mock-data.module.ts

//...}

@NgModule({
  imports: [BrowserModule],
  declarations: [MockData],
  providers: [
    { provide: ListsService, useFactory: ListsServiceFactory }
  ],
  entryComponents: [MockData]
})
export class MockDataModule {
  ngDoBootstrap(){}
}

/**
 * Lists Service Factory that provides the right service based on the context of the running WebPart
 */
export function ListsServiceFactory() {
  if (Environment.type === EnvironmentType.Local) {
    return new MockListsService();
  } else if (Environment.type == EnvironmentType.SharePoint || Environment.type == EnvironmentType.ClassicSharePoint) {
    return new ListsService();
  }
};

https://gist.github.com/sebastienlevert/d678b633888625a6e64fb2b147aa2419#file-mock-data-module-ts-L21 should be replaced by Environment.type === EnvironmentType.SharePoint || Environment.type === EnvironmentType.ClassicSharePoint to avoid lint errors

https://gist.github.com/sebastienlevert/d678b633888625a6e64fb2b147aa2419#file-mock-data-module-ts-L19 should be replaced by if (Environment.type === EnvironmentType.Local || Environment.type === EnvironmentType.Test) { to cover all case and support unit tests