Fixes for JSON merge patch in polymorphic types

javagen/src/main/java/com/azure/autorest/implementation/ClientModelPropertiesManager.java

@@ -95,6 +95,7 @@ public ClientModelPropertiesManager(ClientModel model, JavaSettings settings) {
 
         Map<String, ClientModelPropertyWithMetadata> flattenedProperties = new LinkedHashMap<>();
         boolean hasRequiredProperties = false;
+        boolean hasConstructorArguments = false;
         superConstructorProperties = new LinkedHashMap<>();
         superRequiredProperties = new LinkedHashMap<>();
         superSetterProperties = new LinkedHashMap<>();
@@ -140,6 +141,7 @@ public ClientModelPropertiesManager(ClientModel model, JavaSettings settings) {
                 superPropertyConsumer(property, superRequiredProperties, superConstructorProperties,
                     superReadOnlyProperties, superSetterProperties, settings);
                 hasRequiredProperties |= property.isRequired();
+                hasConstructorArguments |= ClientModelUtil.includePropertyInConstructor(property, settings);
             }
 
             if (property.getNeedsFlatten()) {
@@ -181,6 +183,7 @@ public ClientModelPropertiesManager(ClientModel model, JavaSettings settings) {
                 if (!property.isConstant()) {
                     if (ClientModelUtil.includePropertyInConstructor(property, settings)) {
                         constructorProperties.put(property.getSerializedName(), property);
+                        hasConstructorArguments = true;
                     } else {
                         readOnlyProperties.put(property.getSerializedName(), property);
                     }
@@ -227,16 +230,11 @@ public ClientModelPropertiesManager(ClientModel model, JavaSettings settings) {
             }
         }
 
-        boolean requiredConstructorProperties = hasRequiredProperties && settings.isRequiredFieldsAsConstructorArgs();
-        boolean readOnlyConstructorProperties = settings.isRequiredFieldsAsConstructorArgs()
-            && settings.isIncludeReadOnlyInConstructorArgs()
-            && (!CoreUtils.isNullOrEmpty(readOnlyProperties) || !CoreUtils.isNullOrEmpty(superReadOnlyProperties));
-
         this.hasRequiredProperties = hasRequiredProperties;
         this.requiredPropertiesCount = requiredProperties.size() + superRequiredProperties.size();
         this.setterPropertiesCount = setterProperties.size() + superSetterProperties.size();
         this.readOnlyPropertiesCount = readOnlyProperties.size() + superReadOnlyProperties.size();
-        this.hasConstructorArguments = requiredConstructorProperties || readOnlyConstructorProperties;
+        this.hasConstructorArguments = hasConstructorArguments;
         this.hasXmlElements = hasXmlElements;
         this.hasXmlTexts = hasXmlTexts;
         this.discriminatorProperty = discriminatorProperty;

javagen/src/main/java/com/azure/autorest/model/clientmodel/ClientModel.java

@@ -19,52 +19,64 @@ public class ClientModel {
      * The package that this model class belongs to.
      */
     private final String packageName;
+
     /**
      * Get the name of this model.
      */
     private final String name;
 
     private final String fullName;
+
     /**
      * Get the imports for this model.
      */
     private final List<String> imports;
+
     /**
      * Get the description of this model.
      */
     private final String description;
+
     /**
      * Get whether this model is part of a polymorphic hierarchy.
      */
     private final boolean isPolymorphic;
+
     /**
      * Get whether this model is a parent in a polymorphic hierarchy.
      */
     private final boolean isPolymorphicParent;
+
     /**
      * Get the property that determines which polymorphic model type to create.
      */
     private final ClientModelProperty polymorphicDiscriminator;
+
     /**
      * Get the name of the property that determines which polymorphic model type to create.
      */
     private final String polymorphicDiscriminatorName;
+
     /**
      * Get the name that is used for this model when it is serialized.
      */
     private final String serializedName;
+
     /**
      * Get whether this model needs serialization flattening.
      */
     private final boolean needsFlatten;
+
     /**
      * Get the parent model of this model.
      */
     private final String parentModelName;
+
     /**
      * Get the models that derive from this model.
      */
     private final List<ClientModel> derivedModels;
+
     /**
      * Get the name that will be used for this model's XML element representation.
      */

javagen/src/main/java/com/azure/autorest/model/clientmodel/ClientModelProperty.java

@@ -11,7 +11,7 @@
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Set;
 
@@ -301,7 +301,7 @@ public final void addImportsTo(Set<String> imports, boolean shouldGenerateXmlSer
             imports.add(JsonIgnore.class.getName());
             imports.add(JsonAnySetter.class.getName());
             imports.add(JsonAnyGetter.class.getName());
-            imports.add(HashMap.class.getName());
+            imports.add(LinkedHashMap.class.getName());
         }
 
         if (settings.getClientFlattenAnnotationTarget() == JavaSettings.ClientFlattenAnnotationTarget.FIELD && needsFlatten) {

javagen/src/main/java/com/azure/autorest/model/clientmodel/ClientModelPropertyReference.java

@@ -24,10 +24,8 @@ public class ClientModelPropertyReference implements ClientModelPropertyAccess {
     private final ClientModel targetModel;
     private final ClientModelProperty targetProperty;
 
