角度的业力不会导入pixelmatch

Question

I use pixelmatch to test canvas elements. While importing pixelmatch in a component file works fine, karma won't import it in a spec file.

To reproduce the error:

ng new someproject
cd someproject
npm install pixelmatch @types/pixelmatch

Change

export = Pixelmatch

to

export default Pixelmatch 

in 'node_modules/@types/pixelmatch/index.d.ts'

Since I'm still new to typescript I can't explain why it is needed but without it importing Pixelmatch is not working at all. Perhaps this is causing problems to karma.

I also install karma-firefox-launcher and change karma.conf.js to run tests in firefox.

Now

import Pixelmatch from 'pixelmatch'

in app.component.ts works fine, but the same import in app.component.spec.ts doesn't .

expect(Pixelmatch).not.toBe(undefined) 

is not passing.

I'd be grateful for some hints.

Answer 1

Try

import Pixelmatch = require('pixelmatch')

For my NodeJS aplication with CommonJS syntax, it works like a charm!