Function expectTokenAtPosition

packages/compiler-cli/test/ngtsc/ngtsc_spec.ts:11812–11821

(
    sf: ts.SourceFile,
    pos: number,
    guard: (node: ts.Node) => node is T,
  )

  });

  function expectTokenAtPosition<T extends ts.Node>(
    sf: ts.SourceFile,
    pos: number,
    guard: (node: ts.Node) => node is T,
  ): T {
    // getTokenAtPosition is part of TypeScript's private API.
    const node = (ts as any).getTokenAtPosition(sf, pos) as ts.Node;
    expect(guard(node)).toBe(true);
    return node as T;
  }
});