fix(useLabels): deep merge labels

packages/core/src/hooks/useLabels.ts

@@ -1,7 +1,10 @@
 import { useMemo } from "react";
 
-export function useLabels<T>(defaultLabels: T, labels?: Partial<T>): T {
+import { DeepPartial } from "../types/generic";
+import { deepMerge } from "../utils/deepMerge";
+
+export function useLabels<T>(defaultLabels: T, labels?: DeepPartial<T>): T {
   return useMemo(() => {
-    return { ...defaultLabels, ...labels };
+    return deepMerge(defaultLabels, labels);
   }, [defaultLabels, labels]);
 }

packages/core/src/utils/deepMerge.ts

@@ -0,0 +1,21 @@
+import { DeepPartial } from "../types/generic";
+
+const isObject = (val: any): val is Object =>
+  val && typeof val === "object" && !Array.isArray(val);
+
+function merge<T>(target: T, source?: DeepPartial<T>) {
+  Object.keys(source || {}).forEach((key) => {
+    if (isObject(target[key]) && isObject(source?.[key])) {
+      merge(target[key], source?.[key]);
+    } else {
+      target[key] = source?.[key];
+    }
+  });
+}
+
+/** Merges recursively all keys of source into target returning the resulting object. */
+export function deepMerge<T>(target: T, source?: DeepPartial<T>): T {
+  const result = structuredClone(target);
+  merge(result, source);
+  return result;
+}