Add nullable support to C# client (refactor)

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java

@@ -75,6 +75,12 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
     protected Set<String> collectionTypes;
     protected Set<String> mapTypes;
 
+    // true if support nullable type
+    protected boolean supportNullable = Boolean.FALSE;
+
+    // nullable type
+    protected Set<String> nullableType = new HashSet<String>();
+
     private static final Logger LOGGER = LoggerFactory.getLogger(AbstractCSharpCodegen.class);
 
     public AbstractCSharpCodegen() {
@@ -130,19 +136,26 @@ public AbstractCSharpCodegen() {
                         "String",
                         "string",
                         "bool?",
+                        "bool",
                         "double?",
+                        "double",
                         "decimal?",
+                        "decimal",
                         "int?",
+                        "int",
                         "long?",
+                        "long",
                         "float?",
+                        "float",
                         "byte[]",
                         "ICollection",
                         "Collection",
                         "List",
                         "Dictionary",
                         "DateTime?",
+                        "DateTime",
                         "DateTimeOffset?",
-                        "String",
+                        "DataTimeOffset",
                         "Boolean",
                         "Double",
                         "Int32",
@@ -157,6 +170,7 @@ public AbstractCSharpCodegen() {
         instantiationTypes.put("list", "List");
         instantiationTypes.put("map", "Dictionary");
 
+
         // Nullable types here assume C# 2 support is not part of base
         typeMapping = new HashMap<String, String>();
         typeMapping.put("string", "string");
@@ -176,6 +190,11 @@ public AbstractCSharpCodegen() {
         typeMapping.put("map", "Dictionary");
         typeMapping.put("object", "Object");
         typeMapping.put("UUID", "Guid?");
+
+        // nullable type
+        nullableType = new HashSet<String>(
+                Arrays.asList("decimal", "bool", "int", "float", "long", "double", "DateTime", "Guid")
+        );
     }
 
     public void setReturnICollection(boolean returnICollection) {
@@ -209,8 +228,7 @@ public void useDateTimeOffset(boolean flag) {
         this.useDateTimeOffsetFlag = flag;
         if (flag) {
             typeMapping.put("DateTime", "DateTimeOffset?");
-        }
-        else {
+        } else {
             typeMapping.put("DateTime", "DateTime?");
         }
     }
@@ -421,8 +439,8 @@ private void postProcessEnumRefs(final Map<String, Object> models) {
         }
 
         for (Map.Entry<String, Object> entry : models.entrySet()) {
-            String swaggerName = entry.getKey();
-            CodegenModel model = ModelUtils.getModelByName(swaggerName, models);
+            String openAPIName = entry.getKey();
+            CodegenModel model = ModelUtils.getModelByName(openAPIName, models);
             if (model != null) {
                 for (CodegenProperty var : model.allVars) {
                     if (enumRefs.containsKey(var.dataType)) {
@@ -483,7 +501,7 @@ private void postProcessEnumRefs(final Map<String, Object> models) {
                     }
                 }
             } else {
-                LOGGER.warn("Expected to retrieve model %s by name, but no model was found. Check your -Dmodels inclusions.", swaggerName);
+                LOGGER.warn("Expected to retrieve model %s by name, but no model was found. Check your -Dmodels inclusions.", openAPIName);
             }
         }
     }
@@ -573,28 +591,30 @@ public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> o
                         }
                     }
 
-                    for (CodegenParameter parameter: operation.allParams) {
-                        CodegenModel model = null;
-                        for(Object modelHashMap: allModels) {
-                            CodegenModel codegenModel = ((HashMap<String, CodegenModel>) modelHashMap).get("model");
-                            if (codegenModel.getClassname().equals(parameter.dataType)) {
-                                model = codegenModel;
-                                break;
+                    if (!isSupportNullable()) {
+                        for (CodegenParameter parameter : operation.allParams) {
+                            CodegenModel model = null;
+                            for (Object modelHashMap : allModels) {
+                                CodegenModel codegenModel = ((HashMap<String, CodegenModel>) modelHashMap).get("model");
+                                if (codegenModel.getClassname().equals(parameter.dataType)) {
+                                    model = codegenModel;
+                                    break;
+                                }
                             }
-                        }
 
