Registry / testing / karma-typescript-preprocessor

karma-typescript-preprocessor

library0.4.0jsnpmunverified

This package, `karma-typescript-preprocessor`, provides a Karma runner plugin designed to compile TypeScript files on the fly during unit testing. It integrates directly into the Karma configuration, allowing developers to test TypeScript code without a separate, explicit compilation step prior to running tests. The package is currently at version 0.4.0, with its last update occurring approximately seven years ago. Given its age, it is no longer actively maintained and may not support recent TypeScript versions or Karma features. While it offered configurable TypeScript compiler options like `target`, `module`, and `sourceMap` directly within `karma.conf.js`, its primary differentiator was simplifying test setups by handling TypeScript compilation internally, contrasting with the more feature-rich and actively maintained `karma-typescript` package which offers bundling, coverage remapping, and broader framework support.

testing

npm install karma-typescript-preprocessor

github ↗package ↗

INSTALL

IMPORT

SIG · KARMA-TYPESCRIPT-P

karma-typescript-preprocessor

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.

preprocessors configuration

✓ config.set({ preprocessors: { '**/*.ts': ['typescript'] } });

✗ import { TypescriptPreprocessor } from 'karma-typescript-preprocessor';

This package is a Karma plugin, configured in `karma.conf.js`. The preprocessor is referenced by its short name, 'typescript', not the full package name.

typescriptPreprocessor configuration object

✓ config.set({ typescriptPreprocessor: { options: { target: 'ES5' }, transformPath: function(path) { return path.replace(/\.ts$/, '.js'); } } });

This object holds compiler options and file transformation logic specific to the preprocessor.

Demonstrates a complete `karma.conf.js` setup for `karma-typescript-preprocessor`, including file patterns, preprocessor declaration, and custom TypeScript compiler options like `target` and `module`.

/** * karma.conf.js * Configuration for karma-typescript-preprocessor. */ module.exports = function(config) { config.set({ // Base path that will be used to resolve all relative paths for files and exclude. basePath: '', // Frameworks to use // available frameworks: https://npmjs.org/browse/keyword/karma-framework frameworks: ['jasmine'], // Example: using Jasmine testing framework // List of files / patterns to load in the browser files: [ 'src/**/*.ts', // Your TypeScript source files 'test/**/*.ts' // Your TypeScript test files ], // Preprocess matching files before serving them to the browser // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor preprocessors: { '**/*.ts': ['typescript'] }, // Configuration for the TypeScript preprocessor typescriptPreprocessor: { options: { sourceMap: true, // (optional) Generates corresponding .map file. target: 'ES5', // (optional) Specify ECMAScript target version: 'ES3' (default), or 'ES5' module: 'amd', // (optional) Specify module code generation: 'commonjs' or 'amd' noImplicitAny: true, // (optional) Warn on expressions and declarations with an implied 'any' type. removeComments: true // (optional) Do not emit comments to output. }, // Function to transform filenames, e.g., .ts to .js transformPath: function(path) { return path.replace(/\.ts$/, '.js'); } }, // Test results reporter to use // possible values: 'dots', 'progress' // available reporters: https://npmjs.org/browse/keyword/karma-reporter reporters: ['progress'], // Web server port port: 9876, // Enable / disable colors in the output (reporters and logs) colors: true, // Level of logging // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG logLevel: config.LOG_INFO, // Enable / disable watching file and executing tests whenever any file changes autoWatch: true, // Start these browsers // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher browsers: ['Chrome'], // Continuous Integration mode // if true, Karma captures browsers, runs the tests and exits singleRun: false, // Concurrency level // how many browser should be started simultaneous concurrency: Infinity }); };

Debug

Known issues

breakingThis package has been abandoned for approximately seven years and is no longer maintained. It will not support modern TypeScript features (e.g., decorators, newer ES versions, module resolution changes) or recent Karma versions, which itself has been deprecated. Using it with current ecosystems is likely to lead to compilation errors or unexpected behavior.

fix

Migrate to an actively maintained alternative like `karma-typescript` which provides broader support for modern TypeScript, bundling, and coverage.

affects: >=0.4.0

gotchaThe default TypeScript `target` is 'ES3', which is extremely outdated. If not explicitly configured, compiled output will be for an ancient JavaScript environment, potentially breaking modern code or tests.

fix

Always explicitly set the `target` option in `typescriptPreprocessor.options` to an appropriate modern ECMAScript version (e.g., 'ES2015', 'ESNext') that matches your project's requirements.

affects: >=0.1.0

gotchaSource maps are inlined as data-URIs when `sourceMap: true` is enabled. While convenient for simple debugging, this might increase file size or complicate integration with advanced debugging tools that expect external `.map` files.

fix

Be aware of the inlined source map behavior. For complex setups or specific debugging workflows, consider if `karma-typescript-preprocessor` is the right choice, as other preprocessors might offer external source map generation.

affects: >=0.1.0

breakingThe `module` option in `typescriptPreprocessor.options` defaults to `amd` if omitted. This assumes an AMD loader (like RequireJS) is present in your test environment. If your project uses CommonJS or ES Modules and no AMD loader, your tests will likely fail to load or execute.

fix

Set `module: 'commonjs'` or `module: 'esnext'` if your project or test environment uses those module systems. Ensure your Karma setup correctly handles module loading for the chosen option.

affects: >=0.1.0

gotchaAs an abandoned package, `karma-typescript-preprocessor` presents a supply chain security risk. It will not receive patches for newly discovered vulnerabilities in its own code or its transitive dependencies.

fix

Evaluate the risk and consider migrating to actively maintained alternatives. If continued use is unavoidable, ensure thorough security scanning of your project's dependencies.

affects: >=0.1.0

Errors

Common errors & fixes

ERROR [preprocessor]: Can not load "typescript" preprocessor!

The `karma-typescript-preprocessor` package or its dependency `typescript` is not installed, or Karma cannot find the preprocessor definition.

fix

Ensure `karma-typescript-preprocessor` is installed: `npm install --save-dev karma-typescript-preprocessor`. Also, verify that `typescript` is installed as a dependency (`npm install --save-dev typescript`). Check your `karma.conf.js` to confirm `preprocessors: { '**/*.ts': ['typescript'] }` is correctly configured.

TSxxxx: Cannot find name '...' / Property '...' does not exist on type '...'.

The TypeScript compiler version or configuration used by the preprocessor (version 0.4.0) is incompatible with your project's TypeScript code, or it's missing `@types` declarations. This preprocessor is very old and likely struggles with modern TS syntax or libraries.

fix

Review the `typescriptPreprocessor.options` in `karma.conf.js` to ensure `target`, `module`, and other compiler options align with your project. If using modern TypeScript, consider migrating to a more up-to-date Karma TypeScript preprocessor like `karma-typescript`.

ReferenceError: define is not defined / require is not defined

This error typically occurs when the `module` option in `typescriptPreprocessor.options` is set to `amd` or `commonjs` respectively, but the test environment (browser) lacks the corresponding module loader.

fix

If targeting browsers without a module loader, set `module: 'none'` or ensure an AMD/CommonJS loader (e.g., RequireJS for AMD, a bundler for CommonJS) is included in your Karma `files` array before your compiled test code.

Upgrade

Version history

0.4.0latest on npm

Audit

Dependencies

karmarequiredRuntime peer dependency; this package is a plugin for Karma.

typescriptrequiredRuntime peer dependency; required for TypeScript compilation.

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/sergeyt/karma-typescript-preprocessor ↗

packagehttps://www.npmjs.com/package/karma-typescript-preprocessor ↗