Using NAJ To Interact With JS SDK Contracts

[BenKurrek]

I’m also having some trouble calling the contract with NAJ. This is what I have so far:

      let contractAccount = "js-10.examples.benjiman.testnet"
      let methodName = "getState"
      let args = ''
      let input = Buffer.concat([Buffer.from(contractAccount), Buffer.from([0]), Buffer.from(methodName), Buffer.from([0]), Buffer.from(args)])
      let encodedArgs = input.toString('base64')

      const status = await contract.call_js_contract({
       encodedArgs
      });

      console.log('status: ', status)

But this doesn’t seem to be working. I’m getting the following error:

Failure [jsvm.testnet]: Error: {"index":0,"kind":{"ExecutionError":"Smart contract panicked: JS contract name is empty"}}

Upon checking the explorer, it looks like my arguments aren’t being passed in properly. See my screenshots below to see the args that are being passed in the explorer:

[BenKurrek]

Answer from @ailisp

From what works in workspaces-js, binary args need to be provided as Uint8Array (Buffer also works) instead of base64 encoded string:

export declare function functionCall(methodName: string, args: Uint8Array | object, gas: BN, deposit: BN, stringify?: typeof stringifyJsonOrBytes): Action;

Modify your code to this should work:

const status = await contract.call_js_contract({
       args: input
      });

reference: Phuong's work on near-cli: https://github.com/near/near-cli/pull/975/files With his impl, I tried this works:

near-cli (feat/js-command) bin/near js call js-10.examples.benjiman.testnet getState --accountId <my-testnet-account> --args ''
Scheduling a call in JSVM[jsvm.testnet]: js-10.examples.benjiman.testnet.getState()

Receipt: 5WUa41BUXV1MQufNwrn9d2Kw4GD9Fi9sH5aX4dFBN5Am
	Log [jsvm.testnet]: Get state called!
	Log [jsvm.testnet]: row1: 1
	Log [jsvm.testnet]: row2: 2
	Log [jsvm.testnet]: row3: 3
	Log [jsvm.testnet]: row4: 4
	Log [jsvm.testnet]: row5: 5
	Log [jsvm.testnet]: player one: js-10.examples.benjiman.testnet
	Log [jsvm.testnet]: player two: benjiman.testnet
	Log [jsvm.testnet]: current turn: 1
	Log [jsvm.testnet]: game active: true
Transaction Id 8KbY5hQ7SwNAiHmy3WS2Td856Umzxvc4nCbdaAYQG6He
To see the transaction in the transaction explorer, please open this url in your browser
https://explorer.testnet.near.org/transactions/8KbY5hQ7SwNAiHmy3WS2Td856Umzxvc4nCbdaAYQG6He
''

[BenKurrek]

I’m pretty much copying exactly what’s being done in

near-sdk-js/examples/fungible-token/__tests__/test-fungible-token.ava.js

Line 52 in 63a5964

const result = await jsvm.view('view_js_contract', encodeCall(fungibleTokenContract.accountId, 'ftBalanceOf', [fungibleTokenContract.accountId]));

and I can’t get it to work

I copied over this function:

function encodeCall(contract, method, args) {
  return Buffer.concat([Buffer.from(contract), Buffer.from([0]), Buffer.from(method), Buffer.from([0]), Buffer.from(JSON.stringify(args))])
}

and am using it the following way (similar to what’s done in the workspace tests):

    const status = await account.functionCall("jsvm.testnet", 'call_js_contract', {
      args: encodeCall("js-10.examples.benjiman.testnet", 'getState', [])
    }, "300000000000000");

I’m getting the same error again

https://explorer.testnet.near.org/transactions/HJ7TjgsW7VwdYYG5B9KGjPwJQTBAigj2eDZbLisTP5e

[BenKurrek]

I've also tried the view function:

const statusView = await account.viewFunction("jsvm.testnet", 'view_js_contract', {
      args: encodeCall("js-10.examples.benjiman.testnet", 'getState', '')
    });

but this gives the same error

In addition, I've tried:

const statusView = await account.viewFunction("jsvm.testnet", 'view_js_contract',
      encodeCall("js-10.examples.benjiman.testnet", 'getState', '')
    );

[ailisp]

@BenKurrek Looking at @ChaoticTempest 's code, I think passing args directly (not {args: args}) work:

    const status = await account.functionCall("jsvm.testnet", 'call_js_contract', encodeCall("js-10.examples.benjiman.testnet", 'getState', []), "300000000000000");

or

let args =  encodeCall("js-10.examples.benjiman.testnet", 'getState', '')
const statusView = await account.viewFunction("jsvm.testnet", 'view_js_contract', args);

[ChaoticTempest]

what does your encodeCall look like?

[BenKurrek]

Ah you know what, I figured it out... I had copied over the encodeCall from the workspaces PR and forgot to check your CLI PR to see if you had any differences in your encode call.

I was using:

function encodeCall(contract, method, args) {
  return Buffer.concat([Buffer.from(contract), Buffer.from([0]), Buffer.from(method), Buffer.from([0]), Buffer.from(JSON.stringify(args))])
}

when I should have been using:

function encodeCall(contract, method, args) {
  return Buffer.concat([Buffer.from(contract), Buffer.from([0]), Buffer.from(method), Buffer.from([0]), Buffer.from(args)])
}

It works as expected now.

[ChaoticTempest]

nice, let me know if you run into anything else

[ailisp]

Nice! encodeCall is hard to get it right, we'll need to put it in the sdk-js! And @BenKurrek you just accomplished the first frontend of any near-sdk-js constract!

[BenKurrek]

Working code:

function encodeCall(contract, method, args) {
  return Buffer.concat([Buffer.from(contract), Buffer.from([0]), Buffer.from(method), Buffer.from([0]), Buffer.from(args)])
}

let args = encodeCall(contractId, 'getState', '');
const stateView = await wallet.account().viewFunction("jsvm.testnet", 'view_js_contract', args, {
  stringify: (val) => val,
});

and

function encodeCall(contract, method, args) {
  return Buffer.concat([Buffer.from(contract), Buffer.from([0]), Buffer.from(method), Buffer.from([0]), Buffer.from(args)])
}

let args = encodeCall(contractId, 'play', `["${selectedRow}", ${selectedNumber}]`);
const result = await wallet.account().functionCall({
  contractId: "jsvm.testnet",
  methodName: 'call_js_contract',
  args,
  gas: "300000000000000"
});

[BenKurrek]

Working code:

function encodeCall(contract, method, args) {
  return Buffer.concat([Buffer.from(contract), Buffer.from([0]), Buffer.from(method), Buffer.from([0]), Buffer.from(args)])
}

let args = encodeCall(contractId, 'getState', '');
const stateView = await wallet.account().viewFunction("jsvm.testnet", 'view_js_contract', args, {
  stringify: (val) => val,
});

and

function encodeCall(contract, method, args) {
  return Buffer.concat([Buffer.from(contract), Buffer.from([0]), Buffer.from(method), Buffer.from([0]), Buffer.from(args)])
}

let args = encodeCall(contractId, 'play', `["${selectedRow}", ${selectedNumber}]`);
const result = await wallet.account().functionCall({
  contractId: "jsvm.testnet",
  methodName: 'call_js_contract',
  args,
  gas: "300000000000000"
});