Support for Optional enums (#375)

Author: fbenz

spring-auto-restdocs-core/src/main/java/capital/scalable/restdocs/constraints/ConstraintReaderImpl.java

@@ -22,6 +22,7 @@
 import static capital.scalable.restdocs.constraints.ConstraintAndGroupDescriptionResolver.VALUE;
 import static capital.scalable.restdocs.constraints.MethodParameterValidatorConstraintResolver.CONSTRAINT_CLASS;
 import static capital.scalable.restdocs.util.FormatUtil.collectionToString;
+import static capital.scalable.restdocs.util.TypeUtil.firstGenericType;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
@@ -31,6 +32,7 @@
 import static org.springframework.util.ReflectionUtils.findField;
 
 import java.lang.reflect.Field;
+import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -130,11 +132,28 @@ private List<String> getEnumConstraintMessage(Class<?> javaBaseClass, String jav
             return emptyList();
         }
 
-        return getEnumConstraintMessage(field.getType());
+        if (field.getType().isEnum()) {
+            return getEnumConstraintMessage(field.getType());
+        } else {
+            return getEnumConstraintMessage(firstGenericType(field.getGenericType(), javaBaseClass));
+        }
     }
 
     private List<String> getEnumConstraintMessage(MethodParameter param) {
-        return getEnumConstraintMessage(param.getParameterType());
+        if (param.getParameterType().isEnum()) {
+            return getEnumConstraintMessage(param.getParameterType());
+        } else {
+            return getEnumConstraintMessage(firstGenericType(param));
+        }
+    }
+
+    private List<String> getEnumConstraintMessage(Type type) {
+        if (type instanceof Class) {
+            Class<?> clazz = (Class<?>) type;
+            return getEnumConstraintMessage(clazz);
+        } else {
+            return emptyList();
+        }
     }
 
     private List<String> getEnumConstraintMessage(Class<?> rawClass) {

spring-auto-restdocs-core/src/main/java/capital/scalable/restdocs/payload/AbstractJacksonFieldSnippet.java

@@ -88,37 +88,6 @@ protected FieldDescriptors createFieldDescriptors(Operation operation,
         }
     }
 
-    protected Type firstGenericType(MethodParameter param) {
-        Type type = param.getGenericParameterType();
-        if (type instanceof TypeVariable) {
-            TypeVariable tv = (TypeVariable) type;
-            return findTypeFromTypeVariable(tv, param.getContainingClass());
-        } else if (type instanceof ParameterizedType) {
-            ParameterizedType parameterizedType = (ParameterizedType) type;
-            Type actualArgument = parameterizedType.getActualTypeArguments()[0];
-            if (actualArgument instanceof Class) {
-                return actualArgument;
-            } else if (actualArgument instanceof TypeVariable) {
-                TypeVariable typeVariable = (TypeVariable)actualArgument;
-                return findTypeFromTypeVariable(typeVariable, param.getContainingClass());
-            }
-            return ((ParameterizedType) type).getActualTypeArguments()[0];
-        } else {
-            return Object.class;
-        }
-    }
-
-    protected Type findTypeFromTypeVariable(TypeVariable typeVariable, Class<?> clazz) {
-        String variableName = typeVariable.getName();
-        Map<TypeVariable, Type> typeMap = GenericTypeResolver.getTypeVariableMap(clazz);
-        for (TypeVariable tv : typeMap.keySet()) {
-            if (StringUtils.equals(tv.getName(), variableName)) {
-                return typeMap.get(tv);
-            }
-        }
-        return Object.class;
-    }
-
     protected abstract Type getType(HandlerMethod method);
 
     protected abstract boolean shouldFailOnUndocumentedFields();

spring-auto-restdocs-core/src/main/java/capital/scalable/restdocs/payload/JacksonModelAttributeSnippet.java

@@ -43,6 +43,7 @@
 import capital.scalable.restdocs.util.HandlerMethodUtil;
 
 import static capital.scalable.restdocs.SnippetRegistry.AUTO_MODELATTRIBUTE;
+import static capital.scalable.restdocs.util.TypeUtil.firstGenericType;
 
 public class JacksonModelAttributeSnippet extends AbstractJacksonFieldSnippet {
     private final boolean failOnUndocumentedFields;

spring-auto-restdocs-core/src/main/java/capital/scalable/restdocs/payload/JacksonRequestFieldSnippet.java

@@ -20,6 +20,7 @@
 package capital.scalable.restdocs.payload;
 
 import static capital.scalable.restdocs.SnippetRegistry.AUTO_REQUEST_FIELDS;
+import static capital.scalable.restdocs.util.TypeUtil.firstGenericType;
 
 import java.lang.reflect.GenericArrayType;
 import java.lang.reflect.Type;

spring-auto-restdocs-core/src/main/java/capital/scalable/restdocs/payload/JacksonResponseFieldSnippet.java

@@ -20,6 +20,7 @@
 package capital.scalable.restdocs.payload;
 
 import static capital.scalable.restdocs.SnippetRegistry.AUTO_RESPONSE_FIELDS;
+import static capital.scalable.restdocs.util.TypeUtil.firstGenericType;
 
 import java.lang.reflect.GenericArrayType;
 import java.lang.reflect.ParameterizedType;

spring-auto-restdocs-core/src/main/java/capital/scalable/restdocs/util/TypeUtil.java

