Migration of contracts instantiated with WasmMsg::Instantiate fail

[spareshwar]

When a CW contract is instantiated from command-line, the migratable flag can be set to true. However, when the contract is instantiated programmatically using WasmMsg::Instantiate, there isn't a way to set migratable flag, so migration of such contracts fail.

[ethanfrey]

This is a good point and oversight when I added WasmMsg::Migrate.

I would propose adding admin: Option<String> to WasmMsg::Instantiate. The contract could set admin: Some(env.contract.address) and then be able to migrate the sub-contract

[webmaster128]

Do we have an example for deserializing the JSON of Option<String> to a Go struct? The JSON schema is this:

{
  "admin": {
    "type": [
      "string",
      "null"
    ]
  }
}

[ethanfrey]

Try for yourself: https://play.golang.org/p/W-VB5AXQNFN

{"admin":""} and {"admin":null} and {"admin":""} all unmarshal to the empty string. Play around there to try other cases

[webmaster128]

Good, thanks. *string is a good mirror type that wrks both ways as it is serialized to null or a string.