How do I turn off source maps for Angular 6 ng test?

You can use

CLI v6.0.8 and above --source-map=false

CLI v6.x --sourceMap=false

CLI v1.x --sourcemaps=false

Angular CLI v6.x reads --source-map as --sourceMap. So both --source-map and --sourceMap works for me for CLI v6.0.8

Go to package.json Change "test":"ng test" to "test":"ng test --source-map=false" to turn off sourcemaps.

Please note it shoud be --source-map and not --source-maps.

Angular CLI changing this param from version to version as per this answer:

CLI v6.0.8 and above
--source-map=false

CLI v6.0.x early versions
--sourceMap=false

CLI v1.x
--sourcemaps=false

Shortcut ng test -sm=false might also work

In case if you are on the latest CLI and none of above works you can always check the Options section at https://github.com/angular/angular-cli/blob/master/docs/documentation/test.md for the recent param name