fix(samples): close firestore instance in test

samples/snippets/src/main/java/com/example/firestore/Quickstart.java

@@ -205,5 +205,11 @@ public static void main(String[] args) throws Exception {
     String projectId = (args.length == 0) ? null : args[0];
     Quickstart quickStart = (projectId != null) ? new Quickstart(projectId) : new Quickstart();
     quickStart.run();
+    quickStart.close();
+  }
+
+  /** Closes the gRPC channels associated with this instance and frees up their resources. */
+  void close() throws Exception {
+    db.close();
   }
 }

samples/snippets/src/main/java/com/example/firestore/snippets/ListenDataSnippets.java

@@ -222,4 +222,8 @@ public void onEvent(@Nullable QuerySnapshot snapshots,
     // [END listen_errors]
   }
 
+  /** Closes the gRPC channels associated with this instance and frees up their resources. */
+  void close() throws Exception {
+    db.close();
+  }
 }

samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java

@@ -469,4 +469,8 @@ public void updateDocumentIncrement() throws ExecutionException, InterruptedExce
     updateFuture.get();
   }
 
+  /** Closes the gRPC channels associated with this instance and frees up their resources. */
+  void close() throws Exception {
+    db.close();
+  }
 }

samples/snippets/src/main/java/com/example/firestore/snippets/QueryDataSnippets.java

@@ -644,4 +644,9 @@ Query filterNotIn() {
     // [END fs_filter_not_in]
     return query;
   }
+
+  /** Closes the gRPC channels associated with this instance and frees up their resources. */
+  void close() throws Exception {
+    db.close();
+  }
 }

samples/snippets/src/main/java/com/example/firestore/snippets/RetrieveDataSnippets.java

@@ -171,4 +171,9 @@ public Iterable<CollectionReference> listCollections() throws Exception {
     // [END fs_get_collections]
     return collections;
   }
+
+  /** Closes the gRPC channels associated with this instance and frees up their resources. */
+  void close() throws Exception {
+    db.close();
+  }
 }

samples/snippets/src/test/java/com/example/firestore/BaseIntegrationTest.java

@@ -28,6 +28,7 @@
 import com.google.cloud.firestore.FirestoreOptions;
 import com.google.cloud.firestore.QuerySnapshot;
 import java.util.Map;
+import org.junit.AfterClass;
 import org.junit.BeforeClass;
 
 /**
@@ -83,4 +84,8 @@ protected  static void deleteAllDocuments(Firestore db) throws Exception {
     }
   }
 
+  @AfterClass
+  public static void tearDownAfterClass() throws Exception {
+    db.close();
+  }
 }

samples/snippets/src/test/java/com/example/firestore/QuickstartIT.java

@@ -113,5 +113,6 @@ private void deleteAllDocuments() throws Exception {
   @After
   public void tearDown() throws Exception {
     deleteAllDocuments();
+    quickstart.close();
   }
 }

samples/snippets/src/test/java/com/example/firestore/snippets/ListenDataSnippetsIT.java

@@ -75,5 +75,6 @@ public void testListenForChanges() throws Exception {
   @AfterClass
   public static void tearDown() throws Exception {
     deleteAllDocuments(db);
+    listenDataSnippets.close();
   }
 }

samples/snippets/src/test/java/com/example/firestore/snippets/ManageDataSnippetsIT.java

@@ -202,5 +202,6 @@ public void testUpdateDocumentIncrementSuccessful() throws Exception {
   public static void tearDown() throws Exception {
     manageDataSnippets.deleteCollection(db.collection("cities"), 10);
     manageDataSnippets.deleteCollection(db.collection("users"), 10);
+    manageDataSnippets.close();
   }
 }

samples/snippets/src/test/java/com/example/firestore/snippets/QueryDataSnippetsIT.java

@@ -284,5 +284,6 @@ private List<String> getResults(Query query) throws Exception {
   @AfterClass
   public static void tearDown() throws Exception {
     deleteAllDocuments(db);
+    queryDataSnippets.close();
   }
 }

samples/snippets/src/test/java/com/example/firestore/snippets/RetrieveDataSnippetsIT.java

@@ -126,5 +126,6 @@ private static void deleteAllDocuments() throws Exception {
   @AfterClass
   public static void tearDownAfterClass() throws Exception {
     deleteAllDocuments();
+    retrieveDataSnippets.close();
   }
 }