vue-hooks-plus/lib/usePrevious/index.js

Vue hooks library

"use strict";
const vue = require("vue");
const defaultShouldUpdate = (a, b) => !Object.is(a, b);
function usePrevious(state, shouldUpdate = defaultShouldUpdate) {
  const prevRef = vue.ref();
  const curRef = vue.ref();
  vue.watchEffect(() => {
    if (shouldUpdate(curRef.value, state.value)) {
      prevRef.value = curRef.value;
      curRef.value = state.value;
    }
  });
  return vue.readonly(prevRef);
}
module.exports = usePrevious;