fix(firestore): normalize Firestore pointer path (#2929)

Author: IchordeDionysos

packages/cloud_firestore/cloud_firestore/CHANGELOG.md

@@ -19,7 +19,9 @@ Along with the below changes, the plugin has undergone a quality of life update
 
 **`CollectionReference`**:
 - **BREAKING**: Getting a collection parent document via `parent()` has been changed to a getter `parent`.
+- **BREAKING**: Getting the collection `path` now always returns the `path` without leading and trailing slashes.
 - **DEPRECATED**: Calling `document()` is deprecated in favor of `doc()`.
+- **FIX**: Equality checking of `CollectionReference` now does not depend on the original path used to create the `CollectionReference`. 
 
 **`Query`**:
 - **BREAKING**: The internal query logic has been overhauled to better assert invalid queries locally.
@@ -38,9 +40,11 @@ Along with the below changes, the plugin has undergone a quality of life update
 - **BREAKING**: `setData`/`set` has been updated to accept an instance of `SetOptions` (see below, supports `mergeFields`).
 - **BREAKING**: `get()` has been updated to accept an instance of `GetOptions` (see below).
 - **BREAKING**: Getting a document parent collection via `parent()` has been changed to a getter `parent`.
+- **BREAKING**: Getting the document `path` now always returns the `path` without leading and trailing slashes.
 - **DEPRECATED**: `documentID` has been deprecated in favor of `id`.
 - **DEPRECATED**: `setData()` has been deprecated in favor of `set()`.
 - **DEPRECATED**: `updateData()` has been deprecated in favor of `update()`.
+- **FIX**: Equality checking of `DocumentReference` now does not depend on the original path used to create the `DocumentReference`.
 
 **`DocumentChange`**:
 - **DEPRECATED**: Calling `document()` is deprecated in favor of `doc()`.

packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/internal/pointer.dart

@@ -9,13 +9,15 @@
 /// to reduce code repetition and improve testability.
 class Pointer {
   /// Create instance of [Pointer]
-  Pointer(this.path)
+  Pointer(String path)
       : assert(path != null),
         components =
             path.split('/').where((element) => element.isNotEmpty).toList();
 
-  /// The Firestore path the [Pointer] was initialized with.
-  final String path;
+  /// The Firestore normalized path of the [Pointer].
+  String get path {
+    return components.join('/');
+  }
 
   /// Pointer components of the path.
   ///

packages/cloud_firestore/cloud_firestore_platform_interface/test/internal_tests/pointer_test.dart

@@ -66,5 +66,12 @@ void main() {
       expect(Pointer('foo') == Pointer('foo'), true);
       expect(Pointer('foo') == Pointer('foo/bar'), false);
     });
+
+    test('Pointer equality with un-normalized paths', () {
+      expect(Pointer('foo') == Pointer('/foo'), true);
+      expect(Pointer('foo') == Pointer('/foo/bar'), false);
+      expect(Pointer('foo') == Pointer('foo/'), true);
+      expect(Pointer('foo') == Pointer('foo/bar/'), false);
+    });
   });
 }