faster-babel-types/src/assert-node-type.ts

Faster `@babel/types`

import type * as t from '@babel/types';
import { either, is } from './is-node-type';

// https://github.com/babel/babel/blob/dba45d3ebc92a868c9b8952a6f407c6ab83c6b3f/packages/babel-types/src/asserts/generated/index.ts#L9
export function assert<
  T extends t.Node['type'],
  P extends Extract<
    t.Node,
    {
      type: T;
    }
  >,
>(type: T, node: t.Node | null | undefined): asserts node is P {
  if (is(type, node)) {
    throw new Error(
      'Expected type "' + type + '" but instead got "' + node.type + '".',
    );
  }
}

export function assertEither<
  T extends t.Node['type'],
  P extends Extract<
    t.Node,
    {
      type: T;
    }
  >,
>(
  name: string,
  types: Set<T>,
  node: t.Node | null | undefined,
): asserts node is P {
  if (either(types, node)) {
    throw new Error(
      'Expected type "' + name + '" but instead got "' + node.type + '".',
    );
  }
}