CORS Preflight Block

Simulate a browser-style CORS/network failure and assert that the UI explains the blocked integration.

Playwright

await injectChaos(page, {
  seed: 42,
  network: { cors: [{ urlPattern: '/api/external-tax', methods: ['OPTIONS', 'POST'], probability: 1 }] },
});
await page.goto('/checkout');
await page.click('#estimate-tax');
await expect(page.locator('[data-testid="tax-service-error"]')).toBeVisible();
expect((await getChaosLog(page)).some((event) => event.type === 'network:cors' && event.applied)).toBe(true);

Cypress

cy.injectChaos({
  seed: 42,
  network: { cors: [{ urlPattern: '/api/external-tax', methods: ['OPTIONS', 'POST'], probability: 1 }] },
});
cy.visit('/checkout');
cy.get('#estimate-tax').click();
cy.get('[data-testid="tax-service-error"]').should('be.visible');
cy.getChaosLog().should((log) => {
  expect(log.some((event) => event.type === 'network:cors' && event.applied)).to.equal(true);
});

WebdriverIO

await browser.url('/checkout');
await injectChaos(browser, {
  seed: 42,
  network: { cors: [{ urlPattern: '/api/external-tax', methods: ['OPTIONS', 'POST'], probability: 1 }] },
});
await $('#estimate-tax').click();
await expect($('[data-testid="tax-service-error"]')).toBeDisplayed();
expect((await getChaosLog(browser)).some((event) => event.type === 'network:cors' && event.applied)).toBe(true);

Puppeteer

await injectChaos(page, {
  seed: 42,
  network: { cors: [{ urlPattern: '/api/external-tax', methods: ['OPTIONS', 'POST'], probability: 1 }] },
});
await page.goto('http://localhost:3000/checkout');
await page.click('#estimate-tax');
await page.waitForSelector('[data-testid="tax-service-error"]');
const log = await getChaosLog(page);
if (!log.some((event) => event.type === 'network:cors' && event.applied)) {
  throw new Error('Expected CORS chaos');
}