improve-test-coverage

name	improve-test-coverage
description	This skill should be used when increasing test coverage to a specified threshold percentage. It runs the test suite with SimpleCov, identifies files with the lowest coverage, generates a brief with coverage gaps, and creates a plan with tasks to add the missing tests.
allowed-tools	["Read","Bash","Glob","Grep"]

Increase Test Coverage

Target threshold: $ARGUMENTS%

If no argument provided, prompt the user for a target.

Step 1: Gather Requirements

1. Find coverage config (.simplecov or spec/spec_helper.rb)
2. Run test suite with coverage to get current state:

   status=0
   bundle exec rspec >rspec.log 2>&1 || status=$?
   tail -n 50 rspec.log; echo "exit=$status"
   

   The status is captured before the pipe, because a pipeline reports its LAST stage's exit code — tail always succeeds, so a failing run reads as exit=0 (falsifiable-checks, pager-shadowed status). || status=$? rather than ; status=$?: under set -e the ; form exits before the assignment, so the failure is never reported at all.
3. Check SimpleCov output in coverage/index.html or console output
4. Identify the 20 files with lowest coverage, noting:
   • File path
   • Current coverage % (lines, branches)
   • Which lines/branches are uncovered

Step 2: Compile Brief and Delegate

Compile the gathered information into a structured brief:

Increase test coverage from [current]% to $ARGUMENTS%.

Files needing coverage (ordered by coverage gap):
1. [file] - [current]% coverage (target: $ARGUMENTS%)
   - Uncovered: [lines]
   - Missing branch coverage: [lines]
2. ...

Configuration: .simplecov, update minimum_coverage to $ARGUMENTS%

Verification: `bundle exec rspec` -> Expected: SimpleCov reports >= $ARGUMENTS% coverage

Invoke /implement with this brief to create the implementation plan.