Enable Unit Testing for Sponsored Transactions in Simnet

[ronoel]

Currently, it is not possible to perform unit testing for sponsored transactions using Simnet in Clarinet. This limitation makes it difficult to test scenarios where transactions are sponsored by another account, requiring manual workarounds outside of the Simnet environment.

To support unit testing for sponsored transactions, I propose adding a sponsorPrivateKey parameter in the constructor of CallFnArgs. This way, when calling callPublicFn with a sponsor key, the transaction will be considered a sponsored transaction.

Current Implementation:

callPublicFn(args: CallFnArgs): TransactionRes;

export class CallFnArgs {
  free(): void;
  constructor(contract: string, method: string, args: (Uint8Array)[], sender: string);
}

Proposed Implementation:

export class CallFnArgs {
  free(): void;
  constructor(contract: string, method: string, args: (Uint8Array)[], sender: string, sponsorPrivateKey: string = null);
}

By including this optional parameter, developers can write unit tests that simulate sponsored transactions directly in Simnet.

Alternatives solution:

• Implementing a separate method to explicitly handle sponsored transactions in the Simnet testing environment.
• Using workarounds like manually crafting and signing sponsored transactions before sending them to Simnet.