TypeError: JSON.stringify cannot serialize cyclic structures

[ricazhang]

I'm submitting a bug report

Webpack version:
angular-cli version 1.6.1 which is using webpack ~3.10.0

Webpack Karma version:
see above

Karma version:
2.0.0

Please tell us about your environment:
Windows 7

Browser: PhantomJS 2.1.1
"karma-phantomjs-launcher": "1.0.4"

Current behavior:

• If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem along with a gist/jsbin of your webpack configuration.

I'm trying to run karma tests using angular cli and PhantomJS (ng test --code-coverage --single-run) but am getting an error which seems to be causing 24 out of my 33 unit tests to fail. When I run the tests with Chrome as the configured browser, all of the tests pass.

PhantomJS 2.1.1 (Windows 7.0.0) AppService should be created FAILED
    TypeError: JSON.stringify cannot serialize cyclic structures. in http://localhost:9876/_karma_webpack_/polyfills.bundle.js (line 5424)
    stringify@[native code]
    stringify@http://localhost:9876/_karma_webpack_/polyfills.bundle.js:5424:28
    displayModal@http://localhost:9876/_karma_webpack_/scripts.bundle.js:4473:57
    createModalContent@http://localhost:9876/_karma_webpack_/scripts.bundle.js:4453:41
    BMS@http://localhost:9876/_karma_webpack_/scripts.bundle.js:7282:43
    BMSService@http://localhost:9876/_karma_webpack_/main.bundle.js:2095:25930
    _createClass@http://localhost:9876/_karma_webpack_/vendor.bundle.js:84475:34
    _createProviderInstance$1@http://localhost:9876/_karma_webpack_/vendor.bundle.js:84447:38
    resolveNgModuleDep@http://localhost:9876/_karma_webpack_/vendor.bundle.js:84432:42
    _createClass@http://localhost:9876/_karma_webpack_
    ...(there was more in the stack but I cropped it)

In other issues people had with Karma and PhantomJS some suggested uncommenting the polyfills.ts file. I figured that might be related since the error seems to be coming from the polyfills bundled file so I tried running the tests with the polyfills commented out and also with them uncommented out and it didn't make a difference either way.

Here is my karma.conf.js file: http://plnkr.co/edit/SlYdbKzqddBwmdKNMK0U?p=catalogue

• What is the expected behavior?

Expected behavior should be the same as when I run the tests with Chrome as a browser which is that the tests should all pass.

• What is the motivation / use case for changing the behavior?

It doesn't work with PhantomJS. I previously posted a question on Stack Overflow and someone said this was a known issue but I didn't see any issues logged on this repo so I just wanted to check if it was known with this project.

[codymikol]

closing as this is an older ticket and the provided config does not seem to reference karma-webpack