test(pubsub): add simple integration test

Author: suzmue

Cargo.lock

@@ -60,6 +60,10 @@ path    = "../../src/generated/cloud/bigquery/v2"
 package = "google-cloud-firestore"
 path    = "../../src/firestore"
 
+[dependencies.pubsub]
+package = "google-cloud-pubsub"
+path    = "../../src/pubsub"
+
 [dependencies.showcase]
 package = "google-cloud-showcase-v1beta1"
 path    = "../../src/generated/showcase"

src/integration-tests/Cargo.toml

@@ -19,6 +19,7 @@ pub type Result<T> = anyhow::Result<T>;
 pub mod bigquery;
 pub mod error_details;
 pub mod firestore;
+pub mod pubsub;
 pub mod secret_manager;
 pub mod showcase;
 pub mod sql;

src/integration-tests/src/lib.rs

@@ -0,0 +1,90 @@
+// Copyright 2025 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.
+
+use pubsub::{client::TopicAdmin, model::Topic};
+use rand::{Rng, distr::Alphanumeric};
+
+use crate::Result;
+
+pub async fn basic_topic(builder: pubsub::builder::topic_admin::ClientBuilder) -> Result<()> {
+    // Enable a basic subscriber. Useful to troubleshoot problems and visually
+    // verify tracing is doing something.
+    #[cfg(feature = "log-integration-tests")]
+    let _guard = {
+        use tracing_subscriber::fmt::format::FmtSpan;
+        let subscriber = tracing_subscriber::fmt()
+            .with_level(true)
+            .with_thread_ids(true)
+            .with_span_events(FmtSpan::NEW | FmtSpan::CLOSE)
+            .finish();
+
+        tracing::subscriber::set_default(subscriber)
+    };
+
+    let project = crate::project_id()?;
+    let client = builder.build().await?;
+    let (topic_admin, topic) = create_test_topic().await?;
+
+    tracing::info!("testing list_topics()");
+    let topics = client
+        .list_topics()
+        .set_project(format!("projects/{project}"))
+        .send()
+        .await?;
+    tracing::info!("success with list_topics={topics:?}");
+    assert!(topics.topics.iter().any(|x| x.name == topic.name.clone()));
+
+    cleanup_test_topic(topic_admin, topic.name.clone()).await?;
+
+    Ok(())
+}
+
+pub const TOPIC_ID_LENGTH: usize = 255;
+
+fn random_topic_id(project: String) -> String {
+    let prefix = "topic-";
+    let topic_id: String = rand::rng()
+        .sample_iter(&Alphanumeric)
+        .take(TOPIC_ID_LENGTH - prefix.len())
+        .map(char::from)
+        .collect();
+    format!("projects/{project}/topics/{prefix}{topic_id}")
+}
+
+pub async fn create_test_topic() -> Result<(TopicAdmin, Topic)> {
+    let project = crate::project_id()?;
+    let client = pubsub::client::TopicAdmin::builder()
+        .with_tracing()
+        .build()
+        .await?;
+    let topic_id = random_topic_id(project.clone());
+
+    tracing::info!("testing create_topic()");
+    let topic = client
+        .create_topic()
+        .set_name(topic_id.clone())
+        .set_labels([("integration-test", "true")])
+        .send()
+        .await?;
+    tracing::info!("success on create_topic: {topic:?}");
+
+    Ok((client, topic))
+}
+
+pub async fn cleanup_test_topic(client: TopicAdmin, topic_name: String) -> Result<()> {
+    tracing::info!("testing delete_topic()");
+    client.delete_topic().set_topic(topic_name).send().await?;
+    tracing::info!("success on delete_topic");
+    Ok(())
+}

src/integration-tests/src/pubsub.rs

@@ -47,6 +47,18 @@ mod driver {
             .map_err(integration_tests::report_error)
     }
 
+    #[test_case(pubsub::client::TopicAdmin::builder(); "default")]
+    #[test_case(pubsub::client::TopicAdmin::builder().with_tracing(); "with tracing enabled")]
+    #[test_case(pubsub::client::TopicAdmin::builder().with_retry_policy(retry_policy()); "with retry enabled")]
+    #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    async fn run_pubsub_basic_topic(
+        builder: pubsub::builder::topic_admin::ClientBuilder,
+    ) -> integration_tests::Result<()> {
+        integration_tests::pubsub::basic_topic(builder)
+            .await
+            .map_err(integration_tests::report_error)
+    }
+
     #[test_case(sm::client::SecretManagerService::builder(); "default")]
     #[test_case(sm::client::SecretManagerService::builder().with_tracing(); "with tracing enabled")]
     #[test_case(sm::client::SecretManagerService::builder().with_retry_policy(retry_policy()); "with retry enabled")]