Karma: Karma error after update to version 6.0.0

[SymbioticKilla]

Hi,

I get following error after update:

ERROR [karma-server]: Server start failed on port 9876: Error: No provider for "customFileHandlers"! (Resolving: framework:@angular-devkit/build-angular -> customFileHandlers)   
ERROR [karma-server]: Error while calling exit event listeners
TypeError: Cannot read property 'name' of undefined
    at TfsReporter.onExit (C:\Dev\***\spa\node_modules\karma-tfs-reporter\index.js:53:38)
    at Server.<anonymous> (C:\Dev\***\spa\node_modules\karma\lib\events.js:40:26)
    at Server.emit (events.js:327:22)
    at Server.emitExitAsync (C:\Dev\***\spa\node_modules\karma\lib\server.js:146:12)
    at Server._close (C:\Dev\***\spa\node_modules\karma\lib\server.js:413:10)
    at Server.start (C:\Dev\***\spa\node_modules\karma\lib\server.js:120:12)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)

[alecgibson]

~This is probably a karma-webpack issue: https://github.com/ryanclark/karma-webpack/issues/462~

(Sorry skim-read the stack)

[devoto13]

Note that 6.0.0 is a major release, which has breaking changes. It is not compatible with the current release of @angular-devkit/build-angular package, hence the error. You should have received a warning about incompatible peer dependency from NPM when you updated to it.

The support for Karma 6.0.0 has already been added to Angular CLI (https://github.com/angular/angular-cli/pull/19784) and will probably be released in 11.1.0. Until then, please stick with Karma 5.x.

[SymbioticKilla]

@devoto13 Thanks! Will it be back ported to 10.2?

[devoto13]

I don’t think so. AFAIK only critical fixes get backported.

[SymbioticKilla]

@devoto13 =( Is it possible to back port CVE Fixes to Karma 5 then?

[devoto13]

Unfortunately we don't have a process to backport changes at the moment... I guess we can either try to make a patch release on 5.x branch or restore customFileHandlers provider with the deprecation warning on the 6.x branch (so people can use Karma 6.x with older Angular CLI with the peer dependency warning).

@johnjbarton Which option do you think is better?