The `DefaultValue` of a `CustomProperty` is incorrect type

[stevehipwell]

Since GitHub added support for multi-select it's been possible for the DefaultValue of a CustomProperty to be either a string or an array of strings; see schema below.

      "default_value": {
        "oneOf": [
          {
            "type": "string"
          },
          {
            "type": "array",
            "items": {
              "type": "string"
            }
          }
        ],
        "description": "Default value of the property",
        "type": [
          "null",
          "string",
          "array"
        ]
      },

Based on the existing implementation of CustomPropertyValue where Value has the same type we should modify DefaultValue to any.

[gmlewis]

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Thank you!

[gmlewis]

@zyfy29 - please make a note in issues when you decide to work on them so that others will not attempt to work on it at the same time as you. Thank you!

[zyfy29]

OK, I will do so the next time.

[stevehipwell]

I don't think switching the default value to any is the right API design here. The GitHub type system isn't well aligned to Go, but there are alternatives to falling back to any. My suggestion would be to add a DefaultValues: []string struct field and use conditional marshalling (as I used for rulests) to set the correct field depending on the property type.

It's worth noting that this pattern is a non-breaking API change.

[gmlewis]

My only concern with attempting to strongly-type the DefaultValue field here is that GitHub may expand the set of what is allowable over time.

You originally wrote in the description above:

Based on the existing implementation of CustomPropertyValue where Value has the same type we should modify DefaultValue to any.

and I'm now confused if I'm misunderstanding your proposal or if you changed your mind. Could you please clarify, @stevehipwell ?