Snapshot listener source from cache (#12370)

Author: milaGGL

Firestore/CHANGELOG.md

@@ -1,3 +1,6 @@
+# Unreleased
+- [feature] Enable snapshot listener option to retrieve data from local cache only. (#12370)
+
 # 10.22.0
 - [fixed] Fix the flaky offline behaviour when using `arrayRemove` on `Map` object. (#12378)
 

Firestore/Example/Firestore.xcodeproj/project.pbxproj

@@ -41,6 +41,7 @@
 #include "Firestore/core/src/bundle/bundle_reader.h"
 #include "Firestore/core/src/bundle/bundle_serializer.h"
 #include "Firestore/core/src/core/field_filter.h"
+#import "Firestore/core/src/core/listen_options.h"
 #include "Firestore/core/src/credentials/user.h"
 #include "Firestore/core/src/local/persistence.h"
 #include "Firestore/core/src/local/target_data.h"
@@ -79,10 +80,12 @@
 using firebase::firestore::Error;
 using firebase::firestore::google_firestore_v1_ArrayValue;
 using firebase::firestore::google_firestore_v1_Value;
+using firebase::firestore::api::ListenSource;
 using firebase::firestore::api::LoadBundleTask;
 using firebase::firestore::bundle::BundleReader;
 using firebase::firestore::bundle::BundleSerializer;
 using firebase::firestore::core::DocumentViewChange;
+using firebase::firestore::core::ListenOptions;
 using firebase::firestore::core::Query;
 using firebase::firestore::credentials::User;
 using firebase::firestore::local::Persistence;
@@ -385,11 +388,25 @@ - (DocumentViewChange)parseChange:(NSDictionary *)jsonDoc ofType:(DocumentViewCh
   return DocumentViewChange{std::move(doc), type};
 }
 
+- (ListenOptions)parseOptions:(NSDictionary *)optionsSpec {
+  ListenOptions options = ListenOptions::FromIncludeMetadataChanges(true);
+
+  if (optionsSpec != nil) {
+    ListenSource source =
+        [optionsSpec[@"source"] isEqual:@"cache"] ? ListenSource::Cache : ListenSource::Default;
+    // include_metadata_changes are default to true in spec tests
+    options = ListenOptions::FromOptions(true, source);
+  }
+
+  return options;
+}
+
 #pragma mark - Methods for doing the steps of the spec test.
 
 - (void)doListen:(NSDictionary *)listenSpec {
   Query query = [self parseQuery:listenSpec[@"query"]];
-  TargetId actualID = [self.driver addUserListenerWithQuery:std::move(query)];
+  ListenOptions options = [self parseOptions:listenSpec[@"options"]];
+  TargetId actualID = [self.driver addUserListenerWithQuery:std::move(query) options:options];
 
   TargetId expectedID = [listenSpec[@"targetId"] intValue];
   XCTAssertEqual(actualID, expectedID, @"targetID assigned to listen");

Firestore/Example/Tests/SpecTests/FSTSpecTests.mm

@@ -146,9 +146,10 @@ typedef std::
  * Resulting events are captured and made available via the capturedEventsSinceLastCall method.
  *
  * @param query A valid query to execute against the backend.
+ * @param options A listen option to configure snapshot listener.
  * @return The target ID assigned by the system to track the query.
  */
-- (model::TargetId)addUserListenerWithQuery:(core::Query)query;
+- (model::TargetId)addUserListenerWithQuery:(core::Query)query options:(core::ListenOptions)options;
 
 /**
  * Removes a listener from the FSTSyncEngine as if the user had removed a listener corresponding

Firestore/Example/Tests/SpecTests/FSTSyncEngineTestDriver.h

@@ -476,10 +476,8 @@ - (FSTOutstandingWrite *)receiveWriteError:(int)errorCode
   return result;
 }
 
-- (TargetId)addUserListenerWithQuery:(Query)query {
-  // TODO(dimond): Allow customizing listen options in spec tests
+- (TargetId)addUserListenerWithQuery:(Query)query options:(ListenOptions)options {
   // TODO(dimond): Change spec tests to verify isFromCache on snapshots
-  ListenOptions options = ListenOptions::FromIncludeMetadataChanges(true);
   auto listener = QueryListener::Create(
       query, options, [self, query](const StatusOr<ViewSnapshot> &maybe_snapshot) {
         FSTQueryEvent *event = [[FSTQueryEvent alloc] init];