@react-native-firebase/firestore/lib/FirestoreBlob.js

React Native Firebase - Cloud Firestore is a NoSQL cloud database to store and sync data between your React Native application and Firebase's database. The API matches the Firebase Web SDK whilst taking advantage of the native SDKs performance and offline

/*
 * Copyright (c) 2016-present Invertase Limited & Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this library except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

import { Base64, isString } from '@react-native-firebase/app/lib/common';

export default class FirestoreBlob {
  constructor(internal = false, binaryString = undefined) {
    if (internal === false) {
      throw new Error(
        'firebase.firestore.Blob constructor is private, use Blob.<field>() instead.',
      );
    }

    this._binaryString = binaryString;
  }

  /**
   * Creates a new Blob from the given Base64 string
   *
   * @url https://firebase.google.com/docs/reference/js/firebase.firestore.Blob#.fromBase64String
   * @param base64 string
   */
  static fromBase64String(base64) {
    if (!isString(base64) || base64.length < 1) {
      throw new Error(
        'firestore.Blob.fromBase64String expects a string of at least 1 character in length',
      );
    }

    return new FirestoreBlob(true, Base64.atob(base64));
  }

  /**
   * Creates a new Blob from the given Uint8Array.
   *
   * @url https://firebase.google.com/docs/reference/js/firebase.firestore.Blob#.fromUint8Array
   * @param array Array
   */
  static fromUint8Array(array) {
    if (!(array instanceof Uint8Array)) {
      throw new Error('firestore.Blob.fromUint8Array expects an instance of Uint8Array');
    }

    return new FirestoreBlob(
      true,
      Array.prototype.map.call(array, $ => String.fromCharCode($)).join(''),
    );
  }

  /**
   * Returns 'true' if this Blob is equal to the provided one.
   * @url https://firebase.google.com/docs/reference/js/firebase.firestore.Blob#isEqual
   * @param {*} blob Blob The Blob to compare against. Value must not be null.
   * @returns boolean 'true' if this Blob is equal to the provided one.
   */
  isEqual(blob) {
    if (!(blob instanceof FirestoreBlob)) {
      throw new Error('firestore.Blob.isEqual expects an instance of Blob');
    }

    return this._binaryString === blob._binaryString;
  }

  /**
   * Returns the bytes of a Blob as a Base64-encoded string.
   *
   * @url https://firebase.google.com/docs/reference/js/firebase.firestore.Blob#toBase64
   * @returns string The Base64-encoded string created from the Blob object.
   */
  toBase64() {
    return Base64.btoa(this._binaryString);
  }

  /**
   * Returns the bytes of a Blob in a new Uint8Array.
   *
   * @url https://firebase.google.com/docs/reference/js/firebase.firestore.Blob#toUint8Array
   * @returns non-null Uint8Array The Uint8Array created from the Blob object.
   */
  toUint8Array() {
    return new Uint8Array(this._binaryString.split('').map(c => c.charCodeAt(0)));
  }

  /**
   * Returns a string representation of this blob instance
   *
   * @returns {string}
   * @memberof Blob
   */
  toString() {
    return `firestore.Blob(base64: ${this.toBase64()})`;
  }
}