Write tests that are stable, independent, and non-flaky by following proper isolation and waiting practices. Tests should create their own data, clean up after themselves, and avoid dependencies on other tests or external state. Key practices: - **Test Isolation**: Each test should create its own test data and clean up afterward to avoid dependencies between tests - **Proper Waiting**: Use `waitForLoadState("networkidle")` or wait for specific elements instead of arbitrary timeouts with `waitForTimeout()` - **Avoid Hardcoded Values**: Use dynamic values (like `randomString()`) instead of hardcoded identifiers that might conflict - **Cleanup Resources**: Always clean up created test data to prevent state leakage Example of proper test isolation: ```typescript it("should create the membership of the org", async () => { // Create test user for this specific test const testUserForCreate = await userRepositoryFixture.create({ email: `test-create-${randomString()}@api.com`, username: `test-create-${randomString()}`, }); return request(app.getHttpServer()) .post(`/v2/organizations/${org.id}/memberships`) .send({ userId: testUserForCreate.id, accepted: true, role: "MEMBER" }) .expect(201) .then(async (response) => { const createdMembership = response.body.data; // ... assertions ... // Clean up await membershipRepositoryFixture.delete(createdMembership.id); await userRepositoryFixture.deleteByEmail(testUserForCreate.email); }); }); ``` Reliable tests reduce CI failures, improve developer confidence, and prevent blocking of development workflows.