Add event stream media type to OpenAPI

smithy-model/src/main/java/software/amazon/smithy/model/knowledge/HttpBindingIndex.java

@@ -32,6 +32,7 @@
 import software.amazon.smithy.model.shapes.StructureShape;
 import software.amazon.smithy.model.shapes.ToShapeId;
 import software.amazon.smithy.model.traits.ErrorTrait;
+import software.amazon.smithy.model.traits.EventStreamTrait;
 import software.amazon.smithy.model.traits.HttpErrorTrait;
 import software.amazon.smithy.model.traits.HttpHeaderTrait;
 import software.amazon.smithy.model.traits.HttpLabelTrait;
@@ -252,6 +253,20 @@ public TimestampFormatTrait.Format determineTimestampFormat(
                 });
     }
 
+    /**
+     * Returns the expected request Content-Type of the given operation.
+     *
+     * <p>See {@link #determineRequestContentType(ToShapeId, String, String)}
+     * for documentation on how the content-type is resolved.
+     *
+     * @param operation Operation to determine the content-type of.
+     * @param documentContentType Content-Type to use for protocol documents.
+     * @return Returns the optionally resolved content-type of the request.
+     */
+    public Optional<String> determineRequestContentType(ToShapeId operation, String documentContentType) {
+        return determineRequestContentType(operation, documentContentType, null);
+    }
+
     /**
      * Returns the expected request Content-Type of the given operation.
      *
@@ -260,26 +275,48 @@ public TimestampFormatTrait.Format determineTimestampFormat(
      * to the payload, then the following checks are made:
      *
      * <ul>
+     *     <li>If the payload has the {@link EventStreamTrait}, then the
+     *     {@code eventStreamContentType} is returned.</li>
+     *     <li>If the targeted shape is a structure or document type, then
+     *     the {@code documentContentType} is returned.</li>
      *     <li>If the targeted shape has the {@link MediaTypeTrait}, then
      *     the value of the trait is returned.</li>
      *     <li>If the targeted shape is a blob, then "application/octet-stream"
      *     is returned.</li>
      *     <li>If the targeted shape is a string, then "text/plain" is
      *     returned.</li>
-     *     <li>If the targeted shape is a structure or document type, then
-     *     the {@code documentContentType} is returned.</li>
      * </ul>
      *
      * <p>If no members are sent in the payload, an empty Optional is
      * returned.
      *
      * @param operation Operation to determine the content-type of.
      * @param documentContentType Content-Type to use for protocol documents.
+     * @param eventStreamContentType Content-Type to use for event streams.
      * @return Returns the optionally resolved content-type of the request.
      */
-    public Optional<String> determineRequestContentType(ToShapeId operation, String documentContentType) {
-        String contentType = determineContentType(getRequestBindings(operation).values(), documentContentType);
-        return Optional.ofNullable(contentType);
+    public Optional<String> determineRequestContentType(
+            ToShapeId operation,
+            String documentContentType,
+            String eventStreamContentType
+    ) {
+        Collection<HttpBinding> bindings = getRequestBindings(operation).values();
+        return Optional.ofNullable(determineContentType(bindings, documentContentType, eventStreamContentType));
+    }
+
+    /**
+     * Returns the expected response Content-Type of the given operation
+     * or error.
+     *
+     * <p>See {@link #determineResponseContentType(ToShapeId, String, String)}
+     * for documentation on how the content-type is resolved.
+     *
+     * @param operationOrError Operation or error to determine the content-type of.
+     * @param documentContentType Content-Type to use for protocol documents.
+     * @return Returns the optionally resolved content-type of the response.
+     */
+    public Optional<String> determineResponseContentType(ToShapeId operationOrError, String documentContentType) {
+        return determineResponseContentType(operationOrError, documentContentType, null);
     }
 
     /**
@@ -291,50 +328,65 @@ public Optional<String> determineRequestContentType(ToShapeId operation, String
      * to the payload, then the following checks are made:
      *
      * <ul>
+     *     <li>If the payload has the {@link EventStreamTrait}, then the
+     *     {@code eventStreamContentType} is returned.</li>
+     *     <li>If the targeted shape is a structure or document type, then
+     *     the {@code documentContentType} is returned.</li>
      *     <li>If the targeted shape has the {@link MediaTypeTrait}, then
      *     the value of the trait is returned.</li>
      *     <li>If the targeted shape is a blob, then "application/octet-stream"
      *     is returned.</li>
      *     <li>If the targeted shape is a string, then "text/plain" is
      *     returned.</li>
-     *     <li>If the targeted shape is a structure or document type, then
-     *     the {@code documentContentType} is returned.</li>
      * </ul>
      *
      * <p>If no members are sent in the payload, an empty Optional is
      * returned.
      *
      * @param operationOrError Operation or error to determine the content-type of.
      * @param documentContentType Content-Type to use for protocol documents.
+     * @param eventStreamContentType Content-Type used for event streams.
      * @return Returns the optionally resolved content-type of the response.
      */
-    public Optional<String> determineResponseContentType(ToShapeId operationOrError, String documentContentType) {
-        String contentType = determineContentType(getResponseBindings(operationOrError).values(), documentContentType);
-        return Optional.ofNullable(contentType);
+    public Optional<String> determineResponseContentType(
+            ToShapeId operationOrError,
+            String documentContentType,
+            String eventStreamContentType
+    ) {
+        Collection<HttpBinding> bindings = getResponseBindings(operationOrError).values();
+        return Optional.ofNullable(determineContentType(bindings, documentContentType, eventStreamContentType));
     }
 
