Code Coverage

$ bun test --coverage

---------------|---------|---------|-------------------
File           | % Funcs | % Lines | Uncovered Line #s
---------------|---------|---------|-------------------
All files      |   85.71 |   88.89 |
 math.ts        |  100.00 |  100.00 |
 utils.ts       |   75.00 |   83.33 | 12-15, 23
---------------|---------|---------|-------------------

$ bun test --coverage --coverage-reporter text

$ bun test --coverage --coverage-reporter lcov

$ bun test --coverage --coverage-reporter text --coverage-reporter lcov

$ bun test --coverage --coverage-dir my-coverage

[test]
coverageReporter = ["text", "lcov"]
coverageDir = "./coverage"
coverageSkipTestFiles = true

[test]
coverageSkipTestFiles = true

[test]
coveragePathIgnorePatterns = [
  "node_modules",
  "*.config.ts",
  "test/fixtures",
  "**/*.mock.ts"
]

[test.coverageThreshold]
line = 80
function = 80
statement = 80
branch = 80

$ bun test --coverage
Error: Coverage for lines (75%) does not meet threshold (80%)

$ bun test --coverage --coverage-reporter lcov
$ genhtml coverage/lcov.info -o coverage/html
$ open coverage/html/index.html

function add(a: number, b: number) {
  return a + b; // Covered if function is called
}

function used() {
  return 1; // Covered
}

function unused() {
  return 2; // Not covered
}

used();

function check(x: number) {
  if (x > 0) {
    return "positive"; // Branch 1
  } else {
    return "negative"; // Branch 2
  }
}

check(5); // Only branch 1 covered

const x = 1; // Statement 1 - covered
const y = 2; // Statement 2 - covered
const z = 3; // Statement 3 - not covered if return happens before

utils.ts       |   75.00 |   83.33 | 12-15, 23

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

function divide(a: number, b: number) {
  if (b === 0) {
    throw new Error("Division by zero");
  }
  return a / b;
}

test("divide - normal case", () => {
  expect(divide(10, 2)).toBe(5);
});

// Add test for error branch
test("divide - by zero", () => {
  expect(() => divide(10, 0)).toThrow("Division by zero");
});

[test.coverageThreshold]
line = 80
function = 80

name: Test with Coverage

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: oven-sh/setup-bun@v1
      
      - run: bun install
      - run: bun test --coverage --coverage-reporter lcov
      
      - name: Upload coverage to Codecov
        uses: codecov/codecov-action@v3
        with:
          files: ./coverage/lcov.info

test:
  script:
    - bun install
    - bun test --coverage --coverage-reporter lcov
  coverage: '/All files[^|]*\|[^|]*\s+([\d\.]+)/'
  artifacts:
    reports:
      coverage_report:
        coverage_format: cobertura
        path: coverage/lcov.info

[test]
coveragePathIgnorePatterns = ["generated/", "*.g.ts"]

# Before committing
$ bun test --coverage

$ bun test --coverage

$ rm -rf coverage/
$ bun test --coverage

[test]
coveragePathIgnorePatterns = ["node_modules/**", "test/**"]