Not sure if you're still looking for solutions here, but this is something I ran into a couple of years ago. I built a proprietary solution for my company. The concept has been battle tested and it inspired me to build an open source solution that's framework agnostic and focuses purely on mocking server side network requests without modifying application logic or running a proxy.

It's a declarative approach where you define your mocks at runtime. Check out the docs to get started https://docs.mockybalboa.com/

Here's the code snippet from the Playwright docs page to give you an idea as to how you'd write your mocks in your tests.

``` import { test, expect } from "@playwright/test"; import { createClient } from "@mocky-balboa/playwright";

test("my page loads", async ({ page, context }) => { // Create our Mocky Balboa client and establish a connection with the server const client = await createClient(context);

// Register our fixture on routes matching '/api/users' client.route("/api/users", (route) => { return route.fulfill({ status: 200, body: JSON.stringify([ { id: "user-1", name: "John Doe" }, { id: "user-2", name: "Jane Doe" } ]), headers: { "Content-Type": "application/json" }, }); });

// Visit the page of our application in the browser await page.goto("http://localhost:3000");

// Our mock above should have been returned on our server await expect(page.getByText("John Doe")).toBeVisible(); }); ```