New source found from dndbeyond.com

ddb_main/tools/js/smartComponents/hooks/useEffectExceptOnMount.ts

@@ -0,0 +1,32 @@
+import React, {
+  DependencyList,
+  EffectCallback,
+  useEffect,
+  useRef,
+} from "react";
+
+/**
+ * React.useEffect, except that it never runs on mount.
+ * This is emulating the componentDidUpdate lifecycle function.
+ */
+export const useEffectExceptOnMount = (
+  effect: EffectCallback,
+  dependencies?: DependencyList
+): void => {
+  const mounted = useRef(false);
+  useEffect(() => {
+    if (mounted.current) {
+      const unmount = effect();
+      return () => unmount && unmount();
+    } else {
+      mounted.current = true;
+    }
+  }, dependencies);
+
+  //Reset on unmount for the next mount.
+  useEffect(() => {
+    return () => {
+      mounted.current = false;
+    };
+  }, []);
+};