Playwright Testing for GraphQL Federation and Supergraph Queries

This guide provides complete, production-ready Playwright patterns for playwright testing for graphql federation and supergraph queries.

Introduction

Robust test automation requires domain-specific patterns. This article covers playwright testing for graphql federation and supergraph queries with practical code examples you can use immediately in your test suite.

Architecture Overview

graph TD
    Test["Playwright Test"] --> App["Application Under Test"]
    App --> API["Backend API / Mock"]
    API --> Assert["Test Assertions Pass"]

Implementation

test('federated GraphQL returns data from multiple subgraphs', async ({ page }) => {
  await page.route('**/graphql', route => {
    route.fulfill({
      json: {
        data: {
          user: { id: '1', name: 'John' }, // From user subgraph
          orders: [{ id: 'O1', total: 99.99 }] // From orders subgraph
        }
      }
    });
  });
  await page.goto('/profile');
  await expect(page.getByText('John')).toBeVisible();
  await expect(page.getByText('$99.99')).toBeVisible();
});

Run Tests

npx playwright test --grep "Playwright Testing for"
npx playwright test --ui

Reference Table

Best Practices

Common Mistakes

Frequently Asked Questions

How to test Apollo Federation gateway with Playwright?

Mock the gateway's GraphQL endpoint and return combined subgraph data to test frontend rendering.

How to test federated query error handling?

Return partial errors from one subgraph and verify your app handles the partial data gracefully.

Can Playwright test GraphQL subscription federation?

Mock the WebSocket subscription transport and verify federated real-time data flows to the UI.

How to test supergraph schema changes?

When schema evolves, update mocks to match new types and run tests to catch breaking changes.

How to test GraphQL persisted queries?

Verify the client sends persisted query hashes and the gateway resolves them correctly.

Summary

This guide covered playwright testing for graphql federation and supergraph queries. Apply these patterns to build reliable, fast, and maintainable automation for this specific scenario.

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