Node.js

Planned — not yet available

Node.js is on the nolapse roadmap as a P1 language. The built-in runner does not exist yet. The workaround below lets you use nolapse with Node.js projects today via the custom runner mechanism.

What is planned

When the built-in Node.js runner ships, it will:

• Accept lang: nodejs in nolapse.yaml.
• Invoke jest --coverage --coverageReporters=json-summary (or c8/v8 for non-Jest projects) automatically.
• Parse coverage-summary.json to extract the total statement coverage percentage.
• Respect the same warn_threshold / fail_threshold / strict_mode settings as all other runners.

The expected nolapse.yaml when it is available:

lang: nodejs
warn_threshold: -1.0
fail_threshold: -5.0
strict_mode: false

Workaround: custom runner

Until the built-in runner ships you can drive Jest coverage yourself and feed the result to nolapse via a custom runner script.

1. Generate a coverage summary

Add a script to package.json:

{
  "scripts": {
    "test:coverage": "jest --coverage --coverageReporters=json-summary --coverageDirectory=coverage"
  }
}

2. Write a custom runner script

Create nolapse-runner.sh at the repo root:

#!/usr/bin/env bash
set -euo pipefail

REPO_PATH="${1:-.}"
cd "$REPO_PATH"

npm test -- --coverage --coverageReporters=json-summary --coverageDirectory=coverage 2>/dev/null

PCT=$(node -e "
  const s = require('./coverage/coverage-summary.json');
  console.log(s.total.statements.pct);
")

echo "nolapse-coverage: ${PCT}"

Make it executable:

chmod +x nolapse-runner.sh

3. Configure nolapse

lang: custom
warn_threshold: -1.0
fail_threshold: -5.0

Point nolapse at the script:

NOLAPSE_RUNNER_PATH=./nolapse-runner.sh nolapse run --repo .

See Custom Runner for full details on the runner contract and the output format nolapse expects.

Track the roadmap

Watch the nolapse changelog and the Node.js runner issue for updates. When the built-in runner lands, you can remove the custom script and switch to lang: nodejs.