fix(codegen): strip names from enums (#1837)

* Update checkstyle copyright header to allow 2020/1

* Add integration to strip names from enums

This adds an integration to strip names from enums that GA'd without
them in order to preserve backwards compatibility.

Author: JordonPhillips

codegen/config/checkstyle/checkstyle.xml

@@ -30,9 +30,9 @@
     </module>
 
     <!-- Files must contain a copyright header. -->
-    <module name="Header">
+    <module name="RegexpHeader">
         <property name="header"
-                  value="/*\n * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.\n"/>
+                  value="/\*\n \* Copyright 20(19|20|21) Amazon\.com, Inc\. or its affiliates\. All Rights Reserved\.\n"/>
         <property name="fileExtensions" value="java"/>
     </module>
 

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/StripNewEnumNames.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2020 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.typescript.codegen;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.stream.Collectors;
+import software.amazon.smithy.build.PluginContext;
+import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.node.Node;
+import software.amazon.smithy.model.shapes.Shape;
+import software.amazon.smithy.model.shapes.ShapeId;
+import software.amazon.smithy.model.shapes.StringShape;
+import software.amazon.smithy.model.traits.EnumDefinition;
+import software.amazon.smithy.model.traits.EnumTrait;
+import software.amazon.smithy.model.traits.Trait;
+import software.amazon.smithy.model.transform.ModelTransformer;
+import software.amazon.smithy.typescript.codegen.TypeScriptSettings;
+import software.amazon.smithy.typescript.codegen.integration.TypeScriptIntegration;
+import software.amazon.smithy.utils.IoUtils;
+
+/**
+ * Strips enum names from enums that GA'd without them.
+ *
+ * A number of enums had names back-filled after GA. Since the type generated would change,
+ * this is backwards-incompatible. This integration ensures that clients generated
+ * preserve backwards-compatibility by stripping names from enums that were known to have
+ * launched without them.
+ */
+public final class StripNewEnumNames implements TypeScriptIntegration {
+    private final Set<ShapeId> enumsToStrip;
+
+    public StripNewEnumNames() {
+        // Load the list of enums
+        Node json = Node.parse(IoUtils.readUtf8Url(getClass().getResource("enums-to-strip.json")));
+        Set<ShapeId> toStrip = new HashSet<>();
+        json.asArrayNode().ifPresent(array -> array.forEach(node -> {
+            node.asStringNode().ifPresent(stringNode -> {
+                toStrip.add(ShapeId.from(stringNode.getValue()));
+            });
+        }));
+        enumsToStrip = Collections.unmodifiableSet(toStrip);
+    }
+
+    @Override
+    public Model preprocessModel(PluginContext context, TypeScriptSettings settings) {
+        Model model = context.getModel();
+        Set<Shape> shapesToUpdate = model.shapes(StringShape.class)
+                .filter(shape -> enumsToStrip.contains(shape.getId()))
+                .flatMap(shape -> Trait.flatMapStream(shape, EnumTrait.class))
+                // Replace the existing enum trait with an updated version
+                .map(pair -> pair.getKey().toBuilder().addTrait(stripNames(pair.getValue())).build())
+                .collect(Collectors.toSet());
+        return ModelTransformer.create().replaceShapes(model, shapesToUpdate);
+    }
+
+    private EnumTrait stripNames(EnumTrait trait) {
+        // Use toBuilder to ensure that any other information (e.g. source location) is preserved.
+        EnumTrait.Builder builder = trait.toBuilder().clearEnums();
+        for (EnumDefinition definition : trait.getValues()) {
+            // Setting the name to null effectively removes it
+            builder.addEnum(definition.toBuilder().name(null).build());
+        }
+        return builder.build();
+    }
+}

codegen/smithy-aws-typescript-codegen/src/main/resources/META-INF/services/software.amazon.smithy.typescript.codegen.integration.TypeScriptIntegration

@@ -14,3 +14,4 @@ software.amazon.smithy.aws.typescript.codegen.AddHttp2Dependency
 software.amazon.smithy.aws.typescript.codegen.AddTranscribeStreamingDependency
 software.amazon.smithy.aws.typescript.codegen.AddUserAgentDependency
 software.amazon.smithy.aws.typescript.codegen.AddOmitRetryHeadersDependency
+software.amazon.smithy.aws.typescript.codegen.StripNewEnumNames