From e5868a7596218f013e989bc802b29fb87f9fed90 Mon Sep 17 00:00:00 2001 From: Joelle Mahfoud <252808402+joelle-a-dev@users.noreply.github.com> Date: Tue, 11 Aug 2026 01:01:52 +0300 Subject: [PATCH] fix(csharp): preserve constructor param name when property is renamed to avoid class-name clash When a C# model property collides with its own class name, the codegen renames it with a leading underscore (e.g. error_message -> _ErrorMessage) to avoid a compile error. The generated constructor parameter name was still derived by camelizing that already-renamed value at template render time, which strips the leading underscore and produces a name that no longer matches the property. Newtonsoft.Json then fails to bind the constructor argument to the property during deserialization, leaving it null. Compute the parameter name in lockstep with the property rename instead of re-deriving it from the mutated name at render time. Fixes #12757 --- .../languages/AbstractCSharpCodegen.java | 4 ++++ .../resources/csharp/modelGeneric.mustache | 20 +++++++++---------- 2 files changed, 14 insertions(+), 10 deletions(-) diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/AbstractCSharpCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/AbstractCSharpCodegen.java index 40ee5cf99bb..f892af70c6d 100644 --- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/AbstractCSharpCodegen.java +++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/AbstractCSharpCodegen.java @@ -355,12 +355,16 @@ public Map postProcessModels(Map objs) { Map mo = (Map) _mo; CodegenModel cm = (CodegenModel) mo.get("model"); for (CodegenProperty var : cm.vars) { + String paramName = toParamName(var.name); + // check to see if model name is same as the property name // which will result in compilation error // if found, prepend with _ to workaround the limitation if (var.name.equalsIgnoreCase(cm.name)) { var.name = "_" + var.name; + paramName = "_" + paramName; } + var.vendorExtensions.put("x-parameter-name", paramName); } } // process enum in models diff --git a/modules/swagger-codegen/src/main/resources/csharp/modelGeneric.mustache b/modules/swagger-codegen/src/main/resources/csharp/modelGeneric.mustache index 99e0b090143..b59c743b38f 100644 --- a/modules/swagger-codegen/src/main/resources/csharp/modelGeneric.mustache +++ b/modules/swagger-codegen/src/main/resources/csharp/modelGeneric.mustache @@ -49,26 +49,26 @@ /// {{#vars}} {{^isReadOnly}} - /// {{#description}}{{description}}{{/description}}{{^description}}{{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}}{{/description}}{{#required}} (required){{/required}}{{#defaultValue}} (default to {{defaultValue}}){{/defaultValue}}. + /// {{#description}}{{description}}{{/description}}{{^description}}{{vendorExtensions.x-parameter-name}}{{/description}}{{#required}} (required){{/required}}{{#defaultValue}} (default to {{defaultValue}}){{/defaultValue}}. {{/isReadOnly}} {{/vars}} {{#hasOnlyReadOnly}} [JsonConstructorAttribute] {{/hasOnlyReadOnly}} - public {{classname}}({{#readWriteVars}}{{{datatypeWithEnum}}}{{#isEnum}}{{^isContainer}}{{^required}}?{{/required}}{{/isContainer}}{{/isEnum}} {{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}} = {{#defaultValue}}{{{defaultValue}}}{{/defaultValue}}{{^defaultValue}}default({{{datatypeWithEnum}}}{{#isEnum}}{{^isContainer}}{{^required}}?{{/required}}{{/isContainer}}{{/isEnum}}){{/defaultValue}}{{^-last}}, {{/-last}}{{/readWriteVars}}){{#parent}} : base({{#parentVars}}{{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}}{{#hasMore}}, {{/hasMore}}{{/parentVars}}){{/parent}} + public {{classname}}({{#readWriteVars}}{{{datatypeWithEnum}}}{{#isEnum}}{{^isContainer}}{{^required}}?{{/required}}{{/isContainer}}{{/isEnum}} {{vendorExtensions.x-parameter-name}} = {{#defaultValue}}{{{defaultValue}}}{{/defaultValue}}{{^defaultValue}}default({{{datatypeWithEnum}}}{{#isEnum}}{{^isContainer}}{{^required}}?{{/required}}{{/isContainer}}{{/isEnum}}){{/defaultValue}}{{^-last}}, {{/-last}}{{/readWriteVars}}){{#parent}} : base({{#parentVars}}{{vendorExtensions.x-parameter-name}}{{#hasMore}}, {{/hasMore}}{{/parentVars}}){{/parent}} { {{#vars}} {{^isInherited}} {{^isReadOnly}} {{#required}} - // to ensure "{{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}}" is required (not null) - if ({{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}} == null) + // to ensure "{{vendorExtensions.x-parameter-name}}" is required (not null) + if ({{vendorExtensions.x-parameter-name}} == null) { - throw new InvalidDataException("{{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}} is a required property for {{classname}} and cannot be null"); + throw new InvalidDataException("{{vendorExtensions.x-parameter-name}} is a required property for {{classname}} and cannot be null"); } else { - this.{{name}} = {{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}}; + this.{{name}} = {{vendorExtensions.x-parameter-name}}; } {{/required}} {{/isReadOnly}} @@ -78,18 +78,18 @@ {{^isInherited}} {{^isReadOnly}} {{^required}} - {{#defaultValue}}// use default value if no "{{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}}" provided - if ({{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}} == null) + {{#defaultValue}}// use default value if no "{{vendorExtensions.x-parameter-name}}" provided + if ({{vendorExtensions.x-parameter-name}} == null) { this.{{name}} = {{{defaultValue}}}; } else { - this.{{name}} = {{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}}; + this.{{name}} = {{vendorExtensions.x-parameter-name}}; } {{/defaultValue}} {{^defaultValue}} -this.{{name}} = {{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}}; +this.{{name}} = {{vendorExtensions.x-parameter-name}}; {{/defaultValue}} {{/required}} {{/isReadOnly}}