Add jsdoc

response.js

@@ -1,11 +1,25 @@
 /**
+ * Creates a new Response object by copying the body and headers from an existing Response object.
  * Difference between cloning and copying of a `Response`:
  * https://community.cloudflare.com/t/whats-the-point-of-response-clone/216456
+ *
+ * @param {Response} response - The Response object to copy.
+ * @returns {Response} A new Response object with the same body and headers as the input Response object.
  */
 export function copyResponse(response) {
   return new Response(response.body, response);
 }
 
+/**
+ * Determines the appropriate body value for a Response object based on the input value.
+ * If the input is already a string, it is returned as-is.
+ * If the input is undefined or null, an empty string is returned.
+ * If the input is a supported type for the Response body, it is returned as-is.
+ * Otherwise, the input is converted to a JSON string.
+ *
+ * @param {*} input - The input value to determine the Response body for.
+ * @returns {BodyInit} The appropriate body value for the Response object.
+ */
 export function getResponseBody(input) {
   if (typeof input === "string") {
     return input;