Add MockPlugin (#505)

The MockPlugin is used to intercept requests and return canned
responses, shapes, or exceptions. Various tests that previously did
something similar to this have been updated to use it.

Other minor fixes were made to make this happen:
1. ClientTransport is not needed to be applied manually in Client.
2. ClientTransport is applied eagerly as a plugin when applied to the
   ClientConfig.Builder.
3. Changed a Boolean to boolean in UriTreeMatcherMapBuilder to avoid
   an NPE.
4. ClientProtocol now uses a ShapeId instead of a String.
5. Added a method to DynamicClient to create a SerializableStruct from
   the converted model.
6. Added a helper method to detect the correct HTTP status of an error.
7. Fixed a bug in the HttpBindingSerializer where the status code wasn't
   being properly set for errors (was always 200).

Author: mtdowling

aws/aws-client-http/build.gradle.kts

@@ -13,5 +13,6 @@ dependencies {
     api(project(":http-api"))
 
     testImplementation(project(":dynamic-client"))
+    testImplementation(project(":mock-client-plugin"))
     testImplementation(project(":aws:client-awsjson"))
 }

aws/aws-client-http/src/test/java/software/amazon/smithy/java/aws/client/http/AmzSdkRequestPluginTest.java

@@ -6,23 +6,17 @@
 package software.amazon.smithy.java.aws.client.http;
 
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.contains;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasSize;
 
 import java.time.Duration;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.atomic.AtomicInteger;
 import org.junit.jupiter.api.Test;
 import software.amazon.smithy.java.aws.client.awsjson.AwsJson1Protocol;
-import software.amazon.smithy.java.client.core.ClientTransport;
-import software.amazon.smithy.java.client.core.MessageExchange;
 import software.amazon.smithy.java.client.core.auth.scheme.AuthSchemeResolver;
 import software.amazon.smithy.java.client.core.endpoint.EndpointResolver;
-import software.amazon.smithy.java.client.core.interceptors.ClientInterceptor;
-import software.amazon.smithy.java.client.core.interceptors.RequestHook;
-import software.amazon.smithy.java.client.http.HttpMessageExchange;
-import software.amazon.smithy.java.context.Context;
+import software.amazon.smithy.java.client.http.mock.MockPlugin;
+import software.amazon.smithy.java.client.http.mock.MockQueue;
 import software.amazon.smithy.java.dynamicclient.DynamicClient;
-import software.amazon.smithy.java.http.api.HttpRequest;
 import software.amazon.smithy.java.http.api.HttpResponse;
 import software.amazon.smithy.java.io.datastream.DataStream;
 import software.amazon.smithy.java.retries.api.AcquireInitialTokenRequest;
@@ -61,54 +55,17 @@ private static final class Token implements RetryToken {}
 
     @Test
     public void injectsHeader() {
-        AtomicInteger attempt = new AtomicInteger(0);
+        var mockQueue = new MockQueue();
+        var mock = MockPlugin.builder().addQueue(mockQueue).build();
 
         var client = DynamicClient.builder()
             .service(SERVICE)
             .model(MODEL)
             .protocol(new AwsJson1Protocol(SERVICE))
+            .addPlugin(mock)
             .authSchemeResolver(AuthSchemeResolver.NO_AUTH)
-            .transport(new ClientTransport<HttpRequest, HttpResponse>() {
-                @Override
-                public MessageExchange<HttpRequest, HttpResponse> messageExchange() {
-                    return HttpMessageExchange.INSTANCE;
-                }
-
-                @Override
-                public CompletableFuture<HttpResponse> send(Context context, HttpRequest request) {
-                    var i = attempt.incrementAndGet();
-                    if (i == 1) {
-                        return CompletableFuture.completedFuture(
-                            HttpResponse.builder()
-                                .statusCode(429)
-                                .body(DataStream.ofString("{\"__type\":\"InvalidSprocketId\"}"))
-                                .build()
-                        );
-                    } else if (i == 2) {
-                        return CompletableFuture.completedFuture(
-                            HttpResponse.builder()
-                                .statusCode(200)
-                                .body(DataStream.ofString("{\"id\":\"1\"}"))
-                                .build()
-                        );
-                    } else {
-                        throw new IllegalStateException("Unexpected attempt " + i);
-                    }
-                }
-            })
             .endpointResolver(EndpointResolver.staticEndpoint("https://foo.com"))
             .addPlugin(new AmzSdkRequestPlugin())
-            .addInterceptor(new ClientInterceptor() {
-                @Override
-                public void readBeforeTransmit(RequestHook<?, ?, ?> hook) {
-                    var request = (HttpRequest) hook.request();
-                    var i = attempt.get();
-                    assertThat(
-                        request.headers().allValues("amz-sdk-request"),
-                        contains("attempt=" + (i + 1) + "; max=3")
-                    );
-                }
-            })
             .retryStrategy(new RetryStrategy() {
                 @Override
                 public AcquireInitialTokenResponse acquireInitialToken(AcquireInitialTokenRequest request) {
@@ -137,6 +94,24 @@ public Builder toBuilder() {
             })
             .build();
 
