addInjector method
Returns a new instance of NgTestBed with the root injector wrapped.
That is, factory
will supplement the existing injector(s). In most
cases this is likely not required unless you are re-using test
configuration across many tests with subtle differences.
Implementation
NgTestBed<T> addInjector(InjectorFactory factory) {
return fork(
rootInjector: (Injector parent) => _rootInjector(factory(parent)),
);
}