Function internalImportProvidersFrom

packages/core/src/di/provider_collection.ts:151–189

(
  checkForStandaloneCmp: boolean,
  ...sources: (ImportProvidersSource | AbstractType<unknown>)[]
)

}

export function internalImportProvidersFrom(
  checkForStandaloneCmp: boolean,
  ...sources: (ImportProvidersSource | AbstractType<unknown>)[]
): Provider[] {
  const providersOut: SingleProvider[] = [];
  const dedup = new Set<Type<unknown> | AbstractType<unknown>>(); // already seen types
  let injectorTypesWithProviders: InjectorTypeWithProviders<unknown>[] | undefined;

  const collectProviders: WalkProviderTreeVisitor = (provider) => {
    providersOut.push(provider);
  };

  deepForEach(sources, (source) => {
    if ((typeof ngDevMode === 'undefined' || ngDevMode) && checkForStandaloneCmp) {
      const cmpDef = getComponentDef(source);
      if (cmpDef?.standalone) {
        throw new RuntimeError(
          RuntimeErrorCode.IMPORT_PROVIDERS_FROM_STANDALONE,
          `Importing providers supports NgModule or ModuleWithProviders but got a standalone component "${stringifyForError(
            source,
          )}"`,
        );
      }
    }

    // Narrow `source` to access the internal type analogue for `ModuleWithProviders`.
    const internalSource = source as Type<unknown> | InjectorTypeWithProviders<unknown>;
    if (walkProviderTree(internalSource, collectProviders, [], dedup)) {
      injectorTypesWithProviders ||= [];
      injectorTypesWithProviders.push(internalSource);
    }
  });
  // Collect all providers from `ModuleWithProviders` types.
  if (injectorTypesWithProviders !== undefined) {
    processInjectorTypesWithProviders(injectorTypesWithProviders, collectProviders);
  }

  return providersOut;
}

/**
 * Collects all providers from the list of `ModuleWithProviders` and appends them to the provided