allow returning 3.1 schema types in 'getType'

modules/swagger-core/src/main/java/io/swagger/v3/core/util/DeserializationModule31.java

@@ -1,6 +1,11 @@
 package io.swagger.v3.core.util;
 
+import com.fasterxml.jackson.databind.BeanDescription;
+import com.fasterxml.jackson.databind.DeserializationConfig;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.deser.BeanDeserializerModifier;
 import com.fasterxml.jackson.databind.module.SimpleModule;
+import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Paths;
 import io.swagger.v3.oas.models.callbacks.Callback;
 import io.swagger.v3.oas.models.headers.Header;
@@ -26,5 +31,15 @@ public DeserializationModule31() {
         this.addDeserializer(ApiResponses.class, new ApiResponses31Deserializer());
         this.addDeserializer(Paths.class, new Paths31Deserializer());
         this.addDeserializer(Callback.class, new Callback31Deserializer());
+
+        this.setDeserializerModifier(new BeanDeserializerModifier()
+        {
+            @Override public JsonDeserializer<?> modifyDeserializer(DeserializationConfig config, BeanDescription beanDesc, JsonDeserializer<?> deserializer) {
+                if (beanDesc.getBeanClass() == OpenAPI.class) {
+                    return new OpenAPI31Deserializer(deserializer);
+                }
+                return deserializer;
+            }
+        });
     }
 }

modules/swagger-core/src/main/java/io/swagger/v3/core/util/OpenAPI31Deserializer.java

@@ -0,0 +1,36 @@
+package io.swagger.v3.core.util;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.deser.ResolvableDeserializer;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import io.swagger.v3.oas.models.OpenAPI;
+import io.swagger.v3.oas.models.SpecVersion;
+
+import java.io.IOException;
+
+public class OpenAPI31Deserializer extends StdDeserializer<OpenAPI> implements ResolvableDeserializer {
+
+    private final JsonDeserializer<?> defaultDeserializer;
+
+    public OpenAPI31Deserializer(JsonDeserializer<?> defaultDeserializer)
+    {
+        super(OpenAPI.class);
+        this.defaultDeserializer = defaultDeserializer;
+    }
+
+    @Override
+    public OpenAPI deserialize(JsonParser jp, DeserializationContext ctxt)
+            throws IOException, JsonProcessingException {
+        OpenAPI openAPI = (OpenAPI) defaultDeserializer.deserialize(jp, ctxt);
+        openAPI.setSpecVersion(SpecVersion.V31);
+        return openAPI;
+    }
+    @Override public void resolve(DeserializationContext ctxt) throws JsonMappingException {
+        ((ResolvableDeserializer) defaultDeserializer).resolve(ctxt);
+    }
+}
+

modules/swagger-models/src/main/java/io/swagger/v3/oas/models/media/Schema.java

@@ -1,6 +1,7 @@
 package io.swagger.v3.oas.models.media;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.sun.org.apache.xpath.internal.operations.Bool;
 import io.swagger.v3.oas.models.annotations.OpenAPI30;
 import io.swagger.v3.oas.models.annotations.OpenAPI31;
 import io.swagger.v3.oas.models.Components;
@@ -26,6 +27,8 @@
 
 public class Schema<T> {
 
+    public static final String BIND_TYPE_AND_TYPES = "bind-type";
+
     protected T _default;
 
     private String name;
@@ -1110,6 +1113,10 @@ public Schema addRequiredItem(String requiredItem) {
      **/
 
     public String getType() {
+        boolean bindTypes = Boolean.valueOf(System.getProperty(BIND_TYPE_AND_TYPES, "false"));
+        if (bindTypes && type == null && types != null && types.size() == 1) {
+            return types.iterator().next();
+        }
         return type;
     }