feat: use firestore db and admin singletons stored as private fields …

…in a class, #28

examples/example-parser.js

@@ -8,7 +8,7 @@ const main = async () => {
   const handler = new CsvToFireStore(path.resolve(__dirname, 'example.csv'))
 
    // Directly override CsvToFireStore's ParserCSV read() method
-   // and csv_rows[] {Object[]} array to include only the "name" column 
+   // and csv_rows[] {Object[]} array to include only the "name" column
    // during Firestore upload
   handler.read = (row) => {
     handler.csv_rows.push({

index.js

@@ -2,9 +2,11 @@ require('dotenv').config()
 const ParserCSV = require('./src/lib/classes/parser')
 const FirestoreData = require('./src/lib/classes/firestore-data/firestore-data')
 const CsvToFireStore = require('./src/lib/classes/csvtofirestore')
+const FirebaseDB = require('./src/lib/classes/firebasedb')
 
 module.exports = {
   CsvToFireStore,
   ParserCSV,
-  FirestoreData
+  FirestoreData,
+  FirebaseDB
 }

src/lib/classes/csvtofirestore/index.js

@@ -1,23 +1,37 @@
 const ParserCSV = require('../parser')
-const { uploadToCollection } = require('../firestore-data')
+const FirestoreData = require('../firestore-data/firestore-data')
 
 /**
- * Read the contents of a CSV file and
- * upload the CSV contents to a Firestore collection.
+ * Class that reads the contents of a CSV file and
+ * uploads the CSV contents to a Firestore collection.
  */
 class CsvToFireStore extends ParserCSV {
   /**
-   * Upload the internal CSV file contents to a Firestore collection.
-   * The Firestore collection will be created if it does not yet exist.
+   * `FirestoreData` class instance containing methods for managing Firestore data.
+   * It also contains internal Firebase `admin` and `firestore` Singletons.
+   * @type {object}
+   */
+  #firestore
+
+  constructor (csvFilePath) {
+    super(csvFilePath)
+    this.#firestore = new FirestoreData()
+  }
+
+  /**
+   * Uploads the internal CSV file contents, or external data that resembles `ParserCSV`'s
+   * JSON Object[] array structure to a Firestore collection, creating the Firestore
+   * collection if it does not yet exist.
    * @param {String} collectionName - Firestore collection name
-   * @param {Boolean} overwrite - delete all documents in the collection before uploading data
+   * @param {Boolean} overwrite - Flag to delete all documents in the collection before uploading data
    * @param {Object[]} data - Array of objects (1 level only) to upload
    */
   async firestoreUpload (collectionName, overwrite = true, data = []) {
     const dataToUpload = (data && data.length > 0)
       ? data
       : this.data()
-    await uploadToCollection(collectionName, dataToUpload, overwrite)
+
+    await this.#firestore.uploadToCollection(collectionName, dataToUpload, overwrite)
   }
 }
 

