y,
+    touches: touchList,
+    targetTouches: touchList,
+    changedTouches: touchList
+  });
 
   el.dispatchEvent(event);
 }
 
 // simulate drag gesture
-export function triggerDrag(el, x = 0, y = 0) {
+export function triggerDrag(el: Wrapper<Vue> | HTMLElement, x = 0, y = 0): void {
   trigger(el, 'touchstart', 0, 0);
   trigger(el, 'touchmove', x / 4, y / 4);
   trigger(el, 'touchmove', x / 3, y / 3);
@@ -54,12 +61,12 @@ export function triggerDrag(el, x = 0, y = 0) {
 }
 
 // promisify setTimeout
-export function later(delay) {
+export function later(delay: number = 0): Promise<void> {
   return new Promise(resolve => {
     setTimeout(resolve, delay);
   });
 }
 
-export function transitionStub() {
-  Vue.component('transition', TransitionStub);
+export function transitionStub(): void {
+  Vue.component('transition', TransitionStub as any);
 }
diff --git a/yarn.lock b/yarn.lock
index 18bbf77d6..9906b8d79 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -910,6 +910,18 @@
   resolved "https://registry.yarnpkg.com/@types/istanbul-lib-coverage/-/istanbul-lib-coverage-1.1.0.tgz#2cc2ca41051498382b43157c8227fea60363f94a"
   integrity sha512-ohkhb9LehJy+PA40rDtGAji61NCgdtKLAlFoYp4cnuuQEswwdK3vz9SOIkkyc3wrk8dzjphQApNs56yyXLStaQ==
 
+"@types/jest-diff@*":
+  version "20.0.1"
+  resolved "https://registry.yarnpkg.com/@types/jest-diff/-/jest-diff-20.0.1.tgz#35cc15b9c4f30a18ef21852e255fdb02f6d59b89"
+  integrity sha512-yALhelO3i0hqZwhjtcr6dYyaLoCHbAMshwtj6cGxTvHZAKXHsYGdff6E8EPw3xLKY0ELUTQ69Q1rQiJENnccMA==
+
+"@types/jest@^24.0.11":
+  version "24.0.11"
+  resolved "https://registry.yarnpkg.com/@types/jest/-/jest-24.0.11.tgz#1f099bea332c228ea6505a88159bfa86a5858340"
+  integrity sha512-2kLuPC5FDnWIDvaJBzsGTBQaBbnDweznicvK7UGYzlIJP4RJR2a4A/ByLUXEyEgag6jz8eHdlWExGDtH3EYUXQ==
+  dependencies:
+    "@types/jest-diff" "*"
+
 "@types/minimatch@*":
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/@types/minimatch/-/minimatch-3.0.3.tgz#3dca0e3f33b200fc7d1139c0cd96c1268cadfd9d"