dfinity / agent-js

A collection of libraries and tools for building software around the Internet Computer, in JavaScript.
https://agent-js.icp.xyz
Apache License 2.0
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feat: call returns raw certificate, if requested #877

Closed seniorjoinu closed 3 months ago

seniorjoinu commented 4 months ago

Description

It is possible to speed up inter-canister calls in some scenarios, if delegate making the call and transferring the response to the user. For example, you've make an ICRC-1 token transfer to some dApp. This dApp, instead of making its own inter-canister call to token's index canister, would ask the user itself to fetch the block from the index and pass the certified response back to one of its own canisters, which can then verify the response.

Such an optimization requires being able to make a call and simultaneously retrieve the raw certificate client-side. This PR adds this feature in a clean non-breaking way.

Also, there was an accidentally discovered bug related to pollForResponse function. It was invoked with blsVerify parameter in place of request parameter. Maybe it did nothing, but it seemed suspicious. This wasn't catched by Typescript, because request parameter is of type any.

Note

  1. The certificate is only returned when CallConfig.returnCertificate is set to true. In that case, instead of just reply the method will return { result: reply, cert: rawCertificate }. If CallConfig.returnCertificate is unset of false - nothing changes, everything works as usual.
  2. The certificate is only returned for update calls. For query calls empty buffer is returned like this { result: reply, cert: emptyBuf }. This is done to: a) comply with method signature change (ActorMethod interface is the same for query and update calls); b) enable replica signature/certificate to be returned the same way for queries in future.
  3. I was not able to run e2e tests - could not find any scripts mentioned in the docs. Also, docs on local development seem outdated. Please, take action.

How Has This Been Tested?

Added a unit-test to actor.test.ts testcase.

seniorjoinu commented 4 months ago

Usage example

// returns the certificate
const { result, cert } = await canister.do_stuff.withOptions({ returnCertificate: true })(args);

// works as usual, if executed without options
const result = await canister.do_stuff();

// works as usual, if `returnCertificate` option is unset
const result1 = await canister.do_stuff.withOptions({ canisterId: cid })(args);

// works as usual, if `returnCertificate` option is `false`
const result3 = await canister.do_stuff.withOptions({ returnCertificate: false })(args);

// typescript will throw an error
const result = await canister.do_stuff.withOptions({ returnCertificate: true })(args);
processResult(result); // <- result is type { result: Result, cert: ArrayBuffer } and not just Result

// typescript will throw an error
const { result, cert } = await canister.do_stuff(); // <- type Result has no fields "cert", "result"
krpeacock commented 4 months ago

I'll need to think a little more about the design of modifying the return signature based on an option. I might want to take a slightly different approach to the API, but I do appreciate the work you've done on this

seniorjoinu commented 4 months ago

@krpeacock

I'll need to think a little more about the design of modifying the return signature based on an option. I might want to take a slightly different approach to the API, but I do appreciate the work you've done on this

We could also do this as a separate method, similar to .withOptions. Something like .andCertificate(). The reason why I didn't do this in the first place is because in that case we would probably need two of those: one regular and one with http details. This would be better for JS without TS setups.

I could implement that very quickly, just say your word. We need that feature for our project asap, so I would do whatever it takes.

Also, what do you think about the fixing part? Was there a bug in pollForResponse or not?

seniorjoinu commented 3 months ago

@krpeacock pinging you once again. Hope it is fine.