src/lib/classes/firebasedb/index.js

@@ -0,0 +1,160 @@
+require('dotenv').config()
+const { initializeApp, getApps, getApp } = require('firebase-admin/app')
+const { getFirestore } = require('firebase-admin/firestore')
+const admin = require('firebase-admin')
+
+/**
+ * @class FirebaseDB
+ * @description Class that provides a Singleton instance of the Firebase `admin` and `firestore` database objects
+ * initialized using the service account credentials in the `.env` file. It also displays relevant firebase-admin
+ * and Firestore database information.
+ */
+class FirebaseDB {
+  /**
+   * csv-firestore internal Firebase admin namespace
+   * @type {object}
+   */
+  #admin
+
+  /**
+   * Firestore database object namespace, containing methods for
+   * interfacing with the Firestore database.
+   * @type {object}
+   */
+  #db
+
+  /**
+   * Initialized Fireabase app name
+   * @type {string}
+   */
+  #appName
+
+  /**
+   * Minimal Firestore database details (also available in `#db`)
+   * @type {object}
+   */
+  #dbSettings = {
+    /**
+     * Firestore database ID (name)
+     * @type {string}
+     */
+    databaseId: null,
+    /**
+     * Firestore project ID
+     * @type {string}
+     */
+    projectId: null
+  }
+
+  /**
+   * Version of the firebase-admin package that created the `#admin` and firestore `#db` Singletons
+   * @type {string}
+   */
+  #sdkVersion
+
+  /**
+   * Creates an instance of the `FirebaseDB` class and intializes or uses and existing
+   * Firebase `admin` and `firestore` database Singleton using the firebase-admin
+   * `getApp()` and `getApps()` functions.
+   * @constructor
+   */
+  constructor () {
+    this.initialize()
+  }
+
+  /**
+   * Initializes the Firebase `admin` and Firestore `database` using the Firebase credentials in the `.env` file.
+   * Ensures Singleton Firebase app instances by checking initialized Firebase apps using the `getApps()` and `getApp()`
+   * firebase-admin functions.
+   * @param {string} [appName] (Optional) Firebase app name to tag a Firebase app instance.
+   * @returns {void}
+   */
+  initialize () {
+    const appsLength = getApps().length
+
+    if (!appsLength) {
+      if (process.env.FIREBASE_SERVICE_ACC === undefined || process.env.FIREBASE_PRIVATE_KEY === undefined) {
+        console.log('FIREBASE_SERVICE_ACC or FIREBASE_PRIVATE_KEY is missing.')
+        process.exit(1)
+      }
+
+      // Add double-quotes around the "private_key" JSON
+      const serviceAccount = JSON.parse(process.env.FIREBASE_SERVICE_ACC)
+      serviceAccount.private_key = process.env.FIREBASE_PRIVATE_KEY.replace(/\\n/g, '\n')
+
+      // Initialize a "[DEFAULT]" Firebase app
+      // Developers expect only one (1) app instance per firebase-admin version
+      initializeApp({
+        credential: admin.credential.cert(serviceAccount)
+      })
+    }
+
+    // Use existing app instance
+    const app = getApp()
+
+    this.#db = getFirestore(app)
+    this.#admin = admin
+    this.#appName = app.name
+    this.#sdkVersion = admin.SDK_VERSION
+
+    this.#dbSettings = {
+      databaseId: this.#db.databaseId,
+      projectId: this.#db.projectId
+    }
+  }
+
+  /**
+   * Prints relevant firebase-admin (firestore, app) information to screen.
+   * @returns {void}
+   */
+  log () {
+    let log = `Firebase app name: ${this.#appName}\n`
+    log += `Firestore database ID: ${this.#dbSettings.databaseId}\n`
+    log += `Firestore project ID: ${this.#dbSettings.projectId}\n`
+    log += `SDK Version: ${this.sdkVersion}`
+
+    console.log(log)
+  }
+
+  /**
+   * Firestore admin getter
+   * @returns {object} Inialized Firebase admin object namespace
+   */
+  get admin () {
+    return this.#admin
+  }
+
+  /**
+   * Firestore database getter
+   * @returns {object} Inialized Firestore database object
+   */
+  get db () {
+    return this.#db
+  }
+
+  /**
+   * Firebase app name getter
+   * @returns {string} Initialized Firebase app name
+   */
+  get appName () {
+    return this.#appName
+  }
+
+  /**
+   * firebase-admin SDK version getter
+   * @returns {string} firebase-admin SDK version
+   */
+  get sdkVersion () {
+    return this.#sdkVersion
+  }
+
+  /**
+   * Firestore database settings getter
+   * @returns {object} Minimal Firestore database settings object
+   */
+  get dbSettings () {
+    return this.#dbSettings
+  }
+}
+
+module.exports = FirebaseDB

src/lib/classes/firestore-data/firestore-data.js

@@ -1,32 +1,19 @@
-const { db, admin } = require('./db')
+const FirebaseDB = require('../firebasedb')
 
