[core] Initial FeatureSet structures

modules/openapi-generator-core/src/main/java/org/openapitools/codegen/meta/GeneratorMetadata.java

@@ -16,16 +16,29 @@
 
 package org.openapitools.codegen.meta;
 
+import org.openapitools.codegen.meta.features.*;
+
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  * Represents metadata about a generator.
  */
+@SuppressWarnings("WeakerAccess")
 public class GeneratorMetadata {
     private Stability stability;
+    private Map<String, FeatureSet> libraryFeatures;
+    private FeatureSet featureSet;
     private String generationMessage;
 
     private GeneratorMetadata(Builder builder) {
-        stability = builder.stability;
-        generationMessage = builder.generationMessage;
+        if (builder != null) {
+            stability = builder.stability;
+            generationMessage = builder.generationMessage;
+            libraryFeatures = builder.libraryFeatures;
+            featureSet = builder.featureSet;
+        }
     }
 
     /**
@@ -37,18 +50,13 @@ public static Builder newBuilder() {
         return new Builder();
     }
 
-    /**
-     * Creates a new builder object for {@link GeneratorMetadata}, accepting another instance from which to copy properties.
-     *
-     * @param copy An existing instance to copy defaults from
-     *
-     * @return A new builder instance, with values preset to those of 'copy'.
-     */
     public static Builder newBuilder(GeneratorMetadata copy) {
         Builder builder = new Builder();
         if (copy != null) {
             builder.stability = copy.getStability();
             builder.generationMessage = copy.getGenerationMessage();
+            builder.libraryFeatures = copy.getLibraryFeatures();
+            builder.featureSet = copy.getFeatureSet();
         }
         return builder;
     }
@@ -71,12 +79,32 @@ public Stability getStability() {
         return stability;
     }
 
+    /**
+     * Returns the feature set supported by the generator.
+     *
+     * @return The set of available features.
+     */
+    public FeatureSet getFeatureSet() {
+        return featureSet;
+    }
+
+    /**
+     * Returns the list of features supported by generator libraries.
+     *
+     * @return A map of library name to feature set for that library.
+     */
+    public Map<String, FeatureSet> getLibraryFeatures() {
+        return libraryFeatures;
+    }
+
     /**
      * {@code GeneratorMetadata} builder static inner class.
      */
     public static final class Builder {
         private Stability stability;
         private String generationMessage;
+        private FeatureSet featureSet = FeatureSet.UNSPECIFIED;
+        private Map<String, FeatureSet> libraryFeatures = new HashMap<>();
 
         private Builder() {
         }
@@ -92,6 +120,32 @@ public Builder stability(Stability stability) {
             return this;
         }
 
+        /**
+         * Sets the {@code featureSet} and returns a reference to this Builder so that the methods can be chained together.
+         *
+         * @param featureSet the {@code featureSet} to set
+         * @return a reference to this Builder
+         */
+        public Builder featureSet(FeatureSet featureSet) {
+            if (featureSet != null) {
+                this.featureSet = featureSet;
+            } else {
+                this.featureSet = FeatureSet.UNSPECIFIED;
+            }
+            return this;
+        }
+
+        /**
+         * Sets the {@code libraryFeatures} and returns a reference to this Builder so that the methods can be chained together.
+         *
+         * @param libraryFeatures the {@code libraryFeatures} to set
+         * @return a reference to this Builder
+         */
+        public Builder libraryFeatures(Map<String, FeatureSet> libraryFeatures) {
+            this.libraryFeatures = libraryFeatures;
+            return this;
+        }
+
         /**
          * Sets the {@code generationMessage} and returns a reference to this Builder so that the methods can be chained together.
          *

modules/openapi-generator-core/src/main/java/org/openapitools/codegen/meta/features/ClientModificationFeature.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2019 OpenAPI-Generator Contributors (https://openapi-generator.tech)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License 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 org.openapitools.codegen.meta.features;
+
+import org.openapitools.codegen.meta.features.annotations.ToolingExtension;
+
+/**
+ * Defines a general set of modifications supported by a generated client.
+ */
+public enum ClientModificationFeature {
+    /**
+     * Supports defining a custom overall base path in generated client output.
+     */
+    @ToolingExtension
+    BasePath,
+
+    /**
+     * Supports customizing authorizations in generated client output.
+     */
+    @ToolingExtension
+    Authorizations,
+
+    /**
+     * Supports customizing the user agent in generated client output.
+     */
+    @ToolingExtension
+    UserAgent
+}