[C# - aspnetcore] 'pattern' specification generated code regular expression is wrong

[grmcdorman]

Description

For a parameter specification similar to the following:

{
 "name": "ID",
  "in": "path",
  "description": "ID",
  "required": true,
  "type": "string",
  "pattern": "[0-9a-f]{8}"
}

the resulting action has a parameter decorated (correctly) with [FromRoute][Required]; however, the RegularExpression is incorrect:

[RegularExpression("/[0-9a-f]{8}/")]

The leading and trailing slashes are treated literally, i.e. they must (incorrectly) appear in the parameter value.

openapi-generator version

main; I do not know if this is a regression.

OpenAPI declaration file content or url

{
 "name": "ID",
  "in": "path",
  "description": "ID",
  "required": true,
  "type": "string",
  "pattern": "[0-9a-f]{8}"
}

Command line used for generation

java -jar "openapi-generator-cli.jar" generate -i $GenApiPath -g aspnetcore -o $CodeDirectory -c $Parameters

Steps to reproduce

Generate with the above parameter specification.

Related issues/PRs

Suggest a fix/enhancement

[wing328]

@grmcdorman thanks for reporting the issue. I've filed #1371 to fix the issue and my test result looks good without the forward slashes:

         [Route("/v2/pet/{petId}")]
         [ValidateModelState]
         [SwaggerOperation("UpdatePetWithForm")]
-        public virtual IActionResult UpdatePetWithForm([FromRoute][Required]long? petId, [FromForm]string name, [FromForm]string status)
+        public virtual IActionResult UpdatePetWithForm([FromRoute][Required]long? petId, [FromForm][RegularExpression("[0-9a-f]{8}")]string name, [FromForm]string status)
         {
             //TODO: Uncomment the next line to return response 405 or use other options such as return this.NotFound(), return this.BadRequest(..), ...

[grmcdorman]

Nice; thanks. Good that there's an appropriate override, sign of a good design.

[wing328]

@grmcdorman thanks for the quick review. The fix has been merged into master.