test(spanner): add queue acceptance tests

acceptance/data/fixtures.rb

@@ -196,6 +196,17 @@ def items_ddl_statement
       ITEMS
     end
 
+    # Not part of schema_ddl_statements: queues need an Enterprise edition
+    # instance, and the emulator doesn't support them yet.
+    def queue_ddl_statement
+      <<~QUEUE
+        CREATE QUEUE IF NOT EXISTS TestQueue (
+        Id INT64 NOT NULL,
+        Payload BYTES(MAX) NOT NULL
+        ) PRIMARY KEY (Id)
+      QUEUE
+    end
+
     def schema_pg_ddl_statements
       [
         stuff_pg_ddl_statement,

google-cloud-spanner/acceptance/spanner/client/queues_test.rb

@@ -0,0 +1,59 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+require "spanner_helper"
+
+# An ack without ignore_not_found fails with NOT_FOUND unless the message
+# exists, so a successful ack also shows that the send landed.
+describe "Spanner Client Queues", :queues, :spanner do
+  let(:db) { spanner_client }
+
+  before do
+    skip "Cloud Spanner Emulator does not yet support Queues (Send & Ack)" if emulator_enabled?
+
+    # Created once per run, in the per-run test database.
+    $spanner_test_queue_created ||= begin
+      db_job = db.database.update statements: [queue_ddl_statement]
+      db_job.wait_until_done!
+      raise GRPC::BadStatus.new(db_job.error.code, db_job.error.message) if db_job.error?
+      true
+    end
+  end
+
+  it "sends and acks messages with Client#commit" do
+    commit_time = db.commit do |c|
+      c.send_message "TestQueue", 1, StringIO.new("payload1")
+      c.send_message "TestQueue", 2, StringIO.new("payload2")
+    end
+    _(commit_time).must_be_kind_of Time
+
+    commit_time = db.commit do |c|
+      c.ack_message "TestQueue", 1
+      c.ack_message "TestQueue", 2
+    end
+    _(commit_time).must_be_kind_of Time
+  end
+
+  it "sends and acks a message with Client#transaction" do
+    commit_time = db.transaction do |tx|
+      tx.send_message "TestQueue", 3, StringIO.new("payload3")
+    end
+    _(commit_time).must_be_kind_of Time
+
+    commit_time = db.transaction do |tx|
+      tx.ack_message "TestQueue", 3
+    end
+    _(commit_time).must_be_kind_of Time
+  end
+end