Registry / testing / karma-sourcemap-loader

karma-sourcemap-loader

library0.4.0jsnpmunverified

A Karma plugin preprocessor that loads existing JavaScript source map files (both inline and external) into the Karma test runner. Version 0.4.0 is current stable. Unlike karma-sourcemap-preprocessor, this plugin does not generate source maps but locates them from previous build steps (e.g., TypeScript, Babel, webpack). It supports remapping source paths via prefix replacement or custom callback, and modifying sourceRoot. Inline source maps using base64 are also supported. Release cadence is low, primarily maintenance updates. Key differentiator: solves source map loading when compilation happens outside Karma.

testing

npm install karma-sourcemap-loader

github ↗package ↗

INSTALL

IMPORT

SIG · KARMA-SOURCEMAP-LO

karma-sourcemap-loader

testingjavascriptv0.4.0

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.

sourcemap

✓ preprocessors: { '**/*.js': ['sourcemap'] }

✗ preprocessors: { '**/*.js': ['karma-sourcemap-loader'] }

The preprocessor name is 'sourcemap', not the package name.

sourceMapLoader

✓ config.set({ sourceMapLoader: { ... } })

✗ config.set({ sourcemapLoader: { ... } })

Configuration key must use camelCase: sourceMapLoader (capital M) in karma.conf.js.

remapPrefixes

✓ sourceMapLoader: { remapPrefixes: { '/myproject/': '../src/' } }

✗ sourceMapLoader: { remap: { '/myproject/': '../src/' } }

The exact key is 'remapPrefixes', not 'remap' or 'prefixes'.

Configures Karma to load existing source maps for all JS files, remapping paths with a prefix.

// karma.conf.js module.exports = function(config) { config.set({ basePath: '', frameworks: ['jasmine'], files: ['src/**/*.js', 'test/**/*.spec.js'], preprocessors: { '**/*.js': ['sourcemap'] }, sourceMapLoader: { remapPrefixes: { '/myproject/': '../src/' } }, browsers: ['ChromeHeadless'], singleRun: true }); };

Debug

Known issues

gotchaPreprocessor name is 'sourcemap' not 'karma-sourcemap-loader'.

fix

Use 'sourcemap' as the preprocessor name in preprocessors config.

affects: >=0.2.0

gotchaConfiguration key is 'sourceMapLoader' (camelCase) not 'sourcemaploader' or 'source-map-loader'.

fix

Use 'sourceMapLoader' in config.set().

affects: >=0.3.0

breakingRemoved Node.js < 10 support. Graceful-fs usage may break on older Node.

fix

Upgrade Node.js to version 10 or later.

affects: >=0.4.0

deprecatedThe 'remapSource' callback function may be deprecated in future versions; prefer 'remapPrefixes'.

fix

Use 'remapPrefixes' object instead of 'remapSource' function if possible.

affects: >=0.4.0

Errors

Common errors & fixes

Error: No provider for "sourcemap"! (Resolving: sourcemap)

Preprocessor name 'sourcemap' is misspelled or not configured correctly.

fix

Ensure preprocessors config uses 'sourcemap' exactly, e.g., preprocessors: { '**/*.js': ['sourcemap'] }.

ReferenceError: module is not defined in ES module scope

Using CommonJS module.exports in an ESM project (package.json type: module).

fix

Rename file to .cjs or use export default or dynamic import() for ES modules.

Upgrade

Version history

0.4.0latest on npm

Audit

Dependencies

graceful-fsrequiredUsed for filesystem operations to load source map files

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/demerzel3/karma-sourcemap-loader ↗

packagehttps://www.npmjs.com/package/karma-sourcemap-loader ↗