Make request level overrides take precedence

Author: mtdowling

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

@@ -78,24 +78,17 @@ protected <I extends SerializableStruct, O extends SerializableStruct> Completab
     ) {
         ClientPipeline<?, ?> callPipeline = pipeline;
         IdentityResolvers callIdentityResolvers = identityResolvers;
-        ClientConfig callConfig = config;
         ClientInterceptor callInterceptor = interceptor;
 
-        // Apply the given override before potentially applying interceptor based overrides.
-        var needsRebuild = false;
+        // First apply overrides from interceptors.
+        ClientConfig callConfig = callInterceptor.modifyBeforeCall(new CallHook<>(operation, config, input));
+        // Overrides given per/operation take precedence over interceptors.
         if (overrideConfig != null) {
-            needsRebuild = true;
             callConfig = callConfig.withRequestOverride(overrideConfig);
-            callInterceptor = ClientInterceptor.chain(callConfig.interceptors());
-        }
-
-        var updatedConfig = callInterceptor.modifyBeforeCall(new CallHook<>(operation, callConfig, input));
-        if (updatedConfig != callConfig) {
-            needsRebuild = true;
-            callConfig = updatedConfig;
         }
 
-        if (needsRebuild) {
+        // Rebuild the pipeline, resolvers, etc if the config changed.
+        if (callConfig != config) {
             callPipeline = ClientPipeline.of(callConfig.protocol(), callConfig.transport());
             callInterceptor = ClientInterceptor.chain(callConfig.interceptors());
             callIdentityResolvers = IdentityResolvers.of(callConfig.identityResolvers());

client/client-core/src/test/java/software/amazon/smithy/java/client/core/ClientTest.java

@@ -156,7 +156,7 @@ public void readBeforeExecution(InputHook<?, ?> hook) {
     }
 
     @Test
-    public void allowsInterceptorRequestOverridesOnOtherOverrides() throws URISyntaxException {
+    public void requestOverridesPerCallTakePrecedence() throws URISyntaxException {
         var queue = new MockQueue();
         queue.enqueue(HttpResponse.builder().statusCode(200).build());
         var id = "abc";
@@ -169,8 +169,9 @@ public void allowsInterceptorRequestOverridesOnOtherOverrides() throws URISyntax
                 .addPlugin(config -> config.addInterceptor(new ClientInterceptor() {
                     @Override
                     public ClientConfig modifyBeforeCall(CallHook<?, ?> hook) {
+                        // Note that the overrides given to the call itself will override interceptors.
                         var override = RequestOverrideConfig.builder()
-                                .putConfig(CallContext.APPLICATION_ID, id)
+                                .putConfig(CallContext.APPLICATION_ID, "foo")
                                 .build();
                         return hook.config().withRequestOverride(override);
                     }
@@ -190,7 +191,7 @@ public void readBeforeExecution(InputHook<?, ?> hook) {
                 Document.ofObject(new HashMap<>()),
                 RequestOverrideConfig.builder()
                         .putConfig(CallContext.API_CALL_TIMEOUT, Duration.ofMinutes(2))
-                        .putConfig(CallContext.APPLICATION_ID, "foo") // this will be overridden in the interceptor
+                        .putConfig(CallContext.APPLICATION_ID, id) // this will be take precedence
                         .build());
     }
 }