refactor: use utils isFunction (#768)

Co-authored-by: webfansplz <>

src/apis/computed.ts

@@ -5,6 +5,7 @@ import {
   noopFn,
   defineComponentInstance,
   getVueInternalClasses,
+  isFunction,
 } from '../utils'
 
 export interface ComputedRef<T = any> extends WritableComputedRef<T> {
@@ -35,7 +36,7 @@ export function computed<T>(
   let getter: ComputedGetter<T>
   let setter: ComputedSetter<T> | undefined
 
-  if (typeof getterOrOptions === 'function') {
+  if (isFunction(getterOrOptions)) {
     getter = getterOrOptions
   } else {
     getter = getterOrOptions.get

src/apis/watch.ts

@@ -432,7 +432,7 @@ export function watch<T = any>(
   options?: WatchOptions
 ): WatchStopHandle {
   let callback: WatchCallback<unknown> | null = null
-  if (typeof cb === 'function') {
+  if (isFunction(cb)) {
     // source watch
     callback = cb as WatchCallback<unknown>
   } else {

src/install.ts

@@ -1,6 +1,6 @@
 import type { VueConstructor } from 'vue'
 import { AnyObject } from './types/basic'
-import { hasSymbol, hasOwn, isPlainObject, warn } from './utils'
+import { isFunction, hasSymbol, hasOwn, isPlainObject, warn } from './utils'
 import { isRef } from './reactivity'
 import { setVueConstructor, isVueRegistered } from './runtimeContext'
 import { mixin } from './mixin'
@@ -67,8 +67,8 @@ export function install(Vue: VueConstructor) {
   ) {
     return function mergedSetupFn(props: any, context: any) {
       return mergeData(
-        typeof parent === 'function' ? parent(props, context) || {} : undefined,
-        typeof child === 'function' ? child(props, context) || {} : undefined
+        isFunction(parent) ? parent(props, context) || {} : undefined,
+        isFunction(child) ? child(props, context) || {} : undefined
       )
     }
   }

src/mixin.ts

@@ -60,7 +60,7 @@ export function mixin(Vue: VueConstructor) {
     if (!setup) {
       return
     }
-    if (typeof setup !== 'function') {
+    if (!isFunction(setup)) {
       if (__DEV__) {
         warn(
           'The "setup" option should be a function that returns a object in component definitions.',
@@ -74,7 +74,7 @@ export function mixin(Vue: VueConstructor) {
     // wrapper the data option, so we can invoke setup before data get resolved
     $options.data = function wrappedData() {
       initSetup(vm, vm.$props)
-      return typeof data === 'function'
+      return isFunction(data)
         ? (
             data as (this: ComponentInstance, x: ComponentInstance) => object
           ).call(vm, vm)

src/runtimeContext.ts

@@ -1,6 +1,13 @@
 import type { VueConstructor, VNode } from 'vue'
 import { ComponentInstance, Data } from './component'
-import { assert, hasOwn, warn, proxy, UnionToIntersection } from './utils'
+import {
+  assert,
+  hasOwn,
+  warn,
+  proxy,
+  UnionToIntersection,
+  isFunction,
+} from './utils'
 
 let vueDependency: VueConstructor | undefined = undefined
 
@@ -25,7 +32,7 @@ let currentInstance: ComponentInstance | null = null
 const PluginInstalledFlag = '__composition_api_installed__'
 
 function isVue(obj: any): obj is VueConstructor {
-  return obj && typeof obj === 'function' && obj.name === 'Vue'
+  return obj && isFunction(obj) && obj.name === 'Vue'
 }
 
 export function isPluginInstalled() {