There seems to be no easy way to do this.
Although you could specify custom launch options for Chromium, there is no option that controls the position of devtool. (Although there are --auto-open-devtools-for-tabs , which may also be convenient in your case.)
However, there is a good hack described in the related issue :
The brute force approach should pass the --user-data-dir flag to the custom launcher:
browsers: ['Chrome'], customLaunchers: { Chrome_DevTools_Saved_Prefs: { base: 'Chrome', flags: ['--user-data-dir=./tests/config/.chrome_dev_user'] } }
then
karma start
This will allow you to reuse your profile. If you want to test using the new profile, use the standard Chrome launchpad or destroy the user data directory.
UPDATE : as @KFunk points out, this case is best described in the Karma documentation :
customLaunchers: { Chrome_with_debugging: { base: 'Chrome', chromeDataDir: path.resolve(__dirname, '.chrome') } }
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