fix: make Serializable type any (#9059)

docs/src/api/class-request.md

@@ -102,7 +102,7 @@ Request's post body in a binary form, if any.
 
 ## method: Request.postDataJSON
 * langs: js, python
-- returns: <[null]|[any]>
+- returns: <[null]|[Serializable]>
 
 Returns parsed request's body for `form-urlencoded` and JSON as a fallback if any.
 

types/structs.d.ts

@@ -19,7 +19,7 @@ import { JSHandle, ElementHandle, Frame, Page, BrowserContext, Locator } from '.
 /**
  * Can be converted to JSON
  */
-export type Serializable = {};
+export type Serializable = any;
 /**
  * Can be converted to JSON, but may also contain JSHandles.
  */

types/types.d.ts

@@ -13420,7 +13420,7 @@ export interface Request {
    * When the response is `application/x-www-form-urlencoded` then a key/value object of the values will be returned.
    * Otherwise it will be parsed as JSON.
    */
-  postDataJSON(): null|any;
+  postDataJSON(): null|Serializable;
 
   /**
    * Request that was redirected by the server to this one, if any.

utils/generate_types/test/test.ts

@@ -793,10 +793,11 @@ playwright.chromium.launch().then(async browser => {
 (async () => {
   const browser = await playwright.chromium.launch();
   const page = await browser.newPage();
-  await Promise.all([
+  const [response] = await Promise.all([
     page.waitForResponse(response => response.url().includes('example.com')),
     page.goto('https://example.com')
   ]);
+  console.log((await response!.json()).foobar); // JSON return value should be any
 
   await browser.close();
 })();