-                        if (model == null) {
-                            // Primitive data types all come already marked
-                            parameter.isNullable = true;
-                        } else {
-                            // Effectively mark enum models as enums and non-nullable
-                            if (model.isEnum) {
-                                parameter.isEnum = true;
-                                parameter.allowableValues = model.allowableValues;
-                                parameter.isPrimitiveType = true;
-                                parameter.isNullable = false;
-                            } else {
+                            if (model == null) {
+                                // Primitive data types all come already marked
                                 parameter.isNullable = true;
+                            } else {
+                                // Effectively mark enum models as enums and non-nullable
+                                if (model.isEnum) {
+                                    parameter.isEnum = true;
+                                    parameter.allowableValues = model.allowableValues;
+                                    parameter.isPrimitiveType = true;
+                                    parameter.isNullable = false;
+                                } else {
+                                    parameter.isNullable = true;
+                                }
                             }
                         }
                     }
@@ -792,6 +812,14 @@ protected boolean isReservedWord(String word) {
         return reservedWords.contains(word);
     }
 
+    public String getNullableType(Schema p, String type) {
+        if (languageSpecificPrimitives.contains(type)) {
+            return type;
+        } else {
+            return null;
+        }
+    }
+
     @Override
     public String getSchemaType(Schema p) {
         String openAPIType = super.getSchemaType(p);
@@ -804,8 +832,9 @@ public String getSchemaType(Schema p) {
 
         if (typeMapping.containsKey(openAPIType)) {
             type = typeMapping.get(openAPIType);
-            if (languageSpecificPrimitives.contains(type)) {
-                return type;
+            String languageType = getNullableType(p, type);
+            if (languageType != null) {
+                return languageType;
             }
         } else {
             type = openAPIType;
@@ -950,6 +979,14 @@ public void setInterfacePrefix(final String interfacePrefix) {
         this.interfacePrefix = interfacePrefix;
     }
 
+    public boolean isSupportNullable() {
+        return supportNullable;
+    }
+
+    public void setSupportNullable(final boolean supportNullable) {
+        this.supportNullable = supportNullable;
+    }
+
     @Override
     public String toEnumValue(String value, String datatype) {
         // C# only supports enums as literals for int, int?, long, long?, byte, and byte?. All else must be treated as strings.
@@ -1011,7 +1048,9 @@ public String escapeUnsafeCharacters(String input) {
     @Override
     public boolean isDataTypeString(String dataType) {
         // also treat double/decimal/float as "string" in enum so that the values (e.g. 2.8) get double-quoted
-        return "String".equalsIgnoreCase(dataType) || "double?".equals(dataType) || "decimal?".equals(dataType) || "float?".equals(dataType);
+        return "String".equalsIgnoreCase(dataType) ||
+                "double?".equals(dataType) || "decimal?".equals(dataType) || "float?".equals(dataType) ||
+                "double".equals(dataType) || "decimal".equals(dataType) || "float".equals(dataType);
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java

@@ -776,7 +776,6 @@ public String getNameUsingModelPropertyNaming(String name) {
         }
     }
 
-
     public void setPackageName(String packageName) {
         this.packageName = packageName;
     }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpRefactorClientCodegen.java

@@ -22,6 +22,7 @@
 import com.google.common.collect.ImmutableMap;
 import com.samskivert.mustache.Mustache;
 
+import io.swagger.v3.oas.models.media.ArraySchema;
 import io.swagger.v3.oas.models.media.Schema;
 
 import org.openapitools.codegen.CliOption;
@@ -32,6 +33,7 @@
 import org.openapitools.codegen.CodegenProperty;
 import org.openapitools.codegen.CodegenType;
 import org.openapitools.codegen.SupportingFile;
+import org.openapitools.codegen.utils.ModelUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -84,19 +86,39 @@ public class CSharpRefactorClientCodegen extends AbstractCSharpCodegen {
     // By default, generated code is considered public
     protected boolean nonPublicApi = Boolean.FALSE;
 
