assert.ts

/**
 * Asserts that a value is of a specific type.
 * If the assertion fails, an error is thrown.
 * 
 * @param value The value to type check (used only in type signature)
 * @param checker A function that returns true if the value is of the expected type
 * @param message Optional custom error message
 * @throws Error if the checker returns false
 */
export function assert<T>(
  value: unknown,
  checker: () => boolean,
  message?: string
): asserts value is T {
  if (!checker()) {
    throw new Error(message || `Type assertion failed: ${String(value)}`);
  }
}