chore: Add Showcase Callables IT (#1483)

* chore: Add Showcase Callables IT

* chore: Add test scope

* deps: update google http client dependencies to v1.43.1 (#1487)

* build(deps): update dependency org.apache.maven.plugins:maven-surefire-plugin to v3.0.0 (#1488)

Co-authored-by: Lawrence Qiu <lawrenceqiu@google.com>

* chore(main): release 2.15.3 (#1445)

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
Co-authored-by: Lawrence Qiu <lawrenceqiu@google.com>

* chore(main): release 2.15.4-SNAPSHOT (#1489)

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

* chore: Refactor paged logic

* chore: Format ITCallables

* chore: Format ITCallables

* chore: Fix to not found status code

* chore: Add HttpJson Unary Callable Showcase Test

* chore: Fix truth dependency

* chore: Update test name

* chore: Address code smell

* chore: Remove incorrect comment

* chore: Update test to CANCELLED

* chore: Clean up PR

---------

Co-authored-by: Mend Renovate <bot@renovateapp.com>
Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

showcase/gapic-showcase/pom.xml

@@ -165,7 +165,6 @@
       <artifactId>junit</artifactId>
       <scope>test</scope>
     </dependency>
-
     <dependency>
       <groupId>com.google.truth</groupId>
       <artifactId>truth</artifactId>

showcase/gapic-showcase/src/test/java/com/google/showcase/v1beta1/it/ITUnaryCallable.java

@@ -100,11 +100,29 @@ public void testGrpc_shutdown() {
   }
 
   @Test
-  public void testHttpJson() {
+  public void testHttpJson_receiveContent() {
     assertThat(echoHttpJson("http-echo?")).isEqualTo("http-echo?");
     assertThat(echoHttpJson("http-echo!")).isEqualTo("http-echo!");
   }
 
+  @Test
+  public void testHttpJson_serverResponseError_throwsException() {
+    EchoRequest requestWithServerError =
+        EchoRequest.newBuilder()
+            .setError(Status.newBuilder().setCode(StatusCode.Code.CANCELLED.ordinal()).build())
+            .build();
+    CancelledException exception =
+        assertThrows(CancelledException.class, () -> httpJsonClient.echo(requestWithServerError));
+    assertThat(exception.getStatusCode().getCode()).isEqualTo(StatusCode.Code.CANCELLED);
+  }
+
+  @Test
+  public void testHttpJson_shutdown() {
+    assertThat(httpJsonClient.isShutdown()).isFalse();
+    httpJsonClient.shutdown();
+    assertThat(httpJsonClient.isShutdown()).isTrue();
+  }
+
   private String echoGrpc(String value) {
     EchoResponse response = grpcClient.echo(EchoRequest.newBuilder().setContent(value).build());
     return response.getContent();