rollup-plugin-coverage

0.1.4 verified Mon Apr 27 auth: no javascript deprecated

Rollup plugin for Istanbul unit test coverage. Version 0.1.4 provides integration with Istanbul instrumenter for code coverage reporting in Rollup and Karma. It offers options for include/exclude patterns, coverage options, and sourcemap support. The plugin is no longer actively maintained; users are advised to migrate to @rollup/plugin-istanbul or official Rollup coverage plugins.

Common errors

error Error: Cannot find module 'rollup-plugin-coverage' ↓

cause Package not installed or missing from node_modules.

fix

Run npm install rollup-plugin-coverage --save-dev

error TypeError: coverage is not a function ↓

cause Using named import instead of default import.

fix

Change import { coverage } to import coverage

Warnings

deprecated Package has not been updated since 2018 and is effectively deprecated. Use @rollup/plugin-istanbul instead. ↓

fix Replace with @rollup/plugin-istanbul: npm install @rollup/plugin-istanbul and update import.

gotcha Plugin must be placed before other plugins (like babel) to avoid instrumentation issues. ↓

fix Place coverage plugin first in the plugins array.

gotcha Coverage variable is not automatically captured in browser testing; requires manual extraction. ↓

fix Use Karma with karma-coverage for automatic browser coverage collection.

gotcha Sourcemap support requires setting sourceMapWithCode: true in coverageOptions. ↓

fix Add coverageOptions: { sourceMapWithCode: true }.

Install

npm install rollup-plugin-coverage

yarn add rollup-plugin-coverage

pnpm add rollup-plugin-coverage

Imports

default

wrong

const coverage = require('rollup-plugin-coverage')

correct

import coverage from 'rollup-plugin-coverage'

ESM default import; CJS require works but is not idiomatic for Rollup configs

coverage

wrong

import { coverage } from 'rollup-plugin-coverage'

correct

import coverage from 'rollup-plugin-coverage'

Package exports a default export only, not named.

coverage

wrong

const coverage = require('rollup-plugin-coverage')

correct

const coverage = require('rollup-plugin-coverage').default

CommonJS requires .default access due to ESM default export

Quickstart

Configures Rollup with Istanbul coverage, excluding test files and setting ES module instrumentation.

import { rollup } from 'rollup';
import coverage from 'rollup-plugin-coverage';

rollup({
  input: 'src/main.js',
  plugins: [
    coverage({
      exclude: ['test/**/*.js', 'node_modules/**'],
      coverageOptions: {
        esModules: true
      }
    })
  ]
}).then(bundle => bundle.write({ file: 'dist/bundle.js', format: 'es' }));