QABattle

BDD & TDD / Scenario

The Coverage Mirage

A repo claims TDD and 96% coverage. The commit log, one assertion-free test, and a wall of mock-verifies say otherwise. Audit it.

Difficulty
Hard
Format
Scenario
Points
200
Estimate
14 min

// MISSION BRIEF

Your Mission

Your team inherited a service whose README says "built with TDD, 96% line coverage". Regressions still ship weekly. You pull the history and a sample test file. Judge what the evidence actually proves.

Scoring: weighted decisions; the core diagnosis counts double.

// FIRST CONTACT

Battle teaser

First artifact

git log --oneline (excerpt)

What does the commit history tell you, and why does it matter?

  1. ATests were written a day after the implementation; test-after tests tend to mirror the code and pass by construction, locking in existing bugs as the spec
  2. BThe team squashed commits, which is the real problem
  3. CNothing; commit order never reflects how code was written
  4. DTDD was followed because tests exist at all
Answers, scoring, hints, and the full battle stay sealed.

// SKILL TAGS

tddcoveragemockstest-quality