Use ordered sets for shape id sequences

smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/HttpChecksumTraitValidator.java

@@ -260,8 +260,8 @@ private List<ValidationEvent> validateResponseChecksumConfiguration(
         });
 
         // Check for header binding conflicts with each error shape.
-        if (!operation.getErrors().isEmpty()) {
-            for (ShapeId id : operation.getErrors()) {
+        if (!operation.getErrorsSet().isEmpty()) {
+            for (ShapeId id : operation.getErrorsSet()) {
                 StructureShape shape = model.expectShape(id, StructureShape.class);
                 events.addAll(validateHeaderConflicts(operation, shape));
             }

smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/clientendpointdiscovery/ClientEndpointDiscoveryValidator.java

@@ -138,7 +138,7 @@ private List<ValidationEvent> validateOperation(OperationShape operation, List<C
 
         return infos.stream()
                 .filter(discoveryInfo -> discoveryInfo.getOptionalError().isPresent())
-                .filter(discoveryInfo -> !operation.getErrors()
+                .filter(discoveryInfo -> !operation.getErrorsSet()
                         .contains(
                                 discoveryInfo.getOptionalError().get().getId()))
                 .map(discoveryInfo -> error(operation,

smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/protocols/ProtocolHttpPayloadValidator.java

@@ -76,7 +76,7 @@ private List<ValidationEvent> validateService(
             List<HttpBinding> responseBindings = bindingIndex.getResponseBindings(operation, Location.PAYLOAD);
             validateBindings(model, responseBindings).ifPresent(events::add);
 
-            for (ShapeId error : operation.getErrors()) {
+            for (ShapeId error : operation.getErrorsSet()) {
                 List<HttpBinding> errorBindings = bindingIndex.getResponseBindings(error, Location.PAYLOAD);
                 validateBindings(model, errorBindings).ifPresent(events::add);
             }

smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/protocols/QueryErrorCodeValidator.java

@@ -48,9 +48,9 @@ public List<ValidationEvent> validate(Model model) {
 
     private List<ValidationEvent> validateService(Model model, ServiceShape service) {
         TopDownIndex index = TopDownIndex.of(model);
-        Set<ShapeId> errors = new HashSet<>(service.getErrors());
+        Set<ShapeId> errors = new HashSet<>(service.getErrorsSet());
         for (OperationShape operation : index.getContainedOperations(service)) {
-            errors.addAll(operation.getErrors());
+            errors.addAll(operation.getErrorsSet());
         }
 
         Map<String, Set<String>> errorCodeBindings = new HashMap<>();

smithy-diff/src/main/java/software/amazon/smithy/diff/evaluators/AddedOperationError.java

@@ -29,14 +29,14 @@ public List<ValidationEvent> evaluate(Differences differences) {
     }
 
     private List<ValidationEvent> createErrorViolations(ChangedShape<OperationShape> change, Model newModel) {
-        if (change.getOldShape().getErrors().equals(change.getNewShape().getErrors())) {
+        if (change.getOldShape().getErrorsSet().equals(change.getNewShape().getErrorsSet())) {
             return Collections.emptyList();
         }
 
         List<ValidationEvent> events = new ArrayList<>();
-        for (ShapeId error : change.getNewShape().getErrors()) {
+        for (ShapeId error : change.getNewShape().getErrorsSet()) {
             SourceLocation errorSource = newModel.expectShape(error).getSourceLocation();
-            if (!change.getOldShape().getErrors().contains(error)) {
+            if (!change.getOldShape().getErrorsSet().contains(error)) {
                 events.add(
                         ValidationEvent.builder()
                                 .id(getEventId() + "." + error.getName())

smithy-diff/src/main/java/software/amazon/smithy/diff/evaluators/AddedServiceError.java

@@ -26,13 +26,13 @@ public List<ValidationEvent> evaluate(Differences differences) {
     }
 
     private List<ValidationEvent> createErrorViolations(ChangedShape<ServiceShape> change) {
-        if (change.getOldShape().getErrors().equals(change.getNewShape().getErrors())) {
+        if (change.getOldShape().getErrorsSet().equals(change.getNewShape().getErrorsSet())) {
             return Collections.emptyList();
         }
 
