fix flow

src/platforms/web/runtime/modules/transition.js

@@ -4,6 +4,7 @@ import { once, isObject, toNumber } from 'shared/util'
 import { inBrowser, isIE9, warn } from 'core/util/index'
 import { mergeVNodeHook } from 'core/vdom/helpers/index'
 import { activeInstance } from 'core/instance/lifecycle'
+
 import {
   nextFrame,
   resolveTransition,
@@ -68,16 +69,35 @@ export function enter (vnode: VNodeWithData, toggleDisplay: ?() => void) {
     return
   }
 
-  const startClass = isAppear && appearClass ? appearClass : enterClass
-  const activeClass = isAppear && appearActiveClass ? appearActiveClass : enterActiveClass
-  const toClass = isAppear && appearToClass ? appearToClass : enterToClass
-
-  const beforeEnterHook = isAppear ? (beforeAppear || beforeEnter) : beforeEnter
-  const enterHook = isAppear ? (typeof appear === 'function' ? appear : enter) : enter
-  const afterEnterHook = isAppear ? (afterAppear || afterEnter) : afterEnter
-  const enterCancelledHook = isAppear ? (appearCancelled || enterCancelled) : enterCancelled
+  const startClass = isAppear && appearClass
+    ? appearClass
+    : enterClass
+  const activeClass = isAppear && appearActiveClass
+    ? appearActiveClass
+    : enterActiveClass
+  const toClass = isAppear && appearToClass
+    ? appearToClass
+    : enterToClass
+
+  const beforeEnterHook = isAppear
+    ? (beforeAppear || beforeEnter)
+    : beforeEnter
+  const enterHook = isAppear
+    ? (typeof appear === 'function' ? appear : enter)
+    : enter
+  const afterEnterHook = isAppear
+    ? (afterAppear || afterEnter)
+    : afterEnter
+  const enterCancelledHook = isAppear
+    ? (appearCancelled || enterCancelled)
+    : enterCancelled
+
+  const explicitEnterDuration: any = toNumber(
+    isObject(duration)
+      ? duration.enter
+      : duration
+  )
 
-  const explicitEnterDuration = toNumber(isObject(duration) ? duration.enter : duration)
   if (process.env.NODE_ENV !== 'production' && explicitEnterDuration != null) {
     checkDuration(explicitEnterDuration, 'enter', vnode)
   }
@@ -179,7 +199,12 @@ export function leave (vnode: VNodeWithData, rm: Function) {
   const expectsCSS = css !== false && !isIE9
   const userWantsControl = getHookAgumentsLength(leave)
 
-  const explicitLeaveDuration = toNumber(isObject(duration) ? duration.leave : duration)
+  const explicitLeaveDuration: any = toNumber(
+    isObject(duration)
+      ? duration.leave
+      : duration
+  )
+
   if (process.env.NODE_ENV !== 'production' && explicitLeaveDuration != null) {
     checkDuration(explicitLeaveDuration, 'leave', vnode)
   }