Network failures

Use route.abort() to exercise application error handling without flaky real network conditions.

Simulate a timeout

test("shows retry copy when payments time out", async ({ page, backendMocks }) => {
  await backendMocks.route("https://payments.example.test/**", async (route) => {
    await route.abort("timedout");
  });

  await page.goto("/checkout");
  await page.getByRole("button", { name: "Pay" }).click();

  await expect(page.getByText(/timed out|try again/i)).toBeVisible();
});

Simulate DNS failure

await backendMocks.route("https://api.example.test/**", async (route) => {
  await route.abort("namenotresolved");
});

Available protocol codes

Code	Default message
failed	net::ERR_FAILED
aborted	net::ERR_ABORTED
timedout	net::ERR_TIMED_OUT
connectionrefused	net::ERR_CONNECTION_REFUSED
connectionreset	net::ERR_CONNECTION_RESET
namenotresolved	net::ERR_NAME_NOT_RESOLVED

Omitting the code is equivalent to abort("failed").

Fail only one request

Use times when only the next call should fail.

await backendMocks.route(
  "https://api.example.test/reports",
  async (route) => {
    await route.abort("connectionreset");
  },
  { times: 1 },
);

Later calls match older handlers or pass through.

Assert the app behavior

Different HTTP clients expose network failures differently. Prefer user-visible assertions:

await expect(page.getByRole("alert")).toContainText("Please try again");

See Abort and failures and Errors.