         List<ValidationEvent> events = new ArrayList<>();
-        for (ShapeId id : change.getNewShape().getErrors()) {
-            if (!change.getOldShape().getErrors().contains(id)) {
+        for (ShapeId id : change.getNewShape().getErrorsSet()) {
+            if (!change.getOldShape().getErrorsSet().contains(id)) {
                 events.add(warning(change.getNewShape(),
                         String.format(
                                 "The `%s` error was added to the `%s` service, making this error common "

smithy-diff/src/main/java/software/amazon/smithy/diff/evaluators/RemovedOperationError.java

@@ -27,13 +27,13 @@ public List<ValidationEvent> evaluate(Differences differences) {
     }
 
     private List<ValidationEvent> createErrorViolations(ChangedShape<OperationShape> change) {
-        if (change.getOldShape().getErrors().equals(change.getNewShape().getErrors())) {
+        if (change.getOldShape().getErrorsSet().equals(change.getNewShape().getErrorsSet())) {
             return Collections.emptyList();
         }
 
         List<ValidationEvent> events = new ArrayList<>();
-        for (ShapeId error : change.getOldShape().getErrors()) {
-            if (!change.getNewShape().getErrors().contains(error)) {
+        for (ShapeId error : change.getOldShape().getErrorsSet()) {
+            if (!change.getNewShape().getErrorsSet().contains(error)) {
                 events.add(
                         ValidationEvent.builder()
                                 .id(getEventId() + "." + error.getName())

smithy-diff/src/main/java/software/amazon/smithy/diff/evaluators/RemovedServiceError.java

@@ -26,13 +26,13 @@ public List<ValidationEvent> evaluate(Differences differences) {
     }
 
     private List<ValidationEvent> createErrorViolations(ChangedShape<ServiceShape> change) {
-        if (change.getOldShape().getErrors().equals(change.getNewShape().getErrors())) {
+        if (change.getOldShape().getErrorsSet().equals(change.getNewShape().getErrorsSet())) {
             return Collections.emptyList();
         }
 
         List<ValidationEvent> events = new ArrayList<>();
-        for (ShapeId id : change.getOldShape().getErrors()) {
-            if (!change.getNewShape().getErrors().contains(id)) {
+        for (ShapeId id : change.getOldShape().getErrorsSet()) {
+            if (!change.getNewShape().getErrorsSet().contains(id)) {
                 events.add(warning(change.getNewShape(),
                         String.format(
                                 "The `%s` error was removed from the `%s` service. This means that it "

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

@@ -5,6 +5,7 @@
 package software.amazon.smithy.model.knowledge;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -55,15 +56,15 @@ public OperationIndex(Model model) {
                 outputs.put(operation.getId(), shape);
                 boundOutputOperations.computeIfAbsent(shape.getId(), id -> new HashSet<>()).add(operation);
             });
-            addErrorsFromShape(model, operation.getId(), operation.getErrors());
+            addErrorsFromShape(model, operation.getId(), operation.getErrorsSet());
         }
 
         for (ServiceShape service : model.getServiceShapes()) {
-            addErrorsFromShape(model, service.getId(), service.getErrors());
+            addErrorsFromShape(model, service.getId(), service.getErrorsSet());
         }
     }
 
-    private void addErrorsFromShape(Model model, ShapeId source, List<ShapeId> errorShapeIds) {
+    private void addErrorsFromShape(Model model, ShapeId source, Collection<ShapeId> errorShapeIds) {
         List<StructureShape> errorShapes = new ArrayList<>(errorShapeIds.size());
         Shape sourceShape = model.expectShape(source);
         for (ShapeId target : errorShapeIds) {

smithy-model/src/main/java/software/amazon/smithy/model/neighbor/NeighborVisitor.java

