Function diagnosticToNode

packages/compiler-cli/src/ngtsc/testing/src/utils.ts:169–180

(
  diagnostic: ts.Diagnostic | ts.DiagnosticRelatedInformation,
  guard: (node: ts.Node) => node is T,
)

}

export function diagnosticToNode<T extends ts.Node>(
  diagnostic: ts.Diagnostic | ts.DiagnosticRelatedInformation,
  guard: (node: ts.Node) => node is T,
): T {
  const diag = diagnostic as ts.Diagnostic | ts.DiagnosticRelatedInformation;
  if (diag.file === undefined) {
    throw new Error(`Expected ts.Diagnostic to have a file source`);
  }
  const node = getTokenAtPosition(diag.file, diag.start!);
  expect(guard(node)).toBe(true);
  return node as T;
}