All files / reactivity/src watch.ts

98.02% Statements 149/152
92.36% Branches 121/131
95.65% Functions 22/23
97.9% Lines 140/143

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374                                                            183x 183x 183x 183x                                                                                       183x       183x 183x                                                 44x 44x 44x 44x                           367x   367x 2x               367x   37x   20x 11x   9x             367x 367x   367x 223x 109x 258x 35x 15x 243x 11x 15x 11x 16x 24x 15x 9x 2x 7x 6x   1x     232x 231x   168x 233x       63x 105x 105x 105x 105x   105x     105x 105x 105x 105x       105x         1x 1x     367x 103x 103x 143x     367x 367x 53x 53x 29x       367x 8x 8x 8x 8x   8x         367x       367x 315x       10x   304x   232x 232x         3x     226x 226x 226x   226x 226x   225x 225x                   226x 226x         226x 226x         72x       367x 347x     367x   367x 198x     367x   367x 428x 428x 36x 25x   17x   26x       367x 360x 360x       367x 304x 28x   276x   63x 30x   33x     367x 367x 367x   367x               665x 358x     307x 665x 4x   303x 303x 303x 6x 297x 182x 314x   115x 30x 43x   85x 81x 96x   81x 13x 9x       303x    
import {
  EMPTY_OBJ,
  NOOP,
  hasChanged,
  isArray,
  isFunction,
  isMap,
  isObject,
  isPlainObject,
  isSet,
  remove,
} from '@vue/shared'
import { warn } from './warning'
import type { ComputedRef } from './computed'
import { ReactiveFlags } from './constants'
import {
  type DebuggerOptions,
  EffectFlags,
  type EffectScheduler,
  ReactiveEffect,
  pauseTracking,
  resetTracking,
} from './effect'
import { isReactive, isShallow } from './reactive'
import { type Ref, isRef } from './ref'
import { getCurrentScope } from './effectScope'
 
// These errors were transferred from `packages/runtime-core/src/errorHandling.ts`
// to @vue/reactivity to allow co-location with the moved base watch logic, hence
// it is essential to keep these values unchanged.
export enum WatchErrorCodes {
  WATCH_GETTER = 2,
  WATCH_CALLBACK,
  WATCH_CLEANUP,
}
 
export type WatchEffect = (onCleanup: OnCleanup) => void
 
export type WatchSource<T = any> = Ref<T, any> | ComputedRef<T> | (() => T)
 
export type WatchCallback<V = any, OV = any> = (
  value: V,
  oldValue: OV,
  onCleanup: OnCleanup,
) => any
 
export type OnCleanup = (cleanupFn: () => void) => void
 
export interface WatchOptions<Immediate = boolean> extends DebuggerOptions {
  immediate?: Immediate
  deep?: boolean | number
  once?: boolean
  scheduler?: WatchScheduler
  onWarn?: (msg: string, ...args: any[]) => void
  /**
   * @internal
   */
  augmentJob?: (job: (...args: any[]) => void) => void
  /**
   * @internal
   */
  call?: (
    fn: Function | Function[],
    type: WatchErrorCodes,
    args?: unknown[],
  ) => void
}
 
export type WatchStopHandle = () => void
 
export interface WatchHandle extends WatchStopHandle {
  pause: () => void
  resume: () => void
  stop: () => void
}
 
// initial value for watchers to trigger on undefined initial values
const INITIAL_WATCHER_VALUE = {}
 
export type WatchScheduler = (job: () => void, isFirstRun: boolean) => void
 
const cleanupMap: WeakMap<ReactiveEffect, (() => void)[]> = new WeakMap()
let activeWatcher: ReactiveEffect | undefined = undefined
 
/**
 * Returns the current active effect if there is one.
 */
export function getCurrentWatcher(): ReactiveEffect<any> | undefined {
  return activeWatcher
}
 
