@ardatan/relay-compiler/util/orList.js.flow

A compiler tool for building GraphQL-driven applications.

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow strict
 * @format
 */

// flowlint ambiguous-object-type:error

'use strict';

const OR_LIST_MAX_LENGTH = 5;

const {createCompilerError} = require('../core/CompilerError');

function orList(items: $ReadOnlyArray<string>): string {
  if (items.length === 0) {
    throw createCompilerError('Expected an array of strings. Got empty array');
  }

  if (items.length === 1) {
    return items[0];
  }

  if (items.length > OR_LIST_MAX_LENGTH) {
    return items.slice(0, OR_LIST_MAX_LENGTH).join(', ') + ', ...';
  }

  const selected = items.slice();
  const lastItem = selected.pop();
  return selected.join(', ') + ' or ' + lastItem;
}

module.exports = orList;