Courses / Frontend Testing
16. end-to-end vs unit test boundaries
Deciding which behaviors should be covered by fast unit/component tests versus E2E tests.
JavaScript
end-to-end vs unit test boundaries
Deciding which behaviors to test quickly in unit/component tests and which to cover with slower end-to-end (E2E) tests.
"I want fast feedback for most bugs, but one flaky E2E catch saved production once—how do I split tests?"
Unit/component tests verify small, isolated code units quickly; E2E tests verify the whole system flow including integrations and infrastructure. Choose unit tests for logic and boundaries, and E2E for integration, orchestration, and user-visible flows.
"I want fast feedback for most bugs, but one flaky E2E catch saved production once—how do I split tests?"
Unit/component tests verify small, isolated code units quickly; E2E tests verify the whole system flow including integrations and infrastructure. Choose unit tests for logic and boundaries, and E2E for integration, orchestration, and user-visible flows.