 /**
  * A wrapper around firebase-admin for bulk delete and write data operations to specified Firestore collections.
- * Uses firebase-admin v10.0.2.
- * Requires a privileged environment to run while using the project's
- *    service account JSON credentials (see db.js)
+ * Initializes and keeps a `firestore` and `admin` Singleton reference from firebase-admin for data access.
+ * Uses firebase-admin v13.1.0.
+ * Requires a privileged environment to run using the project's
+ *    service account JSON credentials (see .env file)
  */
-class FirestoreData {
-  /** Firestore DB */
-  #db
-
-  /** Firebase admin */
-  #admin
-
-  /**
-   * Initialize FirestoreData with Firestore DB and Firebase admin
-   */
-  constructor () {
-    this.#db = db
-    this.#admin = admin
-  }
-
+class FirestoreData extends FirebaseDB {
   /**
    * Delete a firestore collection including all its documents
    * @param {String} collectionName - firestore collection name
    */
   async deleteCollection (collectionName) {
-    const collectionRef = db.collection(collectionName)
+    const collectionRef = this.db.collection(collectionName)
     const query = collectionRef.offset(0)
     // const query = collectionRef.orderBy(fieldName)
 
@@ -51,7 +38,7 @@ class FirestoreData {
     }
 
     // Delete documents in a batch
-    const batch = db.batch()
+    const batch = this.db.batch()
     snapshot.docs.forEach((doc) => {
       batch.delete(doc.ref)
     })
@@ -72,14 +59,14 @@ class FirestoreData {
    * @param {Boolean} overwrite - delete all documents in the collection before uploading data
    */
   async uploadToCollection (collectionName, data, overwrite = true) {
-    const batch = db.batch()
+    const batch = this.db.batch()
 
     if (overwrite) {
       await this.deleteCollection(collectionName)
     }
 
     data.forEach((item, index) => {
-      const docRef = db.collection(collectionName).doc()
+      const docRef = this.db.collection(collectionName).doc()
       batch.set(docRef, item)
     })
 
@@ -93,7 +80,7 @@ class FirestoreData {
    * @returns {Boolean} true|false
    */
   async fieldNameExists (collectionName, fieldName) {
-    const collectionRef = db.collection(collectionName)
+    const collectionRef = this.db.collection(collectionName)
     const query = collectionRef.orderBy(fieldName).limit(1)
 
     try {
@@ -103,20 +90,6 @@ class FirestoreData {
       throw new Error(err.message)
     }
   }
-
-  /**
-   * Return the private Firestore DB
-   */
-  get db () {
-    return this.#db
-  }
-
-  /**
-   * Return the private Firbase admin
-   */
-  get admin () {
-    return this.#admin
-  }
 }
 
 module.exports = FirestoreData

src/lib/classes/firestore-data/db.js → src/lib/utils/db.js

@@ -3,6 +3,7 @@ const { initializeApp, getApps, getApp } = require('firebase-admin/app')
 const { getFirestore } = require('firebase-admin/firestore')
 const admin = require('firebase-admin')
 
+// Modular Singleton Firebase app initialization
 if (!getApps().length) {
   if (process.env.FIREBASE_SERVICE_ACC === undefined || process.env.FIREBASE_PRIVATE_KEY === undefined) {
     console.log('FIREBASE_SERVICE_ACC or FIREBASE_PRIVATE_KEY is missing.')
@@ -13,10 +14,9 @@ if (!getApps().length) {
   const serviceAccount = JSON.parse(process.env.FIREBASE_SERVICE_ACC)
   serviceAccount.private_key = process.env.FIREBASE_PRIVATE_KEY.replace(/\\n/g, '\n')
 
-  initializeApp(
-    { credential: admin.credential.cert(serviceAccount) },
-    'csv-firestore-app'
-  )
+  initializeApp({
+    credential: admin.credential.cert(serviceAccount)
+  })
 }
 
 // Use existing app instance