swagger-api / swagger-api/swagger-codegen

[JAVASCRIPT] Cannot handle circular schema dependencies

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Description

Description

If you have a schema that references itself the generate code has a bug when running in the browser (i.e. not for node) where the model is referenced before it is defined. So if you call Model.constructFromObject(...) you receive the error:

Cannot read property 'constructFromObject' of undefined
Swagger-codegen version

2.3.1

Swagger declaration file content or url
swagger: "2.0"
info:
  title: Sample API
  version: 1.0.0

definitions:
  Person:
    properties:
      name:
        type: string
      parent:
        $ref: '#/definitions/Person'

paths:
  /person:
    get:
      produces:
        - application/json
      responses:
        200:
          schema:
            $ref: '#/definitions/Person'
Command line used for generation

swagger-codegen generate -o ./client -l javascript -i ./api.yaml

Steps to reproduce
  1. Generate client code using the above yaml file
  2. Add index.html to src/ dir:
<html>
    <script src="./model/Person.js"></script>
    <script>
      window.SampleApi.Person.constructFromObject({ parent: { name : "hat" } })
    </script>
</html>
  1. Browse to this page
  2. See error in console:
Person.js:70 Uncaught TypeError: Cannot read property 'constructFromObject' of undefined
    at Function.exports.constructFromObject (Person.js:70)
    at (index):4
Related issues/PRs

I think this is a duplicate of #6879 but that is not entirely clear from the issue description

Suggest a fix/enhancement

src/models/Person.js looks like this:

    root.SampleApi.Person = factory(root.SampleApi.ApiClient, root.SampleApi.Person);
  }
}(this, function(ApiClient, Person) {
 ...
  exports.constructFromObject = function(data, obj) {
    if (data) {
      obj = obj || new exports();

      if (data.hasOwnProperty('name')) {
        obj['name'] = ApiClient.convertToType(data['name'], 'String');
      }
      if (data.hasOwnProperty('parent')) {
        // ** Person is undefined here **
        obj['parent'] = Person.constructFromObject(data['parent']);
      }
    }
    return obj;
  }
...

So root.SampleApi.Person is passed in as input to its own factory function, it is undefined at this time obviously.

Potential fix:

Pass in a reference to the API object to the factory rather than the specific models:

   // root.SampleApi.Person = factory(root.SampleApi.ApiClient, root.SampleApi.Person);
   root.SampleApi.Person = factory(root.SampleApi); // added
  }
// }(this, function(ApiClient, Person) {
}(this, function(SampleApi) { // added
 ...
  exports.constructFromObject = function(data, obj) {
    var ApiClient = SampleApi.ApiClient // added
    var Person = SampleApi.Person // added
...

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Reproduce the issue with the supplied Swagger YAML and the swagger-codegen generate -l javascript command, then inspect the generated src/models/Person.js factory and compare issue #6879. Trace how circular model references are initialized in the browser, and verify that Person.constructFromObject handles the self-reference without an undefined-model error.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript
Domain
tooling
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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