Registry / testing / karma-typescript-preprocessor2

karma-typescript-preprocessor2

library1.2.1jsnpmunverified

A Karma preprocessor plugin that transpiles TypeScript files using the gulp-typescript compiler with incremental compilation for fast rebuilds. Version 1.2.1 is the latest stable release. It relies on tsconfig.json for primary configuration, supports custom compiler overrides, sourcemaps via gulp-sourcemaps, and virtual path transformations. Notable features include very fast incremental rebuilds, good error reporting, and the ability to exclude .d.ts files. However, it has several unsupported TypeScript config options (sourceMap, rootDir, watch, project) and may face compatibility issues with newer Karma or TypeScript versions.

testing

npm install karma-typescript-preprocessor2

github ↗package ↗

INSTALL

IMPORT

SIG · KARMA-TYPESCRIPT-P

karma-typescript-preprocessor2

testingjavascriptv1.2.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

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

default

✓ // Add 'typescript' to karma preprocessors list in karma.conf.js

✗ npm install karma-typescript-preprocessor (without 2)

This is a Karma plugin, not imported in code. It is loaded by Karma when listed in preprocessors.

typescriptPreprocessor config

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

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

Configuration is placed in karma.conf.js under 'typescriptPreprocessor' key.

transformPath

✓ config.set({ typescriptPreprocessor: { transformPath: [function(path){ ... }] } })

✗ config.set({ transformPath: ... })

transformPath is an array of functions inside typescriptPreprocessor.

Configures Karma to preprocess TypeScript files with this plugin. Includes tsconfig.json reference, sourcemap generation, and path transformation.

// karma.conf.js module.exports = function(config) { config.set({ basePath: '', frameworks: ['jasmine'], files: [ 'src/**/*.ts', 'test/**/*.spec.ts' ], preprocessors: { '**/*.ts': ['typescript', 'sourcemap'] }, typescriptPreprocessor: { tsconfigPath: './tsconfig.json', compilerOptions: { module: 'commonjs', target: 'es5' }, sourcemapOptions: { includeContent: true, sourceRoot: '/src' }, transformPath: [function(path) { return path.replace(/\.ts$/, '.js'); }] }, reporters: ['progress'], port: 9876, colors: true, logLevel: config.LOG_INFO, autoWatch: true, browsers: ['ChromeHeadless'], singleRun: false }); };

Debug

Known issues

deprecatedUnsupported TypeScript config options: sourceMap, inlineSources, sourceRoot, rootDir, watch, project

fix

Use compilerOptions in typescriptPreprocessor to override, but avoid those keys. Use gulp.src base option instead of rootDir. Set singleRun: false for watch.

affects: >=1.0.0

gotchaThe tsconfigPath option is obligatory; without it the plugin will fail.

fix

Ensure tsconfig.json exists and path is correct relative to Karma basePath.

affects: >=1.0.0

gotchatransformPath default replaces .ts with .js; if you override, you must include that transformation or files won't be served.

fix

Always include a transform that changes .ts to .js in your transformPath array.

affects: >=1.0.0

breakingPlugin only works with gulp-typescript; it does not use the official TypeScript compiler API.

fix

If you need different TypeScript features, use karma-typescript or karma-webpack instead.

affects: >=1.0.0

Errors

Common errors & fixes

Error: Preprocessor 'typescript' is not registered! (or similar)

Plugin not installed or not listed in karma.conf.js preprocessors.

fix

Run `npm install karma-typescript-preprocessor2 --save-dev` and ensure preprocessors config has 'typescript'.

TypeError: Cannot read property 'tsconfigPath' of undefined

typescriptPreprocessor config block missing in karma.conf.js.

fix

Add `typescriptPreprocessor: { tsconfigPath: './tsconfig.json' }` to config.set().

Unhandled rejection: Error: Could not find any TypeScript compiler. Did you install gulp-typescript?

gulp-typescript peer dependency missing.

fix

Run `npm install gulp-typescript --save-dev`.

TypeError: path.replace is not a function

transformPath item is not a function or array.

fix

Ensure transformPath is an array of functions, e.g., `transformPath: [function(path) { return path.replace(/\.ts$/, '.js'); }]`.

Upgrade

Version history

1.2.1latest on npm

Audit

Dependencies

gulp-typescriptrequiredCore transpiler dependency

gulp-sourcemapsoptionalRequired for generating sourcemaps

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/klaygomes/karma-typescript-preprocessor2 ↗

packagehttps://www.npmjs.com/package/karma-typescript-preprocessor2 ↗