Function assert

packages/compiler-cli/linker/src/ast/utils.ts:13–21

(
  node: T,
  predicate: (node: T) => node is K,
  expected: string,
)

 * Assert that the given `node` is of the type guarded by the `predicate` function.
 */
export function assert<T, K extends T>(
  node: T,
  predicate: (node: T) => node is K,
  expected: string,
): asserts node is K {
  if (!predicate(node)) {
    throw new FatalLinkerError(node, `Unsupported syntax, expected ${expected}.`);
  }
}