+
     public CSharpRefactorClientCodegen() {
         super();
+
+        // mapped non-nullable type without ?
+        typeMapping = new HashMap<String, String>();
+        typeMapping.put("string", "string");
+        typeMapping.put("binary", "byte[]");
+        typeMapping.put("ByteArray", "byte[]");
+        typeMapping.put("boolean", "bool");
+        typeMapping.put("integer", "int");
+        typeMapping.put("float", "float");
+        typeMapping.put("long", "long");
+        typeMapping.put("double", "double");
+        typeMapping.put("number", "decimal");
+        typeMapping.put("DateTime", "DateTime");
+        typeMapping.put("date", "DateTime");
+        typeMapping.put("file", "System.IO.Stream");
+        typeMapping.put("array", "List");
+        typeMapping.put("list", "List");
+        typeMapping.put("map", "Dictionary");
+        typeMapping.put("object", "Object");
+        typeMapping.put("UUID", "Guid");
+
+        setSupportNullable(Boolean.TRUE);
+        hideGenerationTimestamp = Boolean.TRUE;
         supportsInheritance = true;
         modelTemplateFiles.put("model.mustache", ".cs");
         apiTemplateFiles.put("api.mustache", ".cs");
-
         modelDocTemplateFiles.put("model_doc.mustache", ".md");
         apiDocTemplateFiles.put("api_doc.mustache", ".md");
-
         embeddedTemplateDir = templateDir = "csharp-refactor";
 
-        hideGenerationTimestamp = Boolean.TRUE;
-
         cliOptions.clear();
 
         // CLI options
@@ -223,7 +245,6 @@ public void processOpts() {
             setModelPropertyNaming((String) additionalProperties.get(CodegenConstants.MODEL_PROPERTY_NAMING));
         }
 
-
         if (isEmpty(apiPackage)) {
             setApiPackage("Api");
         }
@@ -609,6 +630,10 @@ public void setPackageGuid(String packageGuid) {
     public void postProcessParameter(CodegenParameter parameter) {
         postProcessPattern(parameter.pattern, parameter.vendorExtensions);
         super.postProcessParameter(parameter);
+
+        if (!parameter.required && nullableType.contains(parameter.dataType)) { //optional
+            parameter.dataType = parameter.dataType + "?";
+        }
     }
 
     @Override
@@ -852,4 +877,17 @@ public Mustache.Compiler processCompiler(Mustache.Compiler compiler) {
         // To avoid unexpected behaviors when options are passed programmatically such as { "supportsAsync": "" }
         return super.processCompiler(compiler).emptyStringIsFalse(true);
     }
+
+    @Override
+    public String getNullableType(Schema p, String type) {
+        if (languageSpecificPrimitives.contains(type)) {
+            if (isSupportNullable() && ModelUtils.isNullable(p) && nullableType.contains(type)) {
+                return type + "?";
+            } else {
+                return type;
+            }
+        } else {
+            return null;
+        }
+    }
 }

modules/openapi-generator/src/main/resources/csharp-refactor/api.mustache

@@ -85,7 +85,7 @@ namespace {{packageName}}.{{apiPackage}}
     /// </summary>
     {{>visibility}} interface {{interfacePrefix}}{{classname}} : {{interfacePrefix}}{{classname}}Sync{{#supportsAsync}}, {{interfacePrefix}}{{classname}}Async{{/supportsAsync}}
     {
-        
+
     }
 
