Strange behavior with watch and watchEffect

[Danilouli]

vue-version: 3.2.25
browser environment: 102.0.5005.115
os : macOS Version 12.0.1

Here is a snippet :

const refA = ref(1);
const refB = ref(2);
const refC = ref(3);

watch(() => refA.value, (newRefAValue) => {
  console.log('WATCH on refA change displaying refC and refA');
  console.log('refA value:', newRefAValue, 'refC value:', refC.value);
});

watchEffect(() => {
  console.log('WATCH EFFECT changing refA value and triggered on refB change only normally');
  console.log('refB value:', refB.value);
  refA.value = Math.ceil(Math.random() * 10000);
});

onMounted(() => {
  window.addEventListener('change_ref_c', () => {
    refC.value = Math.ceil(Math.random() * 10000);
  });
});

Normally, when i trigger a window.dispatchEvent(new CustomEvent('change_ref_c')) in the browser console, only the watch callback should execute. But the watchEffect also execute once. After if I trigger again a 'change_ref_c' event, the watchEffect does not execut anymore. Of course, I have workarounds but I would like to know if it is a wanted behavior in the library. Do you have any ideas ?

Thanks everyone !

[liulinboyi]

I run it in the SFC, click the trigger button
to trigger the window.dispatchEvent(new CustomEvent('change_ref_c')) ,the code

watch(() => refA.value, (newRefAValue) => {
  console.log('WATCH on refA change displaying refC and refA');
  console.log('refA value:', newRefAValue, 'refC value:', refC.value);
});

watchEffect(() => {
  console.log('WATCH EFFECT changing refA value and triggered on refB change only normally');
  console.log('refB value:', refB.value);
  refA.value = Math.ceil(Math.random() * 10000);
});

are all not execut.
only my add new watchEffect

watchEffect(() => {
  debugger
  // will trigger
  console.log('refC',refC.value)
})

will execut.

[Danilouli]

Hello ! Thanks for this SFC. It seems that the vue version is the problem. If I set 3.2.25 in the SFC, it does th behavior I indicate. But I will modify my version for the latest 3.2.37 as it works well with newer versions.

Thanks for the answer @liulinboyi 👍 !