Function callSource

packages/angular_devkit/schematics/src/rules/call.ts:49–63

(source: Source, context: SchematicContext)

}

export function callSource(source: Source, context: SchematicContext): Observable<Tree> {
  return defer(async () => {
    let result: Tree | Observable<Tree> | undefined = source(context);

    if (isObservable(result)) {
      result = await lastValueFrom(result.pipe(defaultIfEmpty(undefined)));
    }

    if (result && TreeSymbol in result) {
      return result;
    }

    throw new InvalidSourceResultException(result);
  });
}

export function callRule(
  rule: Rule,