Registry / testing / one-double-zero-core

one-double-zero-core

library1.0.2jsnpmunverified

A code coverage API for JavaScript aiming at relevance, accuracy, simplicity, flexibility and speed (v1.0.2). It leverages V8's built-in coverage for fast, accurate results without instrumenting code. The API is designed to be minimal and composable, catering to both programmatic use and integration with test runners. Ships TypeScript types. Released under ISC license. Known for being lighter and faster than c8 or Istanbul, but with a different API paradigm.

testing

npm install one-double-zero-core

package ↗homepage ↗

INSTALL

IMPORT

SIG · ONE-DOUBLE-ZERO-CO

one-double-zero-core

testingjavascriptv1.0.2

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ import oneDoubleZeroCore from 'one-double-zero-core'

✗ import { oneDoubleZeroCore } from 'one-double-zero-core'

Module provides a default export, not named exports.

Coverage

✓ import { Coverage } from 'one-double-zero-core'

✗ import Coverage from 'one-double-zero-core'

Coverage is a named export; do not use default import for it.

Instrumenter

✓ import { Instrumenter } from 'one-double-zero-core'

✗ import Instrumenter from 'one-double-zero-core'

Instrumenter is a named export.

commonjs require

✓ const oneDoubleZeroCore = require('one-double-zero-core')

✗ const { oneDoubleZeroCore } = require('one-double-zero-core')

CJS users must require the default export; destructing works but only for named exports which are also available.

Shows basic usage: initialize coverage with include/exclude patterns, then take snapshot after tests.

import coverage from 'one-double-zero-core'; const { Coverage } = await coverage.load({ // Paths to cover, e.g., 'src/**/*.js' include: ['src/**/*.js'], // Exclude patterns exclude: ['node_modules'] }); // After your tests run, gather coverage data const result = await Coverage.takeSnapshot(); console.log('Coverage percentage:', result.summary.coveredLines / result.summary.totalLines * 100);

Debug

Known issues

breakingAPI differs from c8/istanbul; no automatic instrumenter.

fix

Use explicit Coverage and Instrumenter classes; refer to docs for programmatic usage.

affects: >=1.0.0

gotchaMust call coverage.load() before tests; otherwise snapshot returns empty.

fix

Always await coverage.load() at the start of your test setup.

affects: >=1.0.0

gotchaExcludes 'node_modules' by default; override if needed.

fix

Set exclude: [] to include node_modules (not recommended).

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: (0 , _oneDoubleZeroCore.default) is not a function

Using default import incorrectly in TypeScript or Babel when module is CJS?

fix

Ensure you use import coverage from 'one-double-zero-core' with ESM and appropriate tsconfig (esModuleInterop: true).

Error: ENOENT: no such file or directory, open 'path/to/coverage.json'

Forgetting to provide output path or calling snapshot before load.

fix

Check that coverage.load() was awaited and options are correct.

Upgrade

Version history

1.0.2latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

4 hits · last 30 days

node

Resources

packagehttps://www.npmjs.com/package/one-double-zero-core ↗

homepagehttps://one-double-zero.nightlycommit.com ↗