-    private ClientModelPropertyReference(ClientModelProperty targetProperty,
-                                         ClientModel targetModel,
-                                         ClientModelPropertyAccess referenceProperty,
-                                         String name) {
+    private ClientModelPropertyReference(ClientModelProperty targetProperty, ClientModel targetModel,
+        ClientModelPropertyAccess referenceProperty, String name) {
         this.targetProperty = targetProperty;
         this.targetModel = targetModel;
         this.referenceProperty = referenceProperty;
@@ -46,16 +44,12 @@ public static ClientModelPropertyReference ofParentProperty(ClientModelPropertyR
     }
 
     public static ClientModelPropertyReference ofFlattenProperty(ClientModelProperty targetProperty,
-                                                                 ClientModel targetModel,
-                                                                 ClientModelProperty property,
-                                                                 String name) {
+        ClientModel targetModel, ClientModelProperty property, String name) {
         return new ClientModelPropertyReference(targetProperty, targetModel, property, name);
     }
 
     public static ClientModelPropertyReference ofFlattenProperty(ClientModelProperty targetProperty,
-                                                                 ClientModel targetModel,
-                                                                 ClientModelPropertyReference referenceProperty,
-                                                                 String name) {
+        ClientModel targetModel, ClientModelPropertyReference referenceProperty, String name) {
         if (!referenceProperty.isFromFlattenedProperty()) {
             throw new IllegalArgumentException("Property is not from flattened model: " + referenceProperty.getName());
         }
@@ -88,7 +82,8 @@ public List<ClientModelProperty> getAllProperties() {
         } else if (referenceProperty instanceof ClientModelPropertyReference) {
             properties.addAll(((ClientModelPropertyReference) referenceProperty).getAllProperties());
         } else {
-            throw new IllegalStateException("Unknown subclass of ClientModelPropertyAccess: " + referenceProperty.getClass().getName());
+            throw new IllegalStateException(
+                "Unknown subclass of ClientModelPropertyAccess: " + referenceProperty.getClass().getName());
         }
         return properties;
     }
@@ -109,7 +104,8 @@ public String getDescription() {
 
     @Override
     public String getGetterName() {
-        return CodeNamer.getModelNamer().modelPropertyGetterName(this.referenceProperty.getClientType(), this.getName());
+        return CodeNamer.getModelNamer()
+            .modelPropertyGetterName(this.referenceProperty.getClientType(), this.getName());
     }
 
     @Override
@@ -149,7 +145,8 @@ public boolean isRequired() {
 
     @Override
     public boolean isRequiredForCreate() {
-        return (targetProperty == null || targetProperty.isRequiredForCreate()) && referenceProperty.isRequiredForCreate();
+        return (targetProperty == null || targetProperty.isRequiredForCreate())
+            && referenceProperty.isRequiredForCreate();
     }
 
     @Override

javagen/src/main/java/com/azure/autorest/model/javamodel/JavaClass.java

@@ -73,6 +73,22 @@ public final void protectedMemberVariable(String variableType, String variableNa
         addNewLine = true;
     }
 
+    /**
+     * Adds a variable with the given declaration and visibility.
+     * <p>
+     * This doesn't support modifiers. If you need to add modifiers, use
+     * {@link #variable(String, JavaVisibility, JavaModifier...)}. This will just be a non-final, non-static variable
+     * with the given visibility.
+     *
+     * @param variableDeclaration The variable declaration.
+     * @param visibility The visibility of the variable.
+     */
+    public final void variable(String variableDeclaration, JavaVisibility visibility) {
+        addExpectedNewLine();
+        contents.line(visibility + " " + variableDeclaration + ";");
+        addNewLine = true;
+    }
+
     /**
      * Adds a variable with the given declaration, visibility, and modifiers.
      * <p>

javagen/src/main/java/com/azure/autorest/template/ConvenienceMethodTemplateBase.java

@@ -784,11 +784,13 @@ private static List<MethodParameter> getParameters(ClientMethod method, boolean
      * @return the name of the variable that holds the converted parameter
      */
     private static String writeParameterConversionExpressionWithJsonMergePatchEnabled(JavaBlock javaBlock, String convenientParameterTypeName, String convenientParameterName, String expression) {
-            String variableName = convenientParameterName + "InBinaryData";
-            javaBlock.line(String.format("JsonMergePatchHelper.get%1$sAccessor().prepareModelForJsonMergePatch(%2$s, true);", convenientParameterTypeName, convenientParameterName));
-            javaBlock.line(String.format("BinaryData %1$s = BinaryData.fromBytes(%2$s.toBytes());", variableName, expression)); // BinaryData.fromObject() will not fire serialization, use toBytes() to fire serialization
-            javaBlock.line(String.format("JsonMergePatchHelper.get%1$sAccessor().prepareModelForJsonMergePatch(%2$s, false);", convenientParameterTypeName, convenientParameterName));
-            return variableName;
+        String variableName = convenientParameterName + "InBinaryData";
+        javaBlock.line(String.format("JsonMergePatchHelper.get%1$sAccessor().prepareModelForJsonMergePatch(%2$s, true);", convenientParameterTypeName, convenientParameterName));
+        javaBlock.line("BinaryData " + variableName + " = " + expression + ";");
+        javaBlock.line("// BinaryData.fromObject() will not fire serialization, use getLength() to fire serialization.");
+        javaBlock.line(variableName + ".getLength();");
+        javaBlock.line(String.format("JsonMergePatchHelper.get%1$sAccessor().prepareModelForJsonMergePatch(%2$s, false);", convenientParameterTypeName, convenientParameterName));
+        return variableName;
     }
 
     protected static class MethodParameter {