init

mc_test/node_modules/zustand/esm/react/shallow.js

@@ -0,0 +1,49 @@
+import ReactExports from 'react';
+
+function shallow(objA, objB) {
+  if (Object.is(objA, objB)) {
+    return true;
+  }
+  if (typeof objA !== "object" || objA === null || typeof objB !== "object" || objB === null) {
+    return false;
+  }
+  if (objA instanceof Map && objB instanceof Map) {
+    if (objA.size !== objB.size) return false;
+    for (const [key, value] of objA) {
+      if (!Object.is(value, objB.get(key))) {
+        return false;
+      }
+    }
+    return true;
+  }
+  if (objA instanceof Set && objB instanceof Set) {
+    if (objA.size !== objB.size) return false;
+    for (const value of objA) {
+      if (!objB.has(value)) {
+        return false;
+      }
+    }
+    return true;
+  }
+  const keysA = Object.keys(objA);
+  if (keysA.length !== Object.keys(objB).length) {
+    return false;
+  }
+  for (const keyA of keysA) {
+    if (!Object.prototype.hasOwnProperty.call(objB, keyA) || !Object.is(objA[keyA], objB[keyA])) {
+      return false;
+    }
+  }
+  return true;
+}
+
+const { useRef } = ReactExports;
+function useShallow(selector) {
+  const prev = useRef();
+  return (state) => {
+    const next = selector(state);
+    return shallow(prev.current, next) ? prev.current : prev.current = next;
+  };
+}
+
+export { useShallow };