Allow examples for service level errors

smithy-model/src/main/java/software/amazon/smithy/model/validation/validators/ExamplesTraitValidator.java

@@ -18,10 +18,14 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
+import java.util.Set;
 import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.knowledge.TopDownIndex;
 import software.amazon.smithy.model.node.ObjectNode;
 import software.amazon.smithy.model.shapes.OperationShape;
+import software.amazon.smithy.model.shapes.ServiceShape;
 import software.amazon.smithy.model.shapes.Shape;
+import software.amazon.smithy.model.shapes.ShapeId;
 import software.amazon.smithy.model.traits.ExamplesTrait;
 import software.amazon.smithy.model.validation.AbstractValidator;
 import software.amazon.smithy.model.validation.NodeValidationVisitor;
@@ -75,7 +79,11 @@ private List<ValidationEvent> validateExamples(Model model, OperationShape shape
             } else if (isErrorDefined) {
                 ExamplesTrait.ErrorExample errorExample = example.getError().get();
                 Optional<Shape> errorShape = model.getShape(errorExample.getShapeId());
-                if (errorShape.isPresent() && shape.getErrors().contains(errorExample.getShapeId())) {
+                if (errorShape.isPresent() && (
+                        // The error is directly bound to the operation.
+                        shape.getErrors().contains(errorExample.getShapeId())
+                        // The error is bound to all services that contain the operation.
+                        || servicesContainError(model, shape, errorExample.getShapeId()))) {
                     NodeValidationVisitor validator = createVisitor(
                             "error", errorExample.getContent(), model, shape, example);
                     events.addAll(errorShape.get().accept(validator));
@@ -90,6 +98,30 @@ private List<ValidationEvent> validateExamples(Model model, OperationShape shape
         return events;
     }
 
+    private boolean servicesContainError(Model model, OperationShape shape, ShapeId errorId) {
+        TopDownIndex topDownIndex = TopDownIndex.of(model);
+
+        Set<ServiceShape> services = model.getServiceShapes();
+        if (services.isEmpty()) {
+            return false;
+        }
+
+        for (ServiceShape service : services) {
+            // Skip if the service doesn't have the operation.
+            if (!topDownIndex.getContainedOperations(service).contains(shape)) {
+                continue;
+            }
+
+            // We've already checked if the operation contains the error,
+            // so a service having no errors means we've failed.
+            if (service.getErrors().isEmpty() || !service.getErrors().contains(errorId)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
     private NodeValidationVisitor createVisitor(
             String name,
             ObjectNode value,

smithy-model/src/test/resources/software/amazon/smithy/model/errorfiles/validators/examples-trait-service-errors.errors

@@ -0,0 +1,3 @@
+[ERROR] ns.foo#WithError: Error parameters provided for operation without the `ns.foo#ServiceError` error: `Testing 2` | ExamplesTrait
+[ERROR] ns.foo#WithoutError: Error parameters provided for operation without the `ns.foo#OperationError` error: `Testing 3` | ExamplesTrait
+[ERROR] ns.foo#WithoutError: Error parameters provided for operation without the `ns.foo#ServiceError` error: `Testing 4` | ExamplesTrait

smithy-model/src/test/resources/software/amazon/smithy/model/errorfiles/validators/examples-trait-service-errors.smithy

@@ -0,0 +1,109 @@
+$version: "2"
+
+namespace ns.foo
+
+service ErrorBound {
+    version: "2020-07-02"
+    operations: [
+        WithError
+        WithoutError
+    ]
+    errors: [ServiceError]
+}
+
+service ErrorBound2 {
+    version: "2020-07-02"
+    operations: [
+        WithoutError2
+    ]
+    errors: [ServiceError2]
+}
+
+service NoError {
+    version: "2020-07-02"
+    operations: [
+        WithError
+        WithoutError
+    ]
+}
+
+@examples([
+    {
+        "title": "Testing 1",
+        "error": {
+            "shapeId": "ns.foo#OperationError"
+            "content": {
+                "foo": "baz"
+            }
+        }
+    }
+    {
+        "title": "Testing 2"
+        "error": {
+            "shapeId": "ns.foo#ServiceError"
+            "content": {
+                "foo": "baz"
+            }
+        }
+    }
+])
+operation WithError {
+    input := {}
+    errors: [OperationError]
+}
+
+@examples([
+    {
+        "title": "Testing 3",
+        "error": {
+            "shapeId": "ns.foo#OperationError"
+            "content": {
+                "foo": "baz"
+            }
+        }
+    }
+    {
+        "title": "Testing 4"
+        "error": {
+            "shapeId": "ns.foo#ServiceError"
+            "content": {
+                "foo": "baz"
+            }
+        }
+    }
+])
+operation WithoutError {
+    input := {}
+    output := {}
+}
+
+@examples([
+    {
+        "title": "Testing 5"
+        "error": {
+            "shapeId": "ns.foo#ServiceError2"
+            "content": {
+                "foo": "baz"
+            }
+        }
+    }
+])
+operation WithoutError2 {
+    input := {}
+    output := {}
+}
+
+@error("client")
+structure ServiceError {
+    foo: String
+}
+
+@error("client")
+structure ServiceError2 {
+    foo: String
+}
+
+@error("client")
+structure OperationError {
+    foo: String
+}