refactor: simplify implementations

since we output es5, classes are more verbose then necessary

src/composition-api/reactivity/computed.ts

@@ -13,7 +13,7 @@ export interface ComputedRef<T = any> extends WritableComputedRef<T> {
 }
 
 export interface WritableComputedRef<T> extends Ref<T> {
-  readonly effect: { stop(): void }
+  readonly effect: Watcher
 }
 
 export type ComputedGetter<T> = (...args: any[]) => T
@@ -53,54 +53,31 @@ export function computed<T>(
     setter = getterOrOptions.set
   }
 
-  return new ComputedRefImpl(
-    getter,
-    setter,
-    onlyGetter,
-    isServerRendering()
-  ) as any
-}
-
-class ComputedRefImpl<T> {
-  public dep?: Dep = undefined
-
-  public readonly __v_isRef = true
-  public readonly effect
-
-  private _watcher: Watcher | null
-
-  constructor(
-    private _getter: ComputedGetter<T>,
-    private readonly _setter: ComputedSetter<T>,
-    public readonly __v_isReadonly: boolean,
-    isSSR: boolean
-  ) {
-    const watcher = (this._watcher = isSSR
-      ? null
-      : new Watcher(currentInstance, _getter, noop, { lazy: true }))
-    this.effect = {
-      stop() {
-        watcher && watcher.teardown()
-      }
-    }
-  }
+  const watcher = isServerRendering()
+    ? null
+    : new Watcher(currentInstance, getter, noop, { lazy: true })
 
-  get value() {
-    const watcher = this._watcher
-    if (watcher) {
-      if (watcher.dirty) {
-        watcher.evaluate()
-      }
-      if (Dep.target) {
-        watcher.depend()
+  return {
+    __v_isRef: true,
+    __v_isReadonly: onlyGetter,
+    // some libs rely on the presence effect for checking computed refs
+    // from normal refs, but the implementation doesn't matter
+    effect: watcher,
+    get value() {
+      if (watcher) {
+        if (watcher.dirty) {
+          watcher.evaluate()
+        }
+        if (Dep.target) {
+          watcher.depend()
+        }
+        return watcher.value
+      } else {
+        return getter()
       }
-      return watcher.value
-    } else {
-      return this._getter()
+    },
+    set value(newVal) {
+      setter(newVal)
     }
-  }
-
-  set value(newValue: T) {
-    this._setter(newValue)
-  }
+  } as any
 }

src/composition-api/reactivity/ref.ts

@@ -76,33 +76,21 @@ export type CustomRefFactory<T> = (
   set: (value: T) => void
 }
 
-class CustomRefImpl<T> {
-  public dep = new Dep()
-  private readonly _get: ReturnType<CustomRefFactory<T>>['get']
-  private readonly _set: ReturnType<CustomRefFactory<T>>['set']
-
-  public readonly __v_isRef = true
-
-  constructor(factory: CustomRefFactory<T>) {
-    const { get, set } = factory(
-      () => this.dep.depend(),
-      () => this.dep.notify()
-    )
-    this._get = get
-    this._set = set
-  }
-
-  get value() {
-    return this._get()
-  }
-
-  set value(newVal) {
-    this._set(newVal)
-  }
-}
-
 export function customRef<T>(factory: CustomRefFactory<T>): Ref<T> {
-  return new CustomRefImpl(factory) as any
+  const dep = new Dep()
+  const { get, set } = factory(
+    () => dep.depend(),
+    () => dep.notify()
+  )
+  return {
+    __v_isRef: true,
+    get value() {
+      return get()
+    },
+    set value(newVal) {
+      set(newVal)
+    }
+  } as any
 }
 
 export type ToRefs<T = any> = {
@@ -120,25 +108,6 @@ export function toRefs<T extends object>(object: T): ToRefs<T> {
   return ret
 }
 
-class ObjectRefImpl<T extends object, K extends keyof T> {
-  public readonly __v_isRef = true
-
-  constructor(
-    private readonly _object: T,
-    private readonly _key: K,
-    private readonly _defaultValue?: T[K]
-  ) {}
-
-  get value() {
-    const val = this._object[this._key]
-    return val === undefined ? (this._defaultValue as T[K]) : val
-  }
-
-  set value(newVal) {
-    this._object[this._key] = newVal
-  }
-}
-
 export type ToRef<T> = IfAny<T, Ref<T>, [T] extends [Ref] ? T : Ref<T>>
 
 export function toRef<T extends object, K extends keyof T>(
@@ -158,9 +127,19 @@ export function toRef<T extends object, K extends keyof T>(
   defaultValue?: T[K]
 ): ToRef<T[K]> {
   const val = object[key]
-  return isRef(val)
-    ? val
-    : (new ObjectRefImpl(object, key, defaultValue) as any)
+  if (isRef(val)) {
+    return val as any
+  }
+  return {
+    __v_isRef: true,
+    get value() {
+      const val = object[key]
+      return val === undefined ? (defaultValue as T[K]) : val
+    },
+    set value(newVal) {
+      object[key] = newVal
+    }
+  } as any
 }
 
 /**

test/unit/features/composition-api/reactivity/computed.spec.ts

@@ -131,7 +131,7 @@ describe('reactivity/computed', () => {
     expect(dummy).toBe(undefined)
     value.foo = 1
     expect(dummy).toBe(1)
-    cValue.effect.stop()
+    cValue.effect.teardown()
     value.foo = 2
     expect(dummy).toBe(1)
   })
@@ -221,7 +221,7 @@ describe('reactivity/computed', () => {
 
   it('should expose value when stopped', () => {
     const x = computed(() => 1)
-    x.effect.stop()
+    x.effect.teardown()
     expect(x.value).toBe(1)
   })