perf[utils.js]: perf parseTime function

src/utils/index.js

@@ -6,7 +6,7 @@
  * Parse the time to string
  * @param {(Object|string|number)} time
  * @param {string} cFormat
- * @returns {string}
+ * @returns {string | null}
  */
 export function parseTime(time, cFormat) {
   if (arguments.length === 0) {
@@ -34,14 +34,11 @@ export function parseTime(time, cFormat) {
     s: date.getSeconds(),
     a: date.getDay()
   }
-  const time_str = format.replace(/{(y|m|d|h|i|s|a)+}/g, (result, key) => {
-    let value = formatObj[key]
+  const time_str = format.replace(/{([ymdhisa])+}/g, (result, key) => {
+    const value = formatObj[key]
     // Note: getDay() returns 0 on Sunday
     if (key === 'a') { return ['日', '一', '二', '三', '四', '五', '六'][value ] }
-    if (result.length > 0 && value < 10) {
-      value = '0' + value
-    }
-    return value || 0
+    return value.toString().padStart(2, '0')
   })
   return time_str
 }