Set additionalProperties false for CFN objects

This commit adds a CfnMapper that defaults the `additionalProperties`
property to `false` for named entries in a schema's `definitions` that
are of the `object` type. This is recommended behavior by CloudFormation
and, if not present, results in a warning when developing a resource.

smithy-aws-cloudformation/src/main/java/software/amazon/smithy/aws/cloudformation/schema/fromsmithy/mappers/AdditionalPropertiesMapper.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.smithy.aws.cloudformation.schema.fromsmithy.mappers;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Optional;
+import software.amazon.smithy.aws.cloudformation.schema.fromsmithy.CfnMapper;
+import software.amazon.smithy.aws.cloudformation.schema.fromsmithy.Context;
+import software.amazon.smithy.aws.cloudformation.schema.model.ResourceSchema;
+import software.amazon.smithy.model.node.Node;
+import software.amazon.smithy.model.node.ObjectNode;
+import software.amazon.smithy.model.node.StringNode;
+
+/**
+ * CloudFormation issues a warning in its build tooling every time it detects
+ * an "object" type in the converted JSON Schema's definitions that doesn't set
+ * "additionalProperties" to "false". This mapper sets that to reduce the
+ * warnings customers receive when developing resources from automatically
+ * generated resource schemas.
+ *
+ * @see <a href="https://github.com/aws-cloudformation/cloudformation-cli/blob/8491ac54d12028a7e00295b39f102e3786e52ccf/src/rpdk/core/data_loaders.py#L286-L295">Warning in CFN CLI</a>
+ */
+final class AdditionalPropertiesMapper implements CfnMapper {
+
+    @Override
+    public byte getOrder() {
+        // This is a desired behavior from CFN, so set it near the end
+        // while still having room for other overrides if necessary.
+        return 124;
+    }
+
+    @Override
+    public ObjectNode updateNode(Context context, ResourceSchema resourceSchema, ObjectNode node) {
+        Optional<ObjectNode> definitionsOptional = node.getObjectMember("definitions");
+
+        // This replaces every entry in the "definitions" map and uses a
+        // LinkedHashMap so that order is maintained, as entries will have
+        // been sorted before we get to this mapper.
+        Map<StringNode, Node> updatedNodes = new LinkedHashMap<>();
+        if (definitionsOptional.isPresent()) {
+            for (Map.Entry<StringNode, Node> entry : definitionsOptional.get().getMembers().entrySet()) {
+                ObjectNode valueNode = entry.getValue().expectObjectNode();
+
+                if (valueNode.expectStringMember("type").getValue().equals("object")) {
+                    valueNode = valueNode.withMember("additionalProperties", false);
+                }
+
+                updatedNodes.put(entry.getKey(), valueNode);
+            }
+            node = node.withMember("definitions", Node.objectNode(updatedNodes));
+        }
+        return node;
+    }
+}

smithy-aws-cloudformation/src/main/java/software/amazon/smithy/aws/cloudformation/schema/fromsmithy/mappers/CoreExtension.java

@@ -27,6 +27,7 @@ public final class CoreExtension implements Smithy2CfnExtension {
     @Override
     public List<CfnMapper> getCfnMappers() {
         return ListUtils.of(
+                new AdditionalPropertiesMapper(),
                 new DeprecatedMapper(),
                 new DocumentationMapper(),
                 new IdentifierMapper(),

smithy-aws-cloudformation/src/test/java/software/amazon/smithy/aws/cloudformation/schema/fromsmithy/mappers/AdditionalPropertiesMapperTest.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.smithy.aws.cloudformation.schema.fromsmithy.mappers;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+
+import org.junit.jupiter.api.Test;
+import software.amazon.smithy.aws.cloudformation.schema.CfnConfig;
+import software.amazon.smithy.aws.cloudformation.schema.fromsmithy.CfnConverter;
+import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.node.ObjectNode;
+import software.amazon.smithy.model.shapes.ShapeId;
+
+public class AdditionalPropertiesMapperTest {
+    @Test
+    public void setsAdditionalPropertiesFalse() {
+        Model model = Model.assembler()
+                .addImport(JsonAddTest.class.getResource("simple.smithy"))
+                .discoverModels()
+                .assemble()
+                .unwrap();
+
+        CfnConfig config = new CfnConfig();
+        config.setOrganizationName("Smithy");
+        config.setService(ShapeId.from("smithy.example#TestService"));
+
+        ObjectNode resourceNode = CfnConverter.create()
+                .config(config)
+                .convertToNodes(model)
+                .get("Smithy::TestService::FooResource");
+
+        assertFalse(resourceNode.expectObjectMember("definitions")
+                .expectObjectMember("ComplexProperty")
+                .expectBooleanMember("additionalProperties")
+                .getValue());
+    }
+
+}

smithy-aws-cloudformation/src/test/resources/software/amazon/smithy/aws/cloudformation/schema/fromsmithy/disable-caps-fooresource.cfn.json

@@ -11,15 +11,17 @@
         "property": {
           "type": "string"
         }
-      }
+      },
+      "additionalProperties": false
     },
     "FooMap": {
       "type": "object",
       "patternProperties": {
         ".+": {
           "type": "string"
         }
-      }
+      },
+      "additionalProperties": false
     }
   },
   "properties": {

smithy-aws-cloudformation/src/test/resources/software/amazon/smithy/aws/cloudformation/schema/fromsmithy/integ/complex-resource.cfn.json

@@ -8,15 +8,17 @@
         ".+": {
           "type": "string"
         }
-      }
+      },
+      "additionalProperties": false
     },
     "ComplexProperty": {
       "type": "object",
       "properties": {
         "AnotherProperty": {
           "type": "string"
         }
-      }
+      },
+      "additionalProperties": false
     }
   },
   "properties": {

smithy-aws-cloudformation/src/test/resources/software/amazon/smithy/aws/cloudformation/schema/fromsmithy/integ/queue-example.cfn.json

@@ -11,15 +11,17 @@
         "DeadLetterTargetArn": {
           "type": "string"
         }
-      }
+      },
+      "additionalProperties": false
     },
     "TagMap": {
       "type": "object",
       "patternProperties": {
         ".+": {
           "type": "string"
         }
-      }
+      },
+      "additionalProperties": false
     }
   },
   "properties": {

smithy-aws-cloudformation/src/test/resources/software/amazon/smithy/aws/cloudformation/schema/fromsmithy/simple-service-aws.cfn.json

@@ -13,7 +13,8 @@
         "Another": {
           "type": "string"
         }
-      }
+      },
+      "additionalProperties": false
     }
   },
   "properties": {

smithy-aws-cloudformation/src/test/resources/software/amazon/smithy/aws/cloudformation/schema/fromsmithy/smithy-testservice-fooresource.cfn.json

@@ -11,15 +11,17 @@
         "Another": {
           "type": "string"
         }
-      }
+      },
+      "additionalProperties": false
     },
     "FooMap": {
       "type": "object",
       "patternProperties": {
         ".+": {
           "type": "string"
         }
-      }
+      },
+      "additionalProperties": false
     }
   },
   "properties": {