coverage-node

A simple CLI to run Node.js and report code coverage.

• ✨ Zero config.
• 🏁 Tiny SLOC, written from scratch to use code coverage features built into Node.js v10+.
• 📦 Lean install size, compared to 2.2 MB for c8 v7.7.1 or 8.84 MB for nyc v15.1.0.
• 🖱 Displays ignored or uncovered source code ranges as paths, clickable in IDEs such as VS Code.

Installation

To install with npm, run:

npm install coverage-node --save-dev

In a package.json script, replace the node command with coverage-node:

 {
   "scripts": {
-    "test": "node test.mjs"
+    "test": "coverage-node test.mjs"
   }
 }

Requirements

• Operating system:
  • Linux
  • macOS
• Node.js: ^12.22.0 || ^14.17.0 || >= 16.0.0, but for Node.js versions < v13.3 that produce unreliable coverage data the command coverage-node skips code coverage and logs a warning.

Ignored files

Code coverage analysis ignores:

• node_modules directory files, e.g. node_modules/foo/index.mjs.
• test directory files, e.g. test/index.mjs.
• Files with .test prefixed before the extension, e.g. foo.test.mjs.
• Files named test (regardless of extension), e.g. test.mjs.

Ignored lines

In source code, a comment (case insensitive) can be used to ignore code coverage ranges that start on the the next line:

// coverage ignore next line
if (false) console.log("Never runs.");

CLI

Command coverage-node

Substitutes the normal node command; any node CLI options can be used to run a test script. If the script doesn’t error a code coverage analysis is reported to the console, and if coverage is incomplete the exit code is 1.

Examples

npx can be used to quickly check code coverage for a script:

npx coverage-node test.mjs

A package.json script:

{
  "scripts": {
    "test": "coverage-node test.mjs"
  }
}

Exports

These ECMAScript modules are published to npm and exported via the package.json exports field:

• analyseCoverage.mjs
• coverageSupported.mjs
• coverageSupportedMinNodeVersion.mjs
• reportCoverage.mjs