Fix codegen to ignore httpLabel on non-input shapes per Smithy spec

codegen/src/main/java/software/amazon/awssdk/codegen/AddShapes.java

@@ -342,38 +342,54 @@
      */
     private boolean isGreedy(Shape parentShape, Map<String, Shape> allC2jShapes, ParameterHttpMapping mapping) {
         if (mapping.getLocation() == Location.URI) {
-            // If the location is URI we can assume the parent shape is an input shape.
-            String requestUri = findRequestUri(parentShape, allC2jShapes);
-            if (requestUri.contains(String.format("{%s+}", mapping.getMarshallLocationName()))) {
+            Optional<String> requestUri = findRequestUri(parentShape, allC2jShapes);
+            if (requestUri.isPresent()
+                && requestUri.get().contains(String.format("{%s+}", mapping.getMarshallLocationName()))) {
                 return true;
             }
         }
         return false;
     }
 
     /**
-     * Given an input shape, finds the Request URI for the operation that input is referenced from.
+     * Given a shape, finds the Request URI for the operation that references it as input.
+     * Returns empty if the shape is not a direct operation input.
+     * Throws if the shape is a direct operation input but the operation is missing a requestUri.
      *
-     * @param parentShape  Input shape to find operation's request URI for.
+     * @param parentShape  Shape to find operation's request URI for.
      * @param allC2jShapes All shapes in the service model.
-     * @return Request URI for operation.
-     * @throws RuntimeException If operation can't be found.
+     * @return Request URI for operation, or empty if the shape is not a direct operation input.
+     * @throws ModelInvalidException If the shape is a direct operation input but requestUri is missing.
      */
-    private String findRequestUri(Shape parentShape, Map<String, Shape> allC2jShapes) {
+    private Optional<String> findRequestUri(Shape parentShape, Map<String, Shape> allC2jShapes) {
         Optional<Operation> operation = builder.getService().getOperations().values().stream()
                                                .filter(o -> o.getInput() != null)
                                                .filter(o -> allC2jShapes.get(o.getInput().getShape()).equals(parentShape))
                                                .findFirst();
 
-        return operation.map(o -> o.getHttp().getRequestUri())
-                        .orElseThrow(() -> {
-                            String detailMsg = "Could not find request URI for input shape for operation: " + operation;
-                            ValidationEntry entry =
-                                new ValidationEntry().withErrorId(ValidationErrorId.REQUEST_URI_NOT_FOUND)
-                                                     .withDetailMessage(detailMsg)
-                                                     .withSeverity(ValidationErrorSeverity.DANGER);
-                            return ModelInvalidException.builder().validationEntries(Collections.singletonList(entry)).build();
-                        });
+        if (!operation.isPresent()) {
+            // Not a direct operation input shape, should be ignored.
+            // https://smithy.io/2.0/spec/http-bindings.html#httplabel-is-only-used-on-top-level-input
+            return Optional.empty();
+        }
+
+        String requestUri = operation.get().getHttp().getRequestUri();
+        if (requestUri == null) {
+            String shapeName = allC2jShapes.entrySet().stream()
+                .filter(e -> e.getValue().equals(parentShape))
+                .map(Map.Entry::getKey)
+                .findFirst()
+                .get();
+            String detailMsg = "Could not find request URI for input shape '" + shapeName
+                + "'. No operation was found that references this shape as its input.";
+            ValidationEntry entry =
+                new ValidationEntry().withErrorId(ValidationErrorId.REQUEST_URI_NOT_FOUND)
+                                     .withDetailMessage(detailMsg)
+                                     .withSeverity(ValidationErrorSeverity.DANGER);
+            throw ModelInvalidException.builder().validationEntries(Collections.singletonList(entry)).build();
+        }
+
+        return Optional.of(requestUri);
     }
 
     private String deriveUnmarshallerLocationName(Shape memberShape, String memberName, Member member) {

codegen/src/test/java/software/amazon/awssdk/codegen/CodeGeneratorTest.java

@@ -16,6 +16,7 @@
 package software.amazon.awssdk.codegen;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatNoException;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
@@ -48,6 +49,7 @@
 import software.amazon.awssdk.codegen.poet.ClientTestModels;
 import software.amazon.awssdk.codegen.validation.ModelInvalidException;
 import software.amazon.awssdk.codegen.validation.ModelValidator;
+import software.amazon.awssdk.codegen.validation.ValidationEntry;
 import software.amazon.awssdk.codegen.validation.ValidationErrorId;
 
 public class CodeGeneratorTest {
@@ -176,6 +178,18 @@
             });
     }
 
+    @Test
+    void execute_uriLocationOnNonInputShape_isIgnored() throws IOException {
+        C2jModels models = C2jModels.builder()
+                                    .customizationConfig(CustomizationConfig.create())
+                                    .serviceModel(getUriOnNonInputShapeServiceModel())
+                                    .build();
+
+        // Per the Smithy spec, httpLabel on non-input shapes has no meaning and is simply ignored.
+        assertThatNoException().isThrownBy(
+            () -> generateCodeFromC2jModels(models, outputDir, true, Collections.emptyList()));
+    }
+
     @Test
     void execute_operationHasNoRequestUri_throwsValidationError() throws IOException {
         C2jModels models = C2jModels.builder()
@@ -244,6 +258,11 @@
         return Jackson.load(ServiceModel.class, json);
     }
 
+    private ServiceModel getUriOnNonInputShapeServiceModel() throws IOException {
+        String json = resourceAsString("uri-on-non-input-shape-service.json");
+        return Jackson.load(ServiceModel.class, json);
+    }
+
     private String resourceAsString(String name) throws IOException {
         ByteArrayOutputStream baos;
         try (InputStream resourceAsStream = getClass().getResourceAsStream(name)) {

codegen/src/test/resources/software/amazon/awssdk/codegen/uri-on-non-input-shape-service.json

@@ -0,0 +1,57 @@
+{
+  "version": "2.0",
+  "metadata": {
+    "apiVersion": "2010-05-08",
+    "endpointPrefix": "json-service-endpoint",
+    "globalEndpoint": "json-service.amazonaws.com",
+    "protocol": "rest-json",
+    "serviceAbbreviation": "Rest Json Service",
+    "serviceFullName": "Some Service That Uses Rest-Json Protocol",
+    "serviceId": "Rest Json Service",
+    "signingName": "json-service",
+    "signatureVersion": "v4",
+    "uid": "json-service-2010-05-08",
+    "xmlNamespace": "https://json-service.amazonaws.com/doc/2010-05-08/"
+  },
+  "operations": {
+    "SomeOperation": {
+      "name": "SomeOperation",
+      "http": {
+        "method": "POST",
+        "requestUri": "/things/{thingId}"
+      },
+      "input": {
+        "shape": "SomeOperationRequest"
+      }
+    }
+  },
+  "shapes": {
+    "SomeOperationRequest": {
+      "type": "structure",
+      "members": {
+        "thingId": {
+          "shape": "String",
+          "location": "uri",
+          "locationName": "thingId"
+        },
+        "options": {
+          "shape": "NestedOptions"
+        }
+      }
+    },
+    "NestedOptions": {
+      "type": "structure",
+      "members": {
+        "pageSize": {
+          "shape": "String",
+          "location": "uri",
+          "locationName": "pageSize"
+        }
+      }
+    },
+    "String": {
+      "type": "string"
+    }
+  },
+  "documentation": "A service with a uri-bound member on a non-input shape"
+}