Possible API improvement for IdentityInput

[Dhaiwat10]

Take this Sway function signature for example:

fn new_game(player: Identity);

If you try to call this function via the TS SDK, it would look something like this:

// for an `Address`
const wallet = Wallet.generate({});

await contract.functions.new_game({ Address: { value: wallet.address.toB256() });

// for a `Contract`
await contract.functions.new_game({ ContractId: { value: otherContract.id.toB256() });

It works, but this takes 3-4 attempts to get right and involves some mental gymnastics. I was eventually able to find out how to make this work because I have been working on the SDK for more than a year now. Most new users would find this daunting.

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I feel like the API should be simplified to something like:

await contract.functions.new_game({ value: wallet.address }); // `Address`

await contract.functions.new_game({ value: contract.id, type: 'contractId' }); // `ContractId`

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Any comments & ideas welcome!

[petertonysmith94]

💯 Love this!

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Would suggest keeping the ContractId as the type value:

await contract.functions.new_game({ value: contract.id, type: 'ContractId' });

I assume we'll default to an Address type and the explicit form would be valid?

await contract.functions.new_game({ value: contract.address, type: 'Address' });

[arboleya]

I am lacking proper context here, but ideally, this would be:

await contract.functions.new_game(value);

This would feel more intuitive and standard (like other usages) since the Sway parameter is a single value:

fn new_game(player: Identity);

[arboleya]

FYI - new docs are incoming via #1870.

[petertonysmith94]

Does #1870 close this discussion then?

[arboleya]

Not necessarily.

IIUC, that one is only adding docs while this one is considering a possible API change/simplification.

[Dhaiwat10]

@arboleya how would you do that via the ABI? 🤔 The ABI will only be able to tell us the fact that the given function accepts Identity - which can be an Address or ContractId. It is still upto the user to decide what they want to pass in as the input. I'm not following you here

[arboleya]

I see. Things are identical from the ABI's perspective.

I'm just trying to collaborate and cross the idea with previous conversations.

[nedsalk]

Great idea! A solution that'd make the type property obsolete could be the following:

type Identity = {address: string, contractId?: never} | {address?: never; contractId: string}

await contract.functions.new_game({ address: contract.address });
await contract.functions.new_game({ contractId: contract.id });

The Identity type allows only one of the properties to be defined; if somebody tries to assign values to both, it'll give them a compile-time error. I wrote a playground example here.

[danielbate]

+1 for this implementation. We had this forum post where the user had a similar problem. IMO if you know the function takes an enum value it can be deduced from the types, but we can do more and I believe the above does that.

[arboleya]

Thanks, everyone.

I created an issue for it:

• Improve DX for IdentityInput #1891