AgentSkillsCN

code-coverage-analysis

针对 One By Two 应用，提供分析与提升测试代码覆盖率的指南。当被问及代码覆盖率、覆盖率报告，或寻找未被测试的代码路径时，可使用此指南。

SKILL.md
--- frontmatter
name: code-coverage-analysis
description: Guide for analyzing and improving test code coverage in the One By Two app. Use this when asked about code coverage, coverage reports, or finding untested code paths.

Generating Coverage Reports

Flutter (Dart)

bash
# Run tests with coverage
flutter test --coverage

# Generate HTML report (requires lcov)
genhtml coverage/lcov.info -o coverage/html
open coverage/html/index.html

# Check coverage percentage
lcov --summary coverage/lcov.info

Cloud Functions (TypeScript)

bash
cd functions
npx jest --coverage
# Report generated in functions/coverage/

Coverage Targets

LayerTargetRationale
Domain entities & value objects95%+Core business logic, must be bulletproof
Use cases90%+Business workflows, critical paths
Algorithms (split, debt simplify)100%Money calculations, zero tolerance for bugs
Data mappers90%+Data transformation correctness
DAOs80%+Database operations
Repositories80%+Integration of local + remote
Widgets70%+UI component rendering
Providers80%+State management logic
Cloud Functions85%+Server-side business logic
Firestore rules100% of rulesEvery rule path tested positive + negative

Finding Uncovered Code

After generating coverage, analyze the LCOV report to find gaps:

bash
# List files with coverage below 80%
lcov --summary coverage/lcov.info 2>&1 | grep -E "^\s+\S+.*[0-7][0-9]\.[0-9]%"

# Or parse the lcov.info file
grep -E "^SF:|^LH:|^LF:" coverage/lcov.info | paste - - - | awk -F'[:|]' '{
  file=$2; hit=$4; total=$6;
  pct=(total>0) ? (hit/total*100) : 100;
  if (pct < 80) printf "%5.1f%% %s\n", pct, file
}' | sort -n

Improving Coverage Strategy

  1. •Start with algorithms — They handle money. 100% coverage, no exceptions.
  2. •Cover error paths — Test what happens when DB writes fail, network is down, validation rejects input.
  3. •Cover edge cases — Empty lists, zero amounts, single participant, 100 members.
  4. •Cover offline paths — Save while offline, sync on reconnect, conflict resolution.
  5. •Don't chase vanity coverage — 80% of meaningful code > 100% of trivial code.

Excluding from Coverage

Some files are legitimately excluded from coverage targets:

  • •Generated code (*.g.dart, *.freezed.dart)
  • •Firebase options (firebase_options.dart)
  • •Main entry point (main.dart)
  • •Route definitions (app_router.dart)

Add to lcov.info filtering:

bash
lcov --remove coverage/lcov.info \
  '**/*.g.dart' \
  '**/*.freezed.dart' \
  '**/firebase_options.dart' \
  -o coverage/lcov_filtered.info