+        mockQueue.enqueue(
+            HttpResponse.builder()
+                .statusCode(429)
+                .body(DataStream.ofString("{\"__type\":\"InvalidSprocketId\"}"))
+                .build()
+        );
+        mockQueue.enqueue(
+            HttpResponse.builder()
+                .statusCode(200)
+                .body(DataStream.ofString("{\"id\":\"1\"}"))
+                .build()
+        );
+
         client.call("CreateSprocket");
+
+        var requests = mock.getRequests();
+        assertThat(requests, hasSize(2));
+        assertThat(requests.get(0).request().headers().firstValue("amz-sdk-request"), equalTo("attempt=1; max=3"));
+        assertThat(requests.get(1).request().headers().firstValue("amz-sdk-request"), equalTo("attempt=2; max=3"));
     }
 }

aws/client-awsjson/src/main/java/software/amazon/smithy/java/aws/client/awsjson/AwsJsonProtocol.java

@@ -40,7 +40,7 @@ abstract sealed class AwsJsonProtocol extends HttpClientProtocol permits AwsJson
      *                discriminator of documents that use relative shape IDs.
      */
     public AwsJsonProtocol(ShapeId trait, ShapeId service) {
-        super(trait.toString());
+        super(trait);
         this.service = service;
         this.codec = JsonCodec.builder().defaultNamespace(service.getNamespace()).build();
 

aws/client-restjson/src/main/java/software/amazon/smithy/java/aws/client/restjson/RestJsonClientProtocol.java

@@ -39,7 +39,7 @@ public final class RestJsonClientProtocol extends HttpBindingClientProtocol<AwsE
      *                relative shape IDs.
      */
     public RestJsonClientProtocol(ShapeId service) {
-        super(RestJson1Trait.ID.toString());
+        super(RestJson1Trait.ID);
 
         this.codec = JsonCodec.builder()
             .useJsonName(true)

aws/client-restxml/src/main/java/software/amazon/smithy/java/aws/client/restxml/RestXmlClientProtocol.java

@@ -39,7 +39,7 @@ public final class RestXmlClientProtocol extends HttpBindingClientProtocol<AwsEv
      *                relative shape IDs.
      */
     public RestXmlClientProtocol(ShapeId service) {
-        super(RestXmlTrait.ID.toString());
+        super(RestXmlTrait.ID);
 
         this.codec = XmlCodec.builder().build();
         this.errorDeserializer = HttpErrorDeserializer.builder()

aws/client-rpcv2-cbor-protocol/src/main/java/software/amazon/smithy/java/client/rpcv2/RpcV2CborProtocol.java

@@ -39,7 +39,7 @@ public final class RpcV2CborProtocol extends HttpClientProtocol {
     private final HttpErrorDeserializer errorDeserializer;
 
     public RpcV2CborProtocol(ShapeId service) {
-        super(Rpcv2CborTrait.ID.toString());
+        super(Rpcv2CborTrait.ID);
         this.service = service;
         this.errorDeserializer = HttpErrorDeserializer.builder()
             .codec(CBOR_CODEC)

client-core/build.gradle.kts

@@ -16,4 +16,5 @@ dependencies {
 
     testImplementation(project(":dynamic-client"))
     testImplementation(project(":aws:client-restjson"))
+    testImplementation(project(":mock-client-plugin"))
 }

client-core/src/main/java/software/amazon/smithy/java/client/core/Client.java

@@ -40,7 +40,7 @@ protected Client(Builder<?, ?> builder) {
 
         // Resolve the transport and apply it as a plugin before user-defined plugins, allowing user-defined plugins
         // to supersede and functionality of plugins applied by transports.
-        configBuilder.resolveTransport().applyPlugin(configBuilder.transport());
+        configBuilder.resolveTransport();
 
         for (ClientPlugin plugin : builder.plugins) {
             configBuilder.applyPlugin(plugin);

client-core/src/main/java/software/amazon/smithy/java/client/core/ClientConfig.java

@@ -351,6 +351,7 @@ public String retryScope() {
          */
         public Builder transport(ClientTransport<?, ?> transport) {
             this.transport = transport;
+            applyPlugin(transport);
             return this;
         }
 
@@ -367,10 +368,6 @@ public Builder resolveTransport() {
             if (transport == null) {
                 transport(discoverTransport(protocol));
             }
-            // If the transport has not yet been applied as a plugin, apply it now.
-            if (!appliedPlugins.contains(transport.getClass())) {
-                applyPlugin(transport);
-            }
             return this;
         }
 

client-core/src/main/java/software/amazon/smithy/java/client/core/ClientProtocol.java

@@ -13,6 +13,7 @@
 import software.amazon.smithy.java.core.schema.ApiOperation;
 import software.amazon.smithy.java.core.schema.SerializableStruct;
 import software.amazon.smithy.java.core.serde.TypeRegistry;
+import software.amazon.smithy.model.shapes.ShapeId;
 
 /**
  * Handles request and response serialization.
@@ -26,7 +27,7 @@ public interface ClientProtocol<RequestT, ResponseT> {
      *
      * @return the protocol ID.
      */
-    String id();
+    ShapeId id();
 
     /**
      * Get the message exchange.