     /// <summary>
@@ -94,7 +94,7 @@ namespace {{packageName}}.{{apiPackage}}
     {{>visibility}} partial class {{classname}} : {{interfacePrefix}}{{classname}}
     {
         private {{packageName}}.Client.ExceptionFactory _exceptionFactory = (name, response) => null;
-        
+
         /// <summary>
         /// Initializes a new instance of the <see cref="{{classname}}"/> class.
         /// </summary>
@@ -151,7 +151,7 @@ namespace {{packageName}}.{{apiPackage}}
             if(asyncClient == null) throw new ArgumentNullException("asyncClient");
             {{/supportsAsync}}
             if(configuration == null) throw new ArgumentNullException("configuration");
-            
+
             this.Client = client;
             {{#supportsAsync}}
             this.AsynchronousClient = asyncClient;
@@ -225,13 +225,15 @@ namespace {{packageName}}.{{apiPackage}}
         public {{packageName}}.Client.ApiResponse<{{#returnType}} {{{returnType}}} {{/returnType}}{{^returnType}}Object{{/returnType}}> {{operationId}}WithHttpInfo ({{#allParams}}{{{dataType}}} {{paramName}}{{^required}}{{#optionalMethodArgument}} = null{{/optionalMethodArgument}}{{/required}}{{#hasMore}}, {{/hasMore}}{{/allParams}})
         {
             {{#allParams}}
+            {{^isNullable}}
             {{#required}}
             // verify the required parameter '{{paramName}}' is set
             if ({{paramName}} == null)
                 throw new {{packageName}}.Client.ApiException(400, "Missing required parameter '{{paramName}}' when calling {{classname}}->{{operationId}}");
+
             {{/required}}
+            {{/isNullable}}
             {{/allParams}}
-
             {{packageName}}.Client.RequestOptions requestOptions = new {{packageName}}.Client.RequestOptions();
 
             String[] @contentTypes = new String[] {
@@ -362,11 +364,14 @@ namespace {{packageName}}.{{apiPackage}}
         public async System.Threading.Tasks.Task<{{packageName}}.Client.ApiResponse<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Object{{/returnType}}>> {{operationId}}AsyncWithHttpInfo ({{#allParams}}{{{dataType}}} {{paramName}}{{^required}}{{#optionalMethodArgument}} = null{{/optionalMethodArgument}}{{/required}}{{#hasMore}}, {{/hasMore}}{{/allParams}})
         {
             {{#allParams}}
+            {{^isNullable}}
             {{#required}}
             // verify the required parameter '{{paramName}}' is set
             if ({{paramName}} == null)
                 throw new {{packageName}}.Client.ApiException(400, "Missing required parameter '{{paramName}}' when calling {{classname}}->{{operationId}}");
+
             {{/required}}
+            {{/isNullable}}
             {{/allParams}}
 
             {{packageName}}.Client.RequestOptions requestOptions = new {{packageName}}.Client.RequestOptions();

modules/openapi-generator/src/main/resources/csharp-refactor/modelGeneric.mustache

@@ -58,6 +58,7 @@
             {{#vars}}
             {{^isInherited}}
             {{^isReadOnly}}
+            {{^isNullable}}
             {{#required}}
             {{^isEnum}}
             // to ensure "{{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}}" is required (not null)
@@ -74,6 +75,7 @@
             this.{{name}} = {{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}};
             {{/isEnum}}
             {{/required}}
+            {{/isNullable}}
             {{/isReadOnly}}
             {{/isInherited}}
             {{/vars}}

samples/client/petstore/csharp-refactor/OpenAPIClient/docs/ApiResponse.md

@@ -3,7 +3,7 @@
 
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
-**Code** | **int?** |  | [optional] 
+**Code** | **int** |  | [optional] 
 **Type** | **string** |  | [optional] 
 **Message** | **string** |  | [optional] 
 

samples/client/petstore/csharp-refactor/OpenAPIClient/docs/ArrayOfArrayOfNumberOnly.md

@@ -3,7 +3,7 @@
 
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
-**ArrayArrayNumber** | **List<List<decimal?>>** |  | [optional] 
+**ArrayArrayNumber** | **List<List<decimal>>** |  | [optional] 
 
 [[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)