fix: loosen type checking for NextApiHandlers

src/index.ts

@@ -181,8 +181,12 @@ export interface NtarhInitPagesRouter<NextResponseJsonType = unknown>
    * The actual Pages Router route handler under test. It should be an async
    * function that accepts `NextApiRequest` and `NextApiResult` objects (in
    * that order) as its two parameters.
+   *
+   * Note that type checking for `res.send` and similar methods was retired in
+   * NTARH@4. Only the `response.json` method returned by NTARH's fetch wrapper
+   * will have a typed result.
    */
-  pagesHandler: NextApiHandler<NextResponseJsonType>;
+  pagesHandler: NextApiHandler<any>;
   appHandler?: undefined;
   /**
    * `params` is passed directly to the handler and represents processed dynamic

test/unit-index.test.ts

@@ -566,7 +566,10 @@ describe('::testApiHandler', () => {
 
       await testApiHandler<{ a: number }>({
         pagesHandler: async (_, res) => {
-          // @ts-expect-error: b does not exist (this test "fails" if no TS error)
+          // ? Formerly we would expect an error to be thrown here, but in
+          // ? NTARH@4 we've relaxed the type checking so that only fetch::json
+          // ? is affected. I believe this leads to more accurate and more
+          // ? useful type checking for NTARH users.
           res.send({ b: 1 });
         },
         test: async ({ fetch }) => {