/**
 * Registers a cleanup callback on the current active effect. This
 * registered cleanup callback will be invoked right before the
 * associated effect re-runs.
 *
 * @param cleanupFn - The callback function to attach to the effect's cleanup.
 * @param failSilently - if `true`, will not throw warning when called without
 * an active effect.
 * @param owner - The effect that this cleanup function should be attached to.
 * By default, the current active effect.
 */
export function onWatcherCleanup(
  cleanupFn: () => void,
  failSilently = false,
  owner: ReactiveEffect | undefined = activeWatcher,
): void {
  if (owner) {
    let cleanups = cleanupMap.get(owner)
    if (!cleanups) cleanupMap.set(owner, (cleanups = []))
    cleanups.push(cleanupFn)
  } else Eif (__DEV__ && !failSilently) {
    warn(
      `onWatcherCleanup() was called when there was no active watcher` +
        ` to associate with.`,
    )
  }
}
 
export function watch(
  source: WatchSource | WatchSource[] | WatchEffect | object,
  cb?: WatchCallback | null,
  options: WatchOptions = EMPTY_OBJ,
): WatchHandle {
  const { immediate, deep, once, scheduler, augmentJob, call } = options
 
  const warnInvalidSource = (s: unknown) => {
    ;(options.onWarn || warn)(
      `Invalid watch source: `,
      s,
      `A watch source can only be a getter/effect function, a ref, ` +
        `a reactive object, or an array of these types.`,
    )
  }
 
  const reactiveGetter = (source: object) => {
    // traverse will happen in wrapped getter below
    if (deep) return source
    // for `deep: false | 0` or shallow reactive, only traverse root-level properties
    if (isShallow(source) || deep === false || deep === 0)
      return traverse(source, 1)
    // for `deep: undefined` on a reactive object, deeply traverse all properties
    return traverse(source)
  }
 
  let effect: ReactiveEffect
  let getter: () => any
  let cleanup: (() => void) | undefined
  let boundCleanup: typeof onWatcherCleanup
  let forceTrigger = false
  let isMultiSource = false
 
  if (isRef(source)) {
    getter = () => source.value
    forceTrigger = isShallow(source)
  } else if (isReactive(source)) {
    getter = () => reactiveGetter(source)
    forceTrigger = true
  } else if (isArray(source)) {
    isMultiSource = true
    forceTrigger = source.some(s => isReactive(s) || isShallow(s))
    getter = () =>
      source.map(s => {
        if (isRef(s)) {
          return s.value
        } else if (isReactive(s)) {
          return reactiveGetter(s)
        } else if (isFunction(s)) {
          return call ? call(s, WatchErrorCodes.WATCH_GETTER) : s()
        } else {
          __DEV__ && warnInvalidSource(s)
        }
      })
  } else if (isFunction(source)) {
    if (cb) {
      // getter with cb
      getter = call
        ? () => call(source, WatchErrorCodes.WATCH_GETTER)
        : (source as () => any)
    } else {
      // no cb -> simple effect
      getter = () => {
        Eif (cleanup) {
          pauseTracking()
          try {
            cleanup()
          } finally {
            resetTracking()
          }
        }
        const currentEffect = activeWatcher
        activeWatcher = effect
        try {
          return call
            ? call(source, WatchErrorCodes.WATCH_CALLBACK, [boundCleanup])
            : source(boundCleanup)
        } finally {
          activeWatcher = currentEffect
        }
      }
    }
  } else {
    getter = NOOP
    __DEV__ && warnInvalidSource(source)
  }
 
  if (cb && deep) {
    const baseGetter = getter
    const depth = deep === true ? Infinity : deep
    getter = () => traverse(baseGetter(), depth)
  }
 
  const scope = getCurrentScope()
  const watchHandle: WatchHandle = () => {
    effect.stop()
    if (scope && scope.active) {
      remove(scope.effects, effect)
    }
  }
 
  if (once && cb) {
    const _cb = cb
    cb = (...args) => {
      try {
        return _cb(...args)
      } finally {
        watchHandle()
      }
    }
  }
 