@@ -68,7 +68,7 @@ private List<Relationship> initializeRelationships(Shape shape, int knownMemberC
 
     @Override
     public List<Relationship> serviceShape(ServiceShape shape) {
-        int neededSize = shape.getOperations().size() + shape.getResources().size() + shape.getErrors().size();
+        int neededSize = shape.getOperations().size() + shape.getResources().size() + shape.getErrorsSet().size();
         List<Relationship> result = initializeRelationships(shape, neededSize);
 
         for (ShapeId operation : shape.getOperations()) {
@@ -79,7 +79,7 @@ public List<Relationship> serviceShape(ServiceShape shape) {
             push(result, shape, RelationshipType.RESOURCE, resource);
         }
 
-        for (ShapeId errorId : shape.getErrors()) {
+        for (ShapeId errorId : shape.getErrorsSet()) {
             push(result, shape, RelationshipType.ERROR, errorId);
         }
 
@@ -120,7 +120,7 @@ public List<Relationship> operationShape(OperationShape shape) {
         ShapeId output = shape.getOutput().orElse(null);
 
         // Calculate the number of relationships up front.
-        int assumedRelationshipCount = shape.getErrors().size()
+        int assumedRelationshipCount = shape.getErrorsSet().size()
                 + (input == null ? 0 : 1)
                 + (output == null ? 0 : 1);
         List<Relationship> result = initializeRelationships(shape, assumedRelationshipCount);
@@ -133,7 +133,7 @@ public List<Relationship> operationShape(OperationShape shape) {
             push(result, shape, RelationshipType.OUTPUT, output);
         }
 
-        for (ShapeId errorId : shape.getErrors()) {
+        for (ShapeId errorId : shape.getErrorsSet()) {
             push(result, shape, RelationshipType.ERROR, errorId);
         }
 

smithy-model/src/main/java/software/amazon/smithy/model/shapes/ModelSerializer.java

@@ -346,7 +346,7 @@ public Node operationShape(OperationShape shape) {
                     createTypedBuilder(shape)
                             .withMember("input", serializeReference(shape.getInputShape()))
                             .withMember("output", serializeReference(shape.getOutputShape()))
-                            .withOptionalMember("errors", createOptionalIdList(shape.getIntroducedErrors())))
+                            .withOptionalMember("errors", createOptionalIdList(shape.getIntroducedErrorsSet())))
                     .build();
         }
 
@@ -394,7 +394,7 @@ public Node serviceShape(ServiceShape shape) {
 
             serviceBuilder.withOptionalMember("operations", createOptionalIdList(shape.getIntroducedOperations()));
             serviceBuilder.withOptionalMember("resources", createOptionalIdList(shape.getIntroducedResources()));
-            serviceBuilder.withOptionalMember("errors", createOptionalIdList(shape.getIntroducedErrors()));
+            serviceBuilder.withOptionalMember("errors", createOptionalIdList(shape.getIntroducedErrorsSet()));
 
             if (!shape.getIntroducedRename().isEmpty()) {
                 ObjectNode.Builder renameBuilder = Node.objectNodeBuilder();

smithy-model/src/main/java/software/amazon/smithy/model/shapes/OperationShape.java

@@ -17,6 +17,7 @@
 import software.amazon.smithy.model.traits.MixinTrait;
 import software.amazon.smithy.model.traits.UnitTypeTrait;
 import software.amazon.smithy.utils.BuilderRef;
+import software.amazon.smithy.utils.ListUtils;
 import software.amazon.smithy.utils.ToSmithyBuilder;
 
