[BUG] URI encoded $ref not properly decoded

[SimonIT]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

I wanted to generate a dart lib for flutter with the provided swagger yaml config. The problem is, that some of the generated class names contain spaces which are not valid. After writing a fix for it (PR #5693), I used swagger to edit the yaml. Swagger suggests to use %20 instead of normal spaces inside $ref definition links because it's an URI (see docs). Now I got the problem, that some class names contain %20.

openapi-generator version

4.2.3

OpenAPI declaration file content or url

https://raw.githubusercontent.com/wbt-solutions/openproject_dart_sdk/master/openProject_swagger.yaml

Command line used for generation

I used the command java -jar .\openapi-generator-cli-4.2.3.jar generate -g dart -i openProject_swagger.yaml -o openproject_dart_sdk/ inside the Windows Powershell.

Steps to reproduce

Execute the command with the provided config and look for example in the model\work_package.dart.

Related issues/PRs

Haven't found any.

Suggest a fix

Properly decode the $ref attribute as URI.

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[SimonIT]

I don't know, why the bot added the dart label. The problem is for every language, I think. I tried also Java and there is the problem, too.
I would also provide a PR for fixing this problem, but I can't find the code for parsing the open api config. If someone would give me a hint, I will try to fix this.

[bzmw]

Having a similar issue here: PagerDuty/api-schema#82

Was there any resolution that you found @SimonIT

[SimonIT]

I discovered now that if you replace this line

openapi-generator/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java

Line 389 in c9939a2

return ref;

with

        return URLDecoder.decode(ref);

the name gets properly decoded. I will make a PR.
It would be very nice if you can approve my fix

[SimonIT]

Okay, I tested it myself with the provided command from your issue and this didn't fix your problem.
I think your problem is, that #/paths/ is nowhere handled by the generator because IntelliJ couldn't find any occurrences of it in the whole project. I think you have to change you specification or you make a PR which solves this.