test: baseWatch with onEffectCleanup

packages/reactivity/__tests__/baseWatch.spec.ts

@@ -0,0 +1,109 @@
+import {
+  type Scheduler,
+  type SchedulerJob,
+  baseWatch,
+  onEffectCleanup,
+} from '../src/baseWatch'
+import { EffectScope } from '../src/effectScope'
+import { type Ref, ref } from '../src/ref'
+
+const queue: SchedulerJob[] = []
+
+let isFlushPending = false
+const resolvedPromise = /*#__PURE__*/ Promise.resolve() as Promise<any>
+const nextTick = (fn?: () => any) =>
+  fn ? resolvedPromise.then(fn) : resolvedPromise
+const scheduler: Scheduler = ({ job }) => {
+  queue.push(job)
+  flushJobs()
+}
+const flushJobs = () => {
+  if (isFlushPending) return
+  isFlushPending = true
+  resolvedPromise.then(() => {
+    queue.forEach(job => job())
+    queue.length = 0
+    isFlushPending = false
+  })
+}
+
+describe('baseWatch with onEffectCleanup', () => {
+  test('basic', async () => {
+    let dummy = 0
+    let source: Ref<number>
+    const scope = new EffectScope()
+
+    scope.run(() => {
+      source = ref(0)
+      baseWatch(onCleanup => {
+        source.value
+
+        onCleanup(() => (dummy += 2))
+        onEffectCleanup(() => (dummy += 3))
+        onEffectCleanup(() => (dummy += 5))
+      })
+    })
+    expect(dummy).toBe(0)
+
+    scope.run(() => {
+      source.value++
+    })
+    expect(dummy).toBe(10)
+
+    scope.run(() => {
+      source.value++
+    })
+    expect(dummy).toBe(20)
+
+    scope.stop()
+    expect(dummy).toBe(30)
+  })
+
+  test('nested call to baseWatch', async () => {
+    let calls: string[] = []
+    let source: Ref<number>
+    let copyist: Ref<number>
+    const scope = new EffectScope()
+
+    scope.run(() => {
+      source = ref(0)
+      copyist = ref(0)
+      // sync by default
+      baseWatch(
+        () => {
+          const current = (copyist.value = source.value)
+          onEffectCleanup(() => calls.push(`sync ${current}`))
+        },
+        null,
+        {},
+      )
+      // with scheduler
+      baseWatch(
+        () => {
+          const current = copyist.value
+          onEffectCleanup(() => calls.push(`post ${current}`))
+        },
+        null,
+        { scheduler },
+      )
+    })
+
+    await nextTick()
+    expect(calls).toEqual([])
+
+    scope.run(() => source.value++)
+    expect(calls).toEqual(['sync 0'])
+    await nextTick()
+    expect(calls).toEqual(['sync 0', 'post 0'])
+    calls.length = 0
+
+    scope.run(() => source.value++)
+    expect(calls).toEqual(['sync 1'])
+    await nextTick()
+    expect(calls).toEqual(['sync 1', 'post 1'])
+    calls.length = 0
+
+    scope.stop()
+    expect(calls).toEqual(['sync 2', 'post 2'])
+  })
+})

packages/reactivity/src/baseWatch.ts

@@ -116,7 +116,7 @@ export function onEffectCleanup(cleanupFn: () => void) {
 
 export function baseWatch(
   source: WatchSource | WatchSource[] | WatchEffect | object,
-  cb: WatchCallback | null,
+  cb?: WatchCallback | null,
   {
     immediate,
     deep,