bun-test-coverage

Bun 测试覆盖率

Bun 内置代码覆盖率报告，无需额外依赖。

启用覆盖率

# Enable coverage
bun test --coverage

# With threshold (fail if below)
bun test --coverage --coverage-threshold 80

在 bunfig.toml 中配置

[test]
coverage = true
coverageThreshold = 0.8  # 80% minimum
coverageDir = "./coverage"

# Patterns to ignore
coverageSkipTestFiles = true

覆盖率输出

------------------|---------|---------|-------------------
File              | % Funcs | % Lines | Uncovered Line #s
------------------|---------|---------|-------------------
All files         |   85.71 |   89.23 |
 src/index.ts     |  100.00 |  100.00 |
 src/utils.ts     |   75.00 |   82.35 | 23-25, 41-43
 src/api.ts       |   80.00 |   85.00 | 67, 89-92
------------------|---------|---------|-------------------

覆盖率报告器

# Default console output
bun test --coverage

# Generate lcov report
bun test --coverage --coverage-reporter=lcov

# Multiple reporters
bun test --coverage --coverage-reporter=text --coverage-reporter=lcov

可用的报告器

报告器	输出
text	控制台表格（默认）
lcov	供 CI 工具使用的 coverage/lcov.info
json	coverage/coverage.json

覆盖率阈值

设置最低覆盖率要求：

# Fail if coverage < 80%
bun test --coverage --coverage-threshold 80

# Per-metric thresholds in bunfig.toml

[test]
coverage = true
coverageThreshold = {
  lines = 80,
  functions = 75,
  branches = 70
}

排除文件

[test]
coverage = true

# Skip test files from coverage
coverageSkipTestFiles = true

# Patterns to exclude
coverageIgnore = [
  "**/*.test.ts",
  "**/fixtures/**",
  "**/mocks/**"
]

CI 集成

GitHub Actions

- name: Run tests with coverage
  run: bun test --coverage --coverage-reporter=lcov

- name: Upload coverage to Codecov
  uses: codecov/codecov-action@v5
  with:
    files: ./coverage/lcov.info

输出目录

# Custom output directory
bun test --coverage --coverage-dir=./reports/coverage

编程方式获取覆盖率

import { test, expect } from "bun:test";

// Get coverage data programmatically
const coverage = Bun.coverage;

// Access after tests complete
process.on("exit", () => {
  console.log(coverage.getCoverageData());
});

常见错误

错误	原因	修复方法
Coverage threshold not met	覆盖率低于阈值	提高测试覆盖率
No coverage data	未执行文件	检查测试是否包含该文件
lcov not found	缺少报告器	添加 --coverage-reporter=lcov

最佳实践

1. 设置切合实际的阈值 - 从 60% 开始，逐步提高
2. 排除生成的文件 - 模拟文件、类型定义
3. 关注关键路径 - 优先覆盖业务逻辑，而非样板代码
4. 在 CI 中运行 - 防止覆盖率回退

何时加载参考资料

在以下情况下加载 references/reporters.md：

• 自定义报告器配置
• CI/CD 集成详情
• Codecov/Coveralls 设置