feat(cbor): add protocol resolution priority system

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/DirectedTypeScriptCodegen.java

@@ -18,7 +18,7 @@
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -136,7 +136,9 @@ private ProtocolGenerator resolveProtocolGenerator(
             TypeScriptSettings settings
     ) {
         // Collect all of the supported protocol generators.
-        Map<ShapeId, ProtocolGenerator> generators = new HashMap<>();
+        // Preserve insertion order as default priority order.
+        Map<ShapeId, ProtocolGenerator> generators = new LinkedHashMap<>();
+
         for (TypeScriptIntegration integration : integrations) {
             for (ProtocolGenerator generator : integration.getProtocolGenerators()) {
                 generators.put(generator.getProtocol(), generator);

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/TypeScriptSettings.java

@@ -15,6 +15,7 @@
 
 package software.amazon.smithy.typescript.codegen;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -36,6 +37,7 @@
 import software.amazon.smithy.model.shapes.ShapeId;
 import software.amazon.smithy.model.traits.DefaultTrait;
 import software.amazon.smithy.model.traits.RequiredTrait;
+import software.amazon.smithy.typescript.codegen.protocols.ProtocolPriority;
 import software.amazon.smithy.utils.SmithyUnstableApi;
 
 /**
@@ -450,8 +452,13 @@ public ShapeId resolveServiceProtocol(Model model, ServiceShape service, Set<Sha
                     + "generate in smithy-build.json to generate this service.");
         }
 
-        return resolvedProtocols.stream()
-                .filter(supportedProtocols::contains)
+        List<ShapeId> protocolPriority = ProtocolPriority.getProtocolPriority(service.toShapeId());
+        List<ShapeId> protocolPriorityList = protocolPriority != null && !protocolPriority.isEmpty()
+            ? protocolPriority
+            : new ArrayList<>(supportedProtocols);
+
+        return protocolPriorityList.stream()
+                .filter(resolvedProtocols::contains)
                 .findFirst()
                 .orElseThrow(() -> new UnresolvableProtocolException(String.format(
                         "The %s service supports the following unsupported protocols %s. The following protocol "

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/protocols/ProtocolPriority.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.typescript.codegen.protocols;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import software.amazon.smithy.model.shapes.ShapeId;
+
+
+/**
+ * Allows customization of protocol selection for specific services or a global default ordering.
+ */
+public final class ProtocolPriority {
+    private static final Map<ShapeId, List<ShapeId>> SERVICE_PROTOCOL_PRIORITY_CUSTOMIZATIONS = new HashMap<>();
+    private static List<ShapeId> customDefaultPriority = null;
+
+    private ProtocolPriority() {}
+
+    /**
+     * @param serviceShapeId - service scope.
+     * @param protocolPriorityOrder - priority order of protocols.
+     */
+    public static void setProtocolPriority(ShapeId serviceShapeId, List<ShapeId> protocolPriorityOrder) {
+        SERVICE_PROTOCOL_PRIORITY_CUSTOMIZATIONS.put(serviceShapeId, protocolPriorityOrder);
+    }
+
+    /**
+     * @param defaultProtocolPriorityOrder - use for all services that don't have a more specific priority order.
+     */
+    public static void setCustomDefaultProtocolPriority(List<ShapeId> defaultProtocolPriorityOrder) {
+        customDefaultPriority = new ArrayList<>(defaultProtocolPriorityOrder);
+    }
+
+    /**
+     * @param serviceShapeId - service scope.
+     * @return priority order of protocols or null if no override exists.
+     */
+    public static List<ShapeId> getProtocolPriority(ShapeId serviceShapeId) {
+        return SERVICE_PROTOCOL_PRIORITY_CUSTOMIZATIONS.getOrDefault(
+            serviceShapeId,
+            customDefaultPriority != null ? new ArrayList<>(customDefaultPriority) : null
+        );
+    }
+
+    /**
+     * @param serviceShapeId - to unset.
+     */
+    public static void deleteProtocolPriority(ShapeId serviceShapeId) {
+        SERVICE_PROTOCOL_PRIORITY_CUSTOMIZATIONS.remove(serviceShapeId);
+    }
+
+    /**
+     * Unset the custom default priority order.
+     */
+    public static void deleteCustomDefaultProtocolPriority() {
+        customDefaultPriority = null;
+    }
+}

smithy-typescript-codegen/src/test/java/software/amazon/smithy/typescript/codegen/TypeScriptSettingsTest.java

@@ -1,20 +1,31 @@
 package software.amazon.smithy.typescript.codegen;
 
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.stream.Stream;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
 import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.knowledge.ServiceIndex;
 import software.amazon.smithy.model.node.Node;
 import software.amazon.smithy.model.node.ObjectNode;
+import software.amazon.smithy.model.shapes.ServiceShape;
 import software.amazon.smithy.model.shapes.ShapeId;
-
-import java.util.stream.Stream;
+import software.amazon.smithy.typescript.codegen.protocols.ProtocolPriority;
+import software.amazon.smithy.utils.MapUtils;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
 
