Switch lodash.isEqualWith to fast-equals (#4446)

CHANGELOG.md

@@ -15,6 +15,11 @@ it according to semantic versioning. For example, if your PR adds a breaking cha
 should change the heading of the (upcoming) version to include a major version bump.
 
 -->
+# 5.24.2
+
+## @rjsf/utils
+
+- switch `lodash.isEqualWith` to `fast-equals.createCustomEqual` providing `areFunctionsEqual` assuming any functions are equal.
 
 # 5.24.1
 

packages/utils/package.json

@@ -36,6 +36,7 @@
     "react": "^16.14.0 || >=17"
   },
   "dependencies": {
+    "fast-equals": "^5.2.2",
     "json-schema-merge-allof": "^0.8.1",
     "jsonpointer": "^5.0.1",
     "lodash": "^4.17.21",

packages/utils/src/deepEquals.ts

@@ -1,19 +1,22 @@
-import isEqualWith from 'lodash/isEqualWith';
+import { createCustomEqual } from 'fast-equals';
 
-/** Implements a deep equals using the `lodash.isEqualWith` function, that provides a customized comparator that
- * assumes all functions are equivalent.
+/** Implements a deep equals using the `fast-equals.createCustomEqual` function, providing a customized comparator that assumes all functions are equivalent.
  *
  * @param a - The first element to compare
  * @param b - The second element to compare
  * @returns - True if the `a` and `b` are deeply equal, false otherwise
  */
-export default function deepEquals(a: any, b: any): boolean {
-  return isEqualWith(a, b, (obj: any, other: any) => {
-    if (typeof obj === 'function' && typeof other === 'function') {
-      // Assume all functions are equivalent
-      // see https://github.com/rjsf-team/react-jsonschema-form/issues/255
-      return true;
-    }
-    return undefined; // fallback to default isEquals behavior
-  });
-}
+const deepEquals = createCustomEqual({
+  createCustomConfig: () => ({
+    // Assume all functions are equivalent
+    // see https://github.com/rjsf-team/react-jsonschema-form/issues/255
+    //
+    // Performance improvement: knowing that typeof a === function, so, only needs to check if typeof b === function.
+    // https://github.com/planttheidea/fast-equals/blob/c633c4e653cacf8fd5cbb309b6841df62322d74c/src/comparator.ts#L99
+    areFunctionsEqual(_a, b) {
+      return typeof b === 'function';
+    },
+  }),
+});
+
+export default deepEquals;