add filtered query test

Author: milaGGL

google-cloud-firestore/src/main/java/com/google/cloud/firestore/BasePath.java

@@ -116,9 +116,9 @@ boolean isPrefixOf(BasePath<B> path) {
   /**
    * Compare the current path against another Path object.
    *
-   * <p>The comparison is done segment by segment, with the following rules: 1. Numeric IDs
-   * (starting with "__id" and ending with "__") are compared numerically. 2. String segments are
-   * compared lexicographically. 3. Numeric IDs are considered smaller than string segments.
+   * <p>Compare the current path against another Path object. Paths are compared segment by segment,
+   * prioritizing numeric IDs (e.g., "__id123__") in ascending order, followed by string segments in
+   * lexicographical order.
    *
    * @param other The path to compare to.
    * @return -1 if current is less than other, 1 if current greater than other, 0 if equal
@@ -141,26 +141,26 @@ public int compareTo(@Nonnull B other) {
   private int compareSegments(String segment1, String segment2) {
     // 1. Check if one segment is numeric and the other is not
     if (isNumericId(segment1) && !isNumericId(segment2)) {
-      return -1; // Numeric comes first
+      return -1;
     } else if (!isNumericId(segment1) && isNumericId(segment2)) {
-      return 1; // String comes later
+      return 1;
     }
 
     // 2. If both are numeric, compare numerically
     if (isNumericId(segment1) && isNumericId(segment2)) {
-      long id1 = extractNumericId(segment1);
-      long id2 = extractNumericId(segment2);
-      return Long.compare(id1, id2);
+      return Long.compare(extractNumericId(segment1), extractNumericId(segment2));
     }
 
     // 3. If both are strings, compare lexicographically
     return segment1.compareTo(segment2);
   }
 
+  // Checks if a segment is a numeric ID (starts with "__id" and ends with "__").
   private boolean isNumericId(String segment) {
     return segment.startsWith("__id") && segment.endsWith("__");
   }
 
+  //  Extracts the numeric value from a numeric ID segment.
   private long extractNumericId(String segment) {
     return Long.parseLong(segment.substring(4, segment.length() - 2));
   }

google-cloud-firestore/src/test/java/com/google/cloud/firestore/it/ITQueryWatchTest.java

@@ -31,6 +31,7 @@
 import com.google.cloud.firestore.DocumentReference;
 import com.google.cloud.firestore.DocumentSnapshot;
 import com.google.cloud.firestore.EventListener;
+import com.google.cloud.firestore.FieldPath;
 import com.google.cloud.firestore.FieldValue;
 import com.google.cloud.firestore.FirestoreException;
 import com.google.cloud.firestore.ListenerRegistration;
@@ -647,7 +648,7 @@ public void shutdownNowPreventsAddingNewListener() throws Exception {
   }
 
   @Test
-  public void snapshotListenerSortsDocumentsByDocumentIdInTheSameOrderAsServer() throws Exception {
+  public void snapshotListenerSortsQueryByDocumentIdInTheSameOrderAsServer() throws Exception {
     CollectionReference col = randomColl;
 
     firestore
@@ -690,6 +691,54 @@ public void snapshotListenerSortsDocumentsByDocumentIdInTheSameOrderAsServer() t
     assertEquals(expectedOrder, listenerOrder); // Assert order in the SDK
   }
 
+  @Test
+  public void snapshotListenerSortsFilteredQueryByDocumentIdInTheSameOrderAsServer()
+      throws Exception {
+    CollectionReference col = randomColl;
+
+    firestore
+        .batch()
+        .set(col.document("A"), Collections.singletonMap("a", 1))
+        .set(col.document("a"), Collections.singletonMap("a", 1))
+        .set(col.document("Aa"), Collections.singletonMap("a", 1))
+        .set(col.document("7"), Collections.singletonMap("a", 1))
+        .set(col.document("12"), Collections.singletonMap("a", 1))
+        .set(col.document("__id7__"), Collections.singletonMap("a", 1))
+        .set(col.document("__id12__"), Collections.singletonMap("a", 1))
+        .commit()
+        .get();
+
+    Query query =
+        col.whereGreaterThan(FieldPath.documentId(), "__id7__")
+            .whereLessThanOrEqualTo(FieldPath.documentId(), "A")
+            .orderBy("__name__", Direction.ASCENDING);
+    List<String> expectedOrder = Arrays.asList("__id12__", "12", "7", "A");
+
+    QuerySnapshot snapshot = query.get().get();
+    List<String> queryOrder =
+        snapshot.getDocuments().stream().map(doc -> doc.getId()).collect(Collectors.toList());
+    assertEquals(expectedOrder, queryOrder); // Assert order from backend
+
+    CountDownLatch latch = new CountDownLatch(1);
+    List<String> listenerOrder = new ArrayList<>();
+
+    ListenerRegistration registration =
+        query.addSnapshotListener(
+            (value, error) -> {
+              listenerOrder.addAll(
+                  value.getDocuments().stream()
+                      .map(doc -> doc.getId())
+                      .collect(Collectors.toList()));
+
+              latch.countDown();
+            });
+
+    latch.await();
+    registration.remove();
+
+    assertEquals(expectedOrder, listenerOrder); // Assert order in the SDK
+  }
+
   /**
    * A tuple class used by {@code #queryWatch}. This class represents an event delivered to the
    * registered query listener.