  let oldValue: any = isMultiSource
    ? new Array((source as []).length).fill(INITIAL_WATCHER_VALUE)
    : INITIAL_WATCHER_VALUE
 
  const job = (immediateFirstRun?: boolean) => {
    if (
      !(effect.flags & EffectFlags.ACTIVE) ||
      (!effect.dirty && !immediateFirstRun)
    ) {
      return
    }
    if (cb) {
      // watch(source, cb)
      const newValue = effect.run()
      if (
        immediateFirstRun ||
        deep ||
        forceTrigger ||
        (isMultiSource
          ? (newValue as any[]).some((v, i) => hasChanged(v, oldValue[i]))
          : hasChanged(newValue, oldValue))
      ) {
        const currentWatcher = activeWatcher
        pauseTracking()
        try {
          // cleanup before running cb again
          Eif (cleanup) {
            cleanup()
          }
          activeWatcher = effect
          const args = [
            newValue,
            // pass undefined as the old value when it's changed for the first time
            oldValue === INITIAL_WATCHER_VALUE
              ? undefined
              : isMultiSource && oldValue[0] === INITIAL_WATCHER_VALUE
                ? []
                : oldValue,
            boundCleanup,
          ]
          oldValue = newValue
          call
            ? call(cb!, WatchErrorCodes.WATCH_CALLBACK, args)
            : // @ts-expect-error
              cb!(...args)
        } finally {
          activeWatcher = currentWatcher
          resetTracking()
        }
      }
    } else {
      // watchEffect
      effect.run()
    }
  }
 
  if (augmentJob) {
    augmentJob(job)
  }
 
  effect = new ReactiveEffect(getter)
 
  effect.scheduler = scheduler
    ? () => scheduler(job, false)
    : (job as EffectScheduler)
 
  boundCleanup = fn => onWatcherCleanup(fn, false, effect)
 
  cleanup = effect.onStop = () => {
    const cleanups = cleanupMap.get(effect)
    if (cleanups) {
      if (call) {
        call(cleanups, WatchErrorCodes.WATCH_CLEANUP)
      } else {
        for (const cleanup of cleanups) cleanup()
      }
      cleanupMap.delete(effect)
    }
  }
 
  if (__DEV__) {
    effect.onTrack = options.onTrack
    effect.onTrigger = options.onTrigger
  }
 
  // initial run
  if (cb) {
    if (immediate) {
      job(true)
    } else {
      oldValue = effect.run()
    }
  } else if (scheduler) {
    scheduler(job.bind(null, true), true)
  } else {
    effect.run()
  }
 
  watchHandle.pause = effect.pause.bind(effect)
  watchHandle.resume = effect.resume.bind(effect)
  watchHandle.stop = watchHandle
 
  return watchHandle
}
 
export function traverse(
  value: unknown,
  depth: number = Infinity,
  seen?: Map<unknown, number>,
): unknown {
  if (depth <= 0 || !isObject(value) || (value as any)[ReactiveFlags.SKIP]) {
    return value
  }
 
  seen = seen || new Map()
  if ((seen.get(value) || 0) >= depth) {
    return value
  }
  seen.set(value, depth)
  depth--
  if (isRef(value)) {
    traverse(value.value, depth, seen)
  } else if (isArray(value)) {
    for (let i = 0; i < value.length; i++) {
      traverse(value[i], depth, seen)
    }
  } else if (isSet(value) || isMap(value)) {
    value.forEach((v: any) => {
      traverse(v, depth, seen)
    })
  } else if (isPlainObject(value)) {
    for (const key in value) {
      traverse(value[key], depth, seen)
    }
    for (const key of Object.getOwnPropertySymbols(value)) {
      if (Object.prototype.propertyIsEnumerable.call(value, key)) {
        traverse(value[key as any], depth, seen)
      }
    }
  }
  return value
}