refs swagger-api/swagger-codegen#10496 - fix null type handling

Author: frantuma

src/main/java/io/swagger/codegen/v3/generators/dotnet/AbstractCSharpCodegen.java

@@ -755,7 +755,7 @@ public String getSchemaType(Schema propertySchema) {
         String type;
 
         if (swaggerType == null) {
-            swaggerType = StringUtils.EMPTY; // set swagger type to empty string if null
+            swaggerType = "object";
         }
 
         // TODO avoid using toLowerCase as typeMapping should be case-sensitive

src/main/java/io/swagger/codegen/v3/generators/typescript/AbstractTypeScriptClientCodegen.java

@@ -307,6 +307,10 @@ public String toDefaultValue(Schema propertySchema) {
     @Override
     public String  getSchemaType(Schema schema) {
         String swaggerType = super.getSchemaType(schema);
+        if (swaggerType == null) {
+            // default to object, see #10496
+            swaggerType = "object";
+        }
         if (schema instanceof ComposedSchema) {
             ComposedSchema composedSchema = (ComposedSchema)schema;
             if (composedSchema.getAllOf() != null && !composedSchema.getAllOf().isEmpty()) {