fix(editor): Handle large payloads in the AI Assistant requests better (#12747)

packages/editor-ui/src/utils/objectUtils.ts

@@ -18,3 +18,35 @@ export const searchInObject = (obj: ObjectOrArray, searchString: string): boolea
 			? searchInObject(entry, searchString)
 			: entry?.toString().toLowerCase().includes(searchString.toLowerCase()),
 	);
+
+/**
+ * Calculate the size of a stringified object in KB.
+ * @param {unknown} obj - The object to calculate the size of
+ * @returns {number} The size of the object in KB
+ * @throws {Error} If the object is not serializable
+ */
+export const getObjectSizeInKB = (obj: unknown): number => {
+	if (obj === null || obj === undefined) {
+		return 0;
+	}
+
+	if (
+		(typeof obj === 'object' && Object.keys(obj).length === 0) ||
+		(Array.isArray(obj) && obj.length === 0)
+	) {
+		// "{}" and "[]" both take 2 bytes in UTF-8
+		return Number((2 / 1024).toFixed(2));
+	}
+
+	try {
+		const str = JSON.stringify(obj);
+		// Using TextEncoder to get actual UTF-8 byte length (what we see in chrome dev tools)
+		const bytes = new TextEncoder().encode(str).length;
+		const kb = bytes / 1024;
+		return Number(kb.toFixed(2));
+	} catch (error) {
+		throw new Error(
+			`Failed to calculate object size: ${error instanceof Error ? error.message : 'Unknown error'}`,
+		);
+	}
+};