Add Firestore source tests (#410)

Author: ehsannas

firestore/integration_test_internal/CMakeLists.txt

@@ -92,6 +92,7 @@ set(FIREBASE_INTEGRATION_TEST_PORTABLE_TEST_SRCS
     src/sanity_test.cc
     src/server_timestamp_test.cc
     src/smoke_test.cc
+    src/source_test.cc
     src/transaction_test.cc
     src/type_test.cc
     src/validation_test.cc

firestore/integration_test_internal/src/firestore_integration_test.cc

@@ -195,6 +195,13 @@ DocumentReference FirestoreIntegrationTest::Document() const {
   return TestFirestore()->Document(DocumentPath());
 }
 
+DocumentReference FirestoreIntegrationTest::DocumentWithData(
+    const MapFieldValue& data) const {
+  DocumentReference docRef = Document();
+  WriteDocument(docRef, data);
+  return docRef;
+}
+
 void FirestoreIntegrationTest::WriteDocument(DocumentReference reference,
                                              const MapFieldValue& data) const {
   Future<void> future = reference.Set(data);
@@ -257,6 +264,16 @@ std::vector<MapFieldValue> FirestoreIntegrationTest::QuerySnapshotToValues(
   return result;
 }
 
+std::map<std::string, MapFieldValue>
+FirestoreIntegrationTest::QuerySnapshotToMap(
+    const QuerySnapshot& snapshot) const {
+  std::map<std::string, MapFieldValue> result;
+  for (const DocumentSnapshot& doc : snapshot.documents()) {
+    result[doc.id()] = doc.GetData();
+  }
+  return result;
+}
+
 /* static */
 void FirestoreIntegrationTest::Await(const Future<void>& future) {
   while (future.status() == FutureStatus::kFutureStatusPending) {

firestore/integration_test_internal/src/firestore_integration_test.h

@@ -228,6 +228,10 @@ class FirestoreIntegrationTest : public testing::Test {
   // Return a reference to the document with auto-generated id.
   DocumentReference Document() const;
 
+  // Returns a reference to a document with auto-generated id. Writes the given
+  // data to the document and waits for the write to complete.
+  DocumentReference DocumentWithData(const MapFieldValue& data) const;
+
   // Write to the specified document and wait for the write to complete.
   void WriteDocument(DocumentReference reference,
                      const MapFieldValue& data) const;
@@ -262,6 +266,10 @@ class FirestoreIntegrationTest : public testing::Test {
   std::vector<MapFieldValue> QuerySnapshotToValues(
       const QuerySnapshot& snapshot) const;
 
+  // Convert a QuerySnapshot to a map from document id to document content.
+  std::map<std::string, MapFieldValue> QuerySnapshotToMap(
+      const QuerySnapshot& snapshot) const;
+
   // TODO(zxu): add a helper function to block on signal.
 
   // A helper function to block until the future completes.