With the latest CLI, inside angular.json
"test": {
"builder": "@angular-devkit/build-angular:karma",
"options": {
"main": "src/test.ts",
"polyfills": "src/polyfills.ts",
"tsConfig": "src/tsconfig.spec.json",
"karmaConfig": "./karma.conf.js",
"codeCoverageExclude": ["src/testing/**/*"],