cosmosdb-adapter/cosmos-adapter.js

A Node.js adapter for Cosmos DB with functions commonly (re)implemented in Azure projects.

const { CosmosClient, ItemResponse, FeedResponse, PermissionMode } = require('@azure/cosmos');

class CosmosDbAdapter {
  /**
   * @param {string} endpoint 
   * @param {string} key 
   * @param {{ enableEndpointDiscovery: Boolean }} options
   */
  constructor(endpoint, key, options = { enableEndpointDiscorery: true }) {
    this.client = new CosmosClient({
      endpoint, 
      key, 
      connectionPolicy: { 
        enableEndpointDiscovery: options.enableEndpointDiscovery 
      } 
    });
  }

  /**
   * @param {string} databaseId 
   * @param {string} containerId 
   * @param {string} id 
   * @param {string} partitionValue 
   * @param {object} document 
   * @returns {Promise<ItemResponse<object>>}
   */
  async read(databaseId, containerId, id, partitionValue) {
    return await this.client
        .database(databaseId)
        .container(containerId)
        .item(id, partitionValue)
        .read();
  }

  /**
   * @param {string} databaseId 
   * @param {string} containerId 
   * @param {object} document 
   * @returns {Promise<ItemResponse<object>>}
   */
  async write(databaseId, containerId, document) {
    return await this.client
        .database(databaseId)
        .container(containerId)
        .items.create(document);
  }

  /**
   * @param {string} databaseId 
   * @param {string} containerId 
   * @param {string} id 
   * @param {string} partitionValue 
   * @param {object} document 
   * @returns {Promise<ItemResponse<object>>}
   */
  async replace(databaseId, containerId, id, partitionValue, document) {
    return await this.client
        .database(databaseId)
        .container(containerId)
        .item(id, partitionValue)
        .replace(document);
  }

  /**
   * @param {string} databaseId 
   * @param {string} containerId 
   * @param {string} id 
   * @param {string} partitionValue 
   * @param {object} document 
   * @returns {Promise<ItemResponse<object>>}
   */
  async delete(databaseId, containerId, id, partitionValue) {
    return await this.client
        .database(databaseId)
        .container(containerId)
        .item(id, partitionValue)
        .delete();
  }

  /**
   * @param {string} databaseId 
   * @param {string} containerId 
   * @param {string} idProperty 
   * @param {string} idValue 
   * @param {string} partitionProperty 
   * @param {string} partitionValue 
   * @returns {Promise<FeedResponse<any>>}
   */
  async get(databaseId, containerId, idProperty, idValue, partitionProperty, partitionValue) {
    let query = `SELECT * FROM ${containerId} as c WHERE c.${idProperty} = '${idValue}' and c.${partitionProperty} = '${partitionValue}'`;
    return await this.execute(databaseId, containerId, query);
  }

  /**
   * @param {string} databaseId 
   * @param {string} containerId 
   * @param {string} query 
   * @returns {Promise<FeedResponse<any>>}
   */
  async execute(databaseId, containerId, query) {
    const querySpec = {
        query: query,
        parameters: []
    };
    return await this.client
        .database(databaseId)
        .container(containerId)
        .items.query(querySpec)
        .fetchAll();
  }

  /**
   * @param {string} databaseId 
   * @param {string} containerId 
   * @param {string} itemId 
   * @param {string} partitionKey 
   * @param {string} userId 
   * @returns {Promise<object>}
   */
  async getItemReadToken(databaseId, containerId, itemId, partitionKey, userId) {
    const database = await this.client.database(databaseId);
    const container = await database.container(containerId);
    const item = await container.item(itemId, partitionKey);

    let user;
    try {
        const userResponse = await database.users.create({ id: userId });
        user = userResponse.user;
    } catch(err) {
        user = await database.user(userId);
    }

    const permissionDef = { id: `${databaseId}.${containerId}.${partitionKey}.${itemId}.read`, permissionMode: PermissionMode.Read, resource: item.url };
    let permission;
    try {
        const permissionResponse = await user.permissions.create(permissionDef, { resourceTokenExpirySeconds: 3600 });
        permission = permissionResponse.permission;
    } catch(err) {
        permission = await user.permission(permissionDef.id);
    }

    const { resource: permDef } = await permission.read();
    return { [item.url]: permDef._token };
  }
}

module.exports.CosmosDbAdapter = CosmosDbAdapter;