Arrays of enums as input

[JacksonDahl2]

I'm encountering a problem when trying to implement an array of an enum as an input on an endpoint. I have seen this discussion post and it almost answers this but not completely.

This input generates the correct openapi spec

     status: z.array(zScanResultCondition).optional()

    GetV2WorkspacesParameterStatus:
      type: array
      items:
        type: string
        enum:
          - COMPLIANT
          - ALL_FIXED
          - SOME_FIXED
          - NONE_FIXED

The issue is that this results in an error as the input comes in as a string from the query parameters instead as a array. The earlier discussion had a solution to this:

z.string()
  .transform( (str) => str.split(",") )
  .pipe(
    z.array(zScanResultCondition)
  )
  .optional()

However this results in the input type being a string instead of the enum values that I would like.

    GetV2WorkspacesParameterStatus:
      type: string

---

I have found a solution to this, but it's not very elegant, it is to just make an enum of the string transform, and my array type:

  status: z.union([
    z.string().transform(str => str.split(',') as z.infer<typeof zPullRequestStatus>[]),
    z.array(zPullRequestStatus)
  ]).optional()

And this works, except that it then has a union type as the input, when I would ideally like it to only be an array, as I'm using this spec to generate types elsewhere:

    GetV2WorkspacesParameterStatus:
      anyOf:
        - type: string
        - type: array
          items:
            type: string
            enum:
              - EXPECTED
              - MERGED
              - CLOSED
              - OPEN

Is there any solution to this issue?

[RobinTail]

The issue is that this results in an error as the input comes in as a string from the query parameters instead as a array.

That's because you're using comma separator, which is not a conventional way to pass arrays via query string, @JacksonDahl2 .
Try this:

?items=COMPLIANT&items=ALL_FIXED

⚠️ this is for Express 5

[JacksonDahl2]

When I do it like that it doesn't recognize items as part of my schema, so if I add .strict() at the end of my schema, the request breaks do to unrecognized keys.

Do I need to do something to my express configuration in order to transform items[] to items[] in order to get zod to recognize it?

[JacksonDahl2]

For anyone in the future, my issue was not query parsing. I just added the qs package to my express app and everything works.

Thanks!

[RobinTail]

That's a little strange because qs is a dependency of express

└─┬ express 5.1.0
  ├─┬ body-parser 2.2.0
  │ └── qs 6.14.0
  └── qs 6.14.0

[RobinTail]

@JacksonDahl2 , it turned out that in Express 5 they changed the default query parser from "extended" (which is qs) to "simple" (which is node:querystring), so brackets no longer work and not needed

[RobinTail]

I'm going to make it configurable in #2922
There is a misleading info in Express documentation saying that qs is the default parser, but in fact it's Node.js native querystring.parse().