@@ -27,13 +27,20 @@
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.lang.reflect.TypeVariable;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 
 import capital.scalable.restdocs.jackson.TypeMapping;
 import com.fasterxml.jackson.annotation.JsonSubTypes;
 import com.fasterxml.jackson.databind.JavaType;
 import com.fasterxml.jackson.databind.type.TypeFactory;
+import org.apache.commons.lang3.StringUtils;
+import org.springframework.core.GenericTypeResolver;
+import org.springframework.core.MethodParameter;
 import org.springframework.util.ReflectionUtils;
 
 public class TypeUtil {
@@ -192,4 +199,38 @@ private static List<JavaType> resolveNonArrayTypes(JavaType javaType, TypeFactor
 
         return types;
     }
+
+    public static Type firstGenericType(MethodParameter param) {
+        return firstGenericType(param.getGenericParameterType(), param.getContainingClass());
+    }
+
+    public static Type firstGenericType(Type type, Class<?> containingClass) {
+        if (type instanceof TypeVariable) {
+            TypeVariable tv = (TypeVariable) type;
+            return findTypeFromTypeVariable(tv, containingClass);
+        } else if (type instanceof ParameterizedType) {
+            ParameterizedType parameterizedType = (ParameterizedType) type;
+            Type actualArgument = parameterizedType.getActualTypeArguments()[0];
+            if (actualArgument instanceof Class) {
+                return actualArgument;
+            } else if (actualArgument instanceof TypeVariable) {
+                TypeVariable typeVariable = (TypeVariable)actualArgument;
+                return findTypeFromTypeVariable(typeVariable, containingClass);
+            }
+            return ((ParameterizedType) type).getActualTypeArguments()[0];
+        } else {
+            return Object.class;
+        }
+    }
+
+    public static Type findTypeFromTypeVariable(TypeVariable typeVariable, Class<?> clazz) {
+        String variableName = typeVariable.getName();
+        Map<TypeVariable, Type> typeMap = GenericTypeResolver.getTypeVariableMap(clazz);
+        for (TypeVariable tv : typeMap.keySet()) {
+            if (StringUtils.equals(tv.getName(), variableName)) {
+                return typeMap.get(tv);
+            }
+        }
+        return Object.class;
+    }
 }

spring-auto-restdocs-core/src/test/java/capital/scalable/restdocs/constraints/ConstraintReaderImplTest.java

@@ -39,6 +39,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 import capital.scalable.restdocs.i18n.SnippetTranslationManager;
 import com.fasterxml.jackson.annotation.JsonValue;
@@ -107,6 +108,10 @@ public void getConstraintMessages() {
         messages = reader.getConstraintMessages(Constraintz.class, "enum3");
         assertThat(messages.size(), is(1));
         assertThat(messages.get(0), is("Must be one of [A first, B second]"));
+
+        messages = reader.getConstraintMessages(Constraintz.class, "optionalEnum");
+        assertThat(messages.size(), is(1));
+        assertThat(messages.get(0), is("Must be one of [ONE, TWO]"));
     }
 
     @Test
@@ -153,14 +158,17 @@ public void getOptionalMessages() {
         messages = reader.getOptionalMessages(Constraintz.class, "enum2");
         assertThat(messages.size(), is(1));
         assertThat(messages.get(0), is("false"));
+
+        messages = reader.getOptionalMessages(Constraintz.class, "optionalEnum");
+        assertThat(messages.size(), is(0));
     }
 
     @Test
     public void getParameterConstraintMessages() throws NoSuchMethodException {
         ConstraintReader reader = createWithValidation(new ObjectMapper(), SnippetTranslationManager.getDefaultResolver(), new ResourceBundleConstraintDescriptionResolver());
 
         Method method = MethodTest.class.getMethod("exec", Integer.class, String.class,
-                Enum1.class);
+                Enum1.class, Optional.class);
 
         List<String> messages = reader.getConstraintMessages(new MethodParameter(method, 0));
         assertThat(messages.size(), is(2));
@@ -174,6 +182,10 @@ public void getParameterConstraintMessages() throws NoSuchMethodException {
         messages = reader.getConstraintMessages(new MethodParameter(method, 2));
         assertThat(messages.size(), is(1));
         assertThat(messages.get(0), is("Must be one of [ONE, TWO]"));
+
+        messages = reader.getConstraintMessages(new MethodParameter(method, 3));
+        assertThat(messages.size(), is(1));
+        assertThat(messages.get(0), is("Must be one of [ONE, TWO]"));
     }
 
     @Test
@@ -192,7 +204,7 @@ public void getOptionalMessages_validationNotPresent() {
     public void getParameterConstraintMessages_validationNotPresent() throws NoSuchMethodException {
         ConstraintReaderImpl reader = createWithoutValidation(new ObjectMapper(), SnippetTranslationManager.getDefaultResolver(), new ResourceBundleConstraintDescriptionResolver());
         Method method = MethodTest.class.getMethod("exec", Integer.class, String.class,
-                Enum1.class);
+                Enum1.class, Optional.class);
         assertThat(reader.getConstraintMessages(new MethodParameter(method, 0)).size(), is(0));
     }
 
@@ -303,6 +315,8 @@ static class Constraintz {
         private Enum2 enum2;
 
         private Enum3 enum3;
+
+        private Optional<Enum1> optionalEnum;
     }
 
     enum Enum1 {ONE, TWO}
@@ -335,7 +349,8 @@ public void exec(
                 @Max(value = 2, groups = Update.class) Integer count,
                 @NotBlank
                 @OneOf({ "all", "single" }) String type,
-                Enum1 enumeration) {
+                Enum1 enumeration,
+                Optional<Enum1> optionalEnum) {
         }
     }