 /**
@@ -25,8 +26,8 @@
 public final class OperationShape extends Shape implements ToSmithyBuilder<OperationShape> {
     private final ShapeId input;
     private final ShapeId output;
-    private final List<ShapeId> errors;
-    private final List<ShapeId> introducedErrors;
+    private final Set<ShapeId> errors;
+    private final Set<ShapeId> introducedErrors;
 
     private OperationShape(Builder builder) {
         super(builder, false);
@@ -43,11 +44,11 @@ private OperationShape(Builder builder) {
             // here.
             Set<ShapeId> computedErrors = new LinkedHashSet<>();
             for (Shape shape : builder.getMixins().values()) {
-                shape.asOperationShape().ifPresent(mixin -> computedErrors.addAll(mixin.getErrors()));
+                shape.asOperationShape().ifPresent(mixin -> computedErrors.addAll(mixin.getErrorsSet()));
             }
             introducedErrors = builder.errors.copy();
             computedErrors.addAll(introducedErrors);
-            errors = Collections.unmodifiableList(new ArrayList<>(computedErrors));
+            errors = Collections.unmodifiableSet(new LinkedHashSet<>(computedErrors));
         }
 
         if (hasTrait(MixinTrait.ID) && (!input.equals(UnitTypeTrait.UNIT) || !output.equals(UnitTypeTrait.UNIT))) {
@@ -68,7 +69,7 @@ public Builder toBuilder() {
         return updateBuilder(builder())
                 .input(input)
                 .output(output)
-                .errors(getIntroducedErrors());
+                .errors(getIntroducedErrorsSet());
     }
 
     @Override
@@ -134,8 +135,13 @@ public ShapeId getOutputShape() {
         return output;
     }
 
+    @Deprecated
+    public List<ShapeId> getErrors() {
+        return ListUtils.copyOf(errors);
+    }
+
     /**
-     * <p>Gets a list of the error shape IDs bound directly to the operation
+     * <p>Gets a set of the error shape IDs bound directly to the operation
      * that can be encountered.
      *
      * <p>This DOES NOT include errors that are common to a service. Operations
@@ -152,17 +158,22 @@ public ShapeId getOutputShape() {
      * @see #getErrors(ServiceShape)
      * @see OperationIndex#getErrors(ToShapeId, ToShapeId)
      */
-    public List<ShapeId> getErrors() {
+    public Set<ShapeId> getErrorsSet() {
         return errors;
     }
 
+    @Deprecated
+    public List<ShapeId> getIntroducedErrors() {
+        return ListUtils.copyOf(introducedErrors);
+    }
+
     /**
      * Gets the errors introduced by the shape and not inherited
      * from mixins.
      *
      * @return Returns the introduced errors.
      */
-    public List<ShapeId> getIntroducedErrors() {
+    public Set<ShapeId> getIntroducedErrorsSet() {
         return introducedErrors;
     }
 
@@ -177,8 +188,8 @@ public List<ShapeId> getIntroducedErrors() {
      * @see OperationIndex#getErrors(ToShapeId, ToShapeId)
      */
     public List<ShapeId> getErrors(ServiceShape service) {
-        Set<ShapeId> result = new LinkedHashSet<>(service.getErrors());
-        result.addAll(getErrors());
+        Set<ShapeId> result = new LinkedHashSet<>(service.getErrorsSet());
+        result.addAll(getErrorsSet());
         return new ArrayList<>(result);
     }
 
@@ -200,7 +211,7 @@ public boolean equals(Object other) {
     public static final class Builder extends AbstractShapeBuilder<Builder, OperationShape> {
         private ShapeId input = UnitTypeTrait.UNIT;
         private ShapeId output = UnitTypeTrait.UNIT;
-        private final BuilderRef<List<ShapeId>> errors = BuilderRef.forList();
+        private final BuilderRef<Set<ShapeId>> errors = BuilderRef.forOrderedSet();
 
         @Override
         public ShapeType getShapeType() {
@@ -307,7 +318,7 @@ public Builder flattenMixins() {
 
             Set<ShapeId> computedErrors = new LinkedHashSet<>();
             for (Shape shape : getMixins().values()) {
-                shape.asOperationShape().ifPresent(mixin -> computedErrors.addAll(mixin.getErrors()));
+                shape.asOperationShape().ifPresent(mixin -> computedErrors.addAll(mixin.getErrorsSet()));
             }
 
             computedErrors.addAll(errors.peek());