test-strategy-design

name	test-strategy-design
description	Design a test strategy on the pyramid: map defect classes to the cheapest test level that catches them, prioritize by risk, use coverage as a floor and mutation testing as the quality truth, and decide what not to test.

Test Strategy Design

Purpose: a suite that catches real defects cheaply.

The pyramid

  /\   few   E2E (critical journeys)
 /--\  some  integration (component interactions)
/----\ many  unit (logic) — fast & deterministic

Invert the ice-cream cone (mostly E2E) — it's slow and flaky.

Match level to defect

• Logic bug -> unit
• Component/contract interaction -> integration
• Critical user journey -> E2E (few)

Coverage vs quality

Line/branch coverage = floor (finds untested code). Mutation testing = truth (does the suite fail when code is wrong?). Decide what NOT to test (trivial getters, framework, third-party).