-    private String determineContentType(Collection<HttpBinding> bindings, String documentContentType) {
+    private String determineContentType(
+            Collection<HttpBinding> bindings,
+            String documentContentType,
+            String eventStreamContentType
+    ) {
         for (HttpBinding binding : bindings) {
             if (binding.getLocation() == HttpBinding.Location.DOCUMENT) {
                 return documentContentType;
             }
 
             if (binding.getLocation() == HttpBinding.Location.PAYLOAD) {
-                Shape target = model.getShape(binding.getMember().getTarget()).orElse(null);
+                if (binding.getMember().hasTrait(EventStreamTrait.class)) {
+                    return eventStreamContentType;
+                }
 
+                Shape target = model.getShape(binding.getMember().getTarget()).orElse(null);
                 if (target == null) {
+                    // Can't determine the content-type because the model is broken :(
+                    // Let other parts of the validation system point this out.
                     break;
-                }
-
-                // Use the @mediaType trait if available.
-                if (target.getTrait(MediaTypeTrait.class).isPresent()) {
+                } else if (target.isDocumentShape() || target.isStructureShape()) {
+                    // Document type and structure targets are always the document content-type.
+                    return documentContentType;
+                } else if (target.getTrait(MediaTypeTrait.class).isPresent()) {
+                    // Use the @mediaType trait if available.
                     return target.getTrait(MediaTypeTrait.class).get().getValue();
                 } else if (target.isBlobShape()) {
                     return "application/octet-stream";
                 } else if (target.isStringShape()) {
                     return "text/plain";
-                } else if (target.isDocumentShape() || target.isStructureShape()) {
-                    return documentContentType;
                 }
             }
         }

smithy-model/src/test/java/software/amazon/smithy/model/knowledge/HttpBindingIndexTest.java

@@ -260,14 +260,33 @@ public void resolvesBlobBodyContentType() {
     }
 
     @Test
-    public void resolvesMediaTypeContentType() {
+    public void resolvesMediaType() {
         HttpBindingIndex index = model.getKnowledge(HttpBindingIndex.class);
         ShapeId operation = ShapeId.from("ns.foo#ServiceOperationWithMediaType");
         Optional<String> contentType = index.determineResponseContentType(operation, "application/json");
 
         assertThat(contentType, equalTo(Optional.of("application/xml")));
     }
 
+    @Test
+    public void resolvesResponseEventStreamMediaType() {
+        HttpBindingIndex index = model.getKnowledge(HttpBindingIndex.class);
+        ShapeId operation = ShapeId.from("ns.foo#ServiceOperationWithEventStream");
+        String expected = "application/vnd.amazon.eventstream";
+        Optional<String> contentType = index.determineResponseContentType(operation, "ignore/me", expected);
+
+        assertThat(contentType, equalTo(Optional.of(expected)));
+    }
+
+    @Test
+    public void resolvesDocumentMediaType() {
+        HttpBindingIndex index = model.getKnowledge(HttpBindingIndex.class);
+        ShapeId operation = ShapeId.from("ns.foo#ServiceOperationExplicitMembers");
+        Optional<String> contentType = index.determineResponseContentType(operation, "application/json");
+
+        assertThat(contentType, equalTo(Optional.of("application/json")));
+    }
+
     private static MemberShape expectMember(Model model, String id) {
         ShapeId shapeId = ShapeId.from(id);
         return model.expectShape(shapeId).asMemberShape().get();

smithy-model/src/test/resources/software/amazon/smithy/model/knowledge/http-index.json

@@ -19,6 +19,9 @@
                 },
                 {
                     "target": "ns.foo#WithLabels"
+                },
+                {
+                    "target": "ns.foo#ServiceOperationWithEventStream"
                 }
             ]
         },
@@ -288,6 +291,39 @@
             "value": {
                 "target": "smithy.api#String"
             }
+        },
+        "ns.foo#ServiceOperationWithEventStream": {
+            "type": "operation",
+            "output": {
+                "target": "ns.foo#ServiceOperationWithEventStreamOutput"
+            },
+            "traits": {
+                "smithy.api#http": {
+                    "uri": "/ServiceOperationWithEventStream",
+                    "method": "POST",
+                    "code": 200
+                }
+            }
+        },
+        "ns.foo#ServiceOperationWithEventStreamOutput": {
+            "type": "structure",
+            "members": {
+                "events": {
+                    "target": "ns.foo#EventStream",
+                    "traits": {
+                        "smithy.api#httpPayload": true,
+                        "smithy.api#eventStream": true
+                    }
+                }
+            }
+        },
+        "ns.foo#EventStream": {
+            "type": "structure",
+            "members": {
+                "foo": {
+                    "target": "smithy.api#String"
+                }
+            }
         }
     }
 }

smithy-openapi/src/main/java/software/amazon/smithy/openapi/fromsmithy/mappers/UnsupportedTraits.java

@@ -35,8 +35,7 @@
  */
 public final class UnsupportedTraits implements OpenApiMapper {
     private static final Logger LOGGER = Logger.getLogger(UnsupportedTraits.class.getName());
-    private static final Set<String> TRAITS = SetUtils.of(
-            "eventStream", "eventPayload", "eventHeader", "streaming");
+    private static final Set<String> TRAITS = SetUtils.of("endpoint", "hostLabel");
 
     @Override
     public byte getOrder() {