QABattle

API Testing / Scenario

The Contract Break Investigation

Mobile checkout is crashing after a backend deploy. Read the diff, the error, and the contract, then place the blame precisely.

Difficulty
Hard
Format
Scenario
Points
200
Estimate
14 min

// MISSION BRIEF

Your Mission

The mobile team is furious: checkout crashes on the latest backend deploy. The backend team insists "we didn't break the API."

You have the API response diff, the mobile crash log, and the OpenAPI contract. Somebody's wrong. Figure out who, exactly how, and what process would have caught it.

// FIRST CONTACT

Battle teaser

First artifact

GET /api/v1/cart, response before vs after deploy

Which changes in the new response are BREAKING per the published contract? (Select all that apply.)

  1. Aprice: number → string
  2. Bestimated_delivery renamed to estimatedDelivery
  3. Ctotal: number → string
  4. Ddiscount: null → object with amount 0
Answers, scoring, hints, and the full battle stay sealed.

// SKILL TAGS

contractsopenapibreaking-changespact