+@ExtendWith(MockitoExtension.class)
 public class TypeScriptSettingsTest {
 
     @Test
@@ -87,6 +98,121 @@ private static Stream<Arguments> providePackageDescriptionTestCases() {
         );
     }
 
+    @Test
+    public void resolveServiceProtocol(@Mock Model model,
+                                       @Mock ServiceShape service,
+                                       @Mock ServiceIndex serviceIndex) {
+        TypeScriptSettings subject = new TypeScriptSettings();
+
+        // note: these are mock protocol names.
+        ShapeId rpcv2Cbor = ShapeId.from("namespace#rpcv2Cbor");
+        ShapeId json1_0 = ShapeId.from("namespace#json1_0");
+        ShapeId json1_1 = ShapeId.from("namespace#json1_1");
+        ShapeId restJson1 = ShapeId.from("namespace#restJson1");
+        ShapeId restXml = ShapeId.from("namespace#restXml");
+        ShapeId query = ShapeId.from("namespace#query");
+        ShapeId serviceQuery = ShapeId.from("namespace#serviceQuery");
+
+        when(model.getKnowledge(any(), any())).thenReturn(serviceIndex);
+        ShapeId serviceShapeId = ShapeId.from("namespace#Service");
+        when(service.toShapeId()).thenReturn(serviceShapeId);
+
+        LinkedHashSet<ShapeId> protocolShapeIds = new LinkedHashSet<>(
+            List.of(
+                json1_0, json1_1, restJson1, rpcv2Cbor, restXml, query, serviceQuery
+            )
+        );
+
+        {
+            // spec case 1.
+            when(serviceIndex.getProtocols(service)).thenReturn(MapUtils.of(
+                rpcv2Cbor, null,
+                json1_0, null
+            ));
+            ShapeId protocol = subject.resolveServiceProtocol(model, service, protocolShapeIds);
+            // Note: JS customization JSON higher default priority than CBOR.
+            assertEquals(json1_0, protocol);
+        }
+
+        {
+            // spec case 2.
+            when(serviceIndex.getProtocols(service)).thenReturn(MapUtils.of(
+                rpcv2Cbor, null
+            ));
+            ShapeId protocol = subject.resolveServiceProtocol(model, service, protocolShapeIds);
+            assertEquals(rpcv2Cbor, protocol);
+        }
+
+        {
+            // spec case 3.
+            when(serviceIndex.getProtocols(service)).thenReturn(MapUtils.of(
+                rpcv2Cbor, null,
+                json1_0, null,
+                query, null
+            ));
+            ShapeId protocol = subject.resolveServiceProtocol(model, service, protocolShapeIds);
+            // Note: JS customization JSON higher default priority than CBOR.
+            assertEquals(json1_0, protocol);
+        }
+
+        {
+            // spec case 4.
+            when(serviceIndex.getProtocols(service)).thenReturn(MapUtils.of(
+                json1_0, null,
+                query, null
+            ));
+            ShapeId protocol = subject.resolveServiceProtocol(model, service, protocolShapeIds);
+            assertEquals(json1_0, protocol);
+        }
+
+        {
+            // spec case 5.
+            when(serviceIndex.getProtocols(service)).thenReturn(MapUtils.of(
+                query, null
+            ));
+            ShapeId protocol = subject.resolveServiceProtocol(model, service, protocolShapeIds);
+            assertEquals(query, protocol);
+        }
+
+        {
+            // service override, non-spec
+            when(serviceIndex.getProtocols(service)).thenReturn(MapUtils.of(
+                json1_0, null,
+                json1_1, null,
+                restJson1, null,
+                rpcv2Cbor, null,
+                restXml, null,
+                query, null,
+                serviceQuery, null
+            ));
+            ProtocolPriority.setProtocolPriority(serviceShapeId, List.of(
+                serviceQuery, rpcv2Cbor, json1_1, restJson1, restXml, query
+            ));
+            ShapeId protocol = subject.resolveServiceProtocol(model, service, protocolShapeIds);
+            ProtocolPriority.deleteProtocolPriority(serviceShapeId);
+            assertEquals(serviceQuery, protocol);
+        }
+
+        {
+            // global default override
+            when(serviceIndex.getProtocols(service)).thenReturn(MapUtils.of(
+                json1_0, null,
+                json1_1, null,
+                restJson1, null,
+                rpcv2Cbor, null,
+                restXml, null,
+                query, null,
+                serviceQuery, null
+            ));
+            ProtocolPriority.setCustomDefaultProtocolPriority(List.of(
+                rpcv2Cbor, json1_1, restJson1, restXml, query
+            ));
+            ShapeId protocol = subject.resolveServiceProtocol(model, service, protocolShapeIds);
+            ProtocolPriority.deleteCustomDefaultProtocolPriority();
+            assertEquals(rpcv2Cbor, protocol);
+        }
+    }
+
     @Test
     public void resolvesSupportProtocols() {
         // TODO