feat!: use QueryDocumentSnapshot in FirestoreDataConverter

dev/src/document.ts

@@ -25,7 +25,7 @@ import {FieldPath, validateFieldPath} from './path';
 import {DocumentReference} from './reference';
 import {Serializer} from './serializer';
 import {Timestamp} from './timestamp';
-import {ApiMapValue, DocumentData, UpdateMap} from './types';
+import {ApiMapValue, defaultConverter, DocumentData, UpdateMap} from './types';
 import {isEmpty, isObject, isPlainObject} from './util';
 
 import api = google.firestore.v1;
@@ -381,11 +381,29 @@ export class DocumentSnapshot<T = DocumentData> {
       return undefined;
     }
 
-    const obj: DocumentData = {};
-    for (const prop of Object.keys(fields)) {
-      obj[prop] = this._serializer.decodeValue(fields[prop]);
+    // We only want to use the converter and create a new QueryDocumentSnapshot
+    // if a converter has been provided.
+    if (this.ref._converter !== defaultConverter) {
+      const untypedReference = new DocumentReference(
+        this.ref.firestore,
+        this.ref._path
+      );
+      return this.ref._converter.fromFirestore(
+        new QueryDocumentSnapshot<DocumentData>(
+          untypedReference,
+          this._fieldsProto!,
+          this.readTime,
+          this.createTime!,
+          this.updateTime!
+        )
+      );
+    } else {
+      const obj: DocumentData = {};
+      for (const prop of Object.keys(fields)) {
+        obj[prop] = this._serializer.decodeValue(fields[prop]);
+      }
+      return obj as T;
     }
-    return this.ref._converter.fromFirestore(obj);
   }
 
   /**

dev/src/reference.ts

@@ -558,8 +558,9 @@ export class DocumentReference<T = DocumentData> implements Serializable {
    *     return {title: post.title, author: post.author};
    *   },
    *   fromFirestore(
-   *     data: FirebaseFirestore.DocumentData
+   *     snapshot: FirebaseFirestore.QueryDocumentSnapshot
    *   ): Post {
+   *     const data = snapshot.data();
    *     return new Post(data.title, data.author);
    *   }
    * };
@@ -2167,8 +2168,9 @@ export class Query<T = DocumentData> {
    *     return {title: post.title, author: post.author};
    *   },
    *   fromFirestore(
-   *     data: FirebaseFirestore.DocumentData
+   *     snapshot: FirebaseFirestore.QueryDocumentSnapshot
    *   ): Post {
+   *     const data = snapshot.data();
    *     return new Post(data.title, data.author);
    *   }
    * };
@@ -2440,8 +2442,9 @@ export class CollectionReference<T = DocumentData> extends Query<T> {
    *     return {title: post.title, author: post.author};
    *   },
    *   fromFirestore(
-   *     data: FirebaseFirestore.DocumentData
+   *     snapshot: FirebaseFirestore.QueryDocumentSnapshot
    *   ): Post {
+   *     const data = snapshot.data();
    *     return new Post(data.title, data.author);
    *   }
    * };

dev/src/types.ts

@@ -22,6 +22,7 @@ import {FieldPath} from './path';
 import {Timestamp} from './timestamp';
 
 import api = google.firestore.v1;
+import {QueryDocumentSnapshot} from './document';
 
 /**
  * A map in the format of the Proto API
@@ -113,7 +114,7 @@ export type RBTree = any;
  *     return {title: post.title, author: post.author};
  *   },
  *   fromFirestore(
- *     data: FirebaseFirestore.DocumentData
+ *     snapshot: FirebaseFirestore.QueryDocumentSnapshot
  *   ): Post {
  *     return new Post(data.title, data.author);
  *   }
@@ -142,23 +143,19 @@ export interface FirestoreDataConverter<T> {
    * Called by the Firestore SDK to convert Firestore data into an object of
    * type T.
    */
-  fromFirestore(data: DocumentData): T;
+  fromFirestore(snapshot: QueryDocumentSnapshot): T;
 }
 
 /**
  * A default converter to use when none is provided.
  * @private
  */
 export const defaultConverter: FirestoreDataConverter<DocumentData> = {
-  toFirestore(
-    modelObject: FirebaseFirestore.DocumentData
-  ): FirebaseFirestore.DocumentData {
+  toFirestore(modelObject: DocumentData): DocumentData {
     return modelObject;
   },
-  fromFirestore(
-    data: FirebaseFirestore.DocumentData
-  ): FirebaseFirestore.DocumentData {
-    return data;
+  fromFirestore(snapshot: QueryDocumentSnapshot): DocumentData {
+    return snapshot.data()!;
   },
 };
 

dev/test/typescript.ts

@@ -58,8 +58,8 @@ xdescribe('firestore.d.ts', () => {
     toFirestore(modelObject: DocumentData): DocumentData {
       return modelObject;
     },
-    fromFirestore(data: DocumentData): DocumentData {
-      return data;
+    fromFirestore(snapshot: QueryDocumentSnapshot): DocumentData {
+      return snapshot.data();
     },
   };
 

dev/test/util/helpers.ts

@@ -19,7 +19,11 @@ import {Duplex} from 'stream';
 import * as through2 from 'through2';
 
 import * as proto from '../../protos/firestore_v1_proto_api';
-import {Firestore} from '../../src';
+import {
+  Firestore,
+  FirestoreDataConverter,
+  QueryDocumentSnapshot,
+} from '../../src';
 import {ClientPool} from '../../src/pool';
 import {DocumentData, GapicClient} from '../../src/types';
 
@@ -348,7 +352,8 @@ export const postConverter = {
   toFirestore(post: Post): DocumentData {
     return {title: post.title, author: post.author};
   },
-  fromFirestore(data: DocumentData): Post {
+  fromFirestore(snapshot: QueryDocumentSnapshot): Post {
+    const data = snapshot.data();
     return new Post(data.title, data.author);
   },
 };

types/firestore.d.ts

@@ -63,8 +63,9 @@ declare namespace FirebaseFirestore {
    *     return {title: post.title, author: post.author};
    *   },
    *   fromFirestore(
-   *     data: FirebaseFirestore.DocumentData
+   *     snapshot: FirebaseFirestore.QueryDocumentSnapshot
    *   ): Post {
+   *     const data = snapshot.data();
    *     return new Post(data.title, data.author);
    *   }
    * };
@@ -92,7 +93,7 @@ declare namespace FirebaseFirestore {
      * Called by the Firestore SDK to convert Firestore data into an object of
      * type T.
      */
-    fromFirestore(data: DocumentData): T;
+    fromFirestore(snapshot: QueryDocumentSnapshot): T;
   }
 
   /**