fix: Handle arrays of enum strings correctly

[daniel-kullmann]

Without this change an array of enums will result in e.g.:

export type Model1 = {
values: 'A' | 'B' | 'C'[];
} & Record<string, any>;

which means the value can be either "A", "B", or "C"[], which is wrong.

[cla-assistant]

All committers have signed the CLA.

[daniel-kullmann]

I tested this with the following API json:

{
  "openapi": "3.0.3",
  "info": {
    "version": "1.0.0",
    "title": "Api",
    "description": "API"
  },
  "components": {
    "schemas": {
      "Model1": {
        "type": "object",
        "required": ["values"],
        "properties": {
          "values": {
            "type": "array",
            "items": {
              "type": "string",
              "uniqueItems": true,
              "minItems": 0,
              "enum": [
                "A",
                "B",
                "C"
              ]
            }
          }
        }
      }
    }
  },
  "paths": {
    "/values": {
      "get": {
        "summary": "",
        "operationId": "getValues",
        "responses": {
          "200": {
            "description": "A list of all values",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Model1"
                }
              }
            }
          }
        }
      }
    }
  }
}

[ZhongpinWang]

Hi @daniel-kullmann ,

Thanks for your contribution! We really appreciate it.

One thing is confusing me a bit. In your json object, I see uniqueItems is set to true. Then it should go into Set<${type} instead?

Overall seems like a valid fix. @deekshas8 WDYT?

[daniel-kullmann]

Hi @ZhongpinWang I agree, but for some reason, the value of uniqueItems is not present in the code that I changed. Maybe that is another bug?

Regardless of that, if uniqueItemsis false, the generated code should still be correct. I agree that this might be an edge case (non-unique list of enums), but it can happen.

[daniel-kullmann]

I have created a repo to reproduce the problem: https://github.com/daniel-kullmann/openapi-generator-bug

[daniel-kullmann]

Ah, uniqueItemsshould be one level higher, next to type: "array"

      "Model1": {
        "type": "object",
        "required": ["values"],
        "properties": {
          "values": {
            "type": "array",
            "uniqueItems": true,
            "items": {
              "type": "string",
              "minItems": 0,
              "enum": [
                "A",
                "B",
                "C"
              ]
            }
          }
        }
      }