[build] add typescript compiler (#2697)

packages/utils/use/bem.ts

@@ -10,9 +10,9 @@
 const ELEMENT = '__';
 const MODS = '--';
 
-const join = (name, el, symbol) => (el ? name + symbol + el : name);
+const join = (name: string, el: string, symbol: string) => (el ? name + symbol + el : name);
 
-const prefix = (name, mods) => {
+const prefix = (name: string, mods: any): any => {
   if (typeof mods === 'string') {
     return join(name, mods, MODS);
   }
@@ -21,7 +21,7 @@ const prefix = (name, mods) => {
     return mods.map(item => prefix(name, item));
   }
 
-  const ret = {};
+  const ret: { [key: string]: any } = {};
   if (mods) {
     Object.keys(mods).forEach(key => {
       ret[name + MODS + key] = mods[key];
@@ -31,7 +31,7 @@ const prefix = (name, mods) => {
   return ret;
 };
 
-export default name => (el, mods) => {
+export default (name: string) => (el: any, mods?: any) => {
   if (el && typeof el !== 'string') {
     mods = el;
     el = '';

packages/utils/use/i18n.ts

@@ -1,9 +1,9 @@
 import { get, camelize } from '..';
 import { lang, messages } from '../../locale';
 
-export default name => {
+export default (name: string) => {
   const prefix = camelize(name) + '.';
-  return (path, ...args) => {
+  return (path: string, ...args: any[]): string => {
     const message = get(messages[lang], prefix + path) || get(messages[lang], path);
     return typeof message === 'function' ? message(...args) : message;
   };

packages/utils/use/index.ts

@@ -2,7 +2,13 @@ import useBem from './bem';
 import useSfc from './sfc';
 import useI18n from './i18n';
 
-export function use(name) {
+type UseReturn = [
+  ReturnType<typeof useSfc>,
+  ReturnType<typeof useBem>,
+  ReturnType<typeof useI18n>
+];
+
+export function use(name: string): UseReturn {
   name = 'van-' + name;
   return [useSfc(name), useBem(name), useI18n(name)];
 }