Problems debugging error when encoding a tuple for a write transaction

[aspiers]

I have a custom hardhat task which is attempting to call a contract with a write function which takes a tuple as the second parameter. It is failing with the following stack trace (after adding Error.stackTraceLimit = 100; to hardhat.config.ts):

An unexpected error occurred:

Error: invalid BigNumber value (argument="value", value=undefined, code=INVALID_ARGUMENT, version=bignumber/5.7.0)
    at Logger.makeError (/home/adam/myproject/node_modules/@ethersproject/abi/node_modules/@ethersproject/logger/src.ts/index.ts:269:28)
    at Logger.throwError (/home/adam/myproject/node_modules/@ethersproject/abi/node_modules/@ethersproject/logger/src.ts/index.ts:281:20)
    at Logger.throwArgumentError (/home/adam/myproject/node_modules/@ethersproject/abi/node_modules/@ethersproject/logger/src.ts/index.ts:285:21)
    at Function.BigNumber.from (/home/adam/myproject/node_modules/@ethersproject/abi/node_modules/@ethersproject/bignumber/src.ts/bignumber.ts:289:23)
    at NumberCoder.encode (/home/adam/myproject/node_modules/@ethersproject/abi/src.ts/coders/number.ts:25:27)
    at /home/adam/myproject/node_modules/@ethersproject/abi/src.ts/coders/array.ts:71:19
    at Array.forEach (<anonymous>)
    at pack (/home/adam/myproject/node_modules/@ethersproject/abi/src.ts/coders/array.ts:54:12)
    at TupleCoder.encode (/home/adam/myproject/node_modules/@ethersproject/abi/src.ts/coders/tuple.ts:54:20)
    at /home/adam/myproject/node_modules/@ethersproject/abi/src.ts/coders/array.ts:62:19
    at Array.forEach (<anonymous>)
    at pack (/home/adam/myproject/node_modules/@ethersproject/abi/src.ts/coders/array.ts:54:12)
    at TupleCoder.encode (/home/adam/myproject/node_modules/@ethersproject/abi/src.ts/coders/tuple.ts:54:20)
    at AbiCoder.encode (/home/adam/myproject/node_modules/@ethersproject/abi/src.ts/abi-coder.ts:111:15)
    at Interface._encodeParams (/home/adam/myproject/node_modules/@ethersproject/abi/src.ts/interface.ts:323:31)
    at Interface.encodeFunctionData (/home/adam/myproject/node_modules/@ethersproject/abi/src.ts/interface.ts:378:18)
    at /home/adam/myproject/node_modules/ethers/node_modules/@ethersproject/contracts/src.ts/index.ts:228:37
    at step (/home/adam/myproject/node_modules/ethers/node_modules/@ethersproject/contracts/lib/index.js:48:23)
    at Object.next (/home/adam/myproject/node_modules/ethers/node_modules/@ethersproject/contracts/lib/index.js:29:53)
    at fulfilled (/home/adam/myproject/node_modules/ethers/node_modules/@ethersproject/contracts/lib/index.js:20:58)
    at processTicksAndRejections (node:internal/process/task_queues:95:5) {
  reason: 'invalid BigNumber value',
  code: 'INVALID_ARGUMENT',
  argument: 'value',
  value: undefined
}

Here is the actual object I passed as the tuple parameter (as logged by console.log, with some bits modified to avoid irrelevant details distracting):

{
  name: '20180301',
  startTime: 1519862400,
  endTime: 1546214400,
  quantity: 12345,
  flag1: false,
  flag2: false,
  string1: '',
  string2: '',
  string3: '',
  string4: ''
}

Maybe it's just me, but I find this error message to be very unhelpful; it raises more questions than answers:

• In which part of the tuple was the problem located?
• Why did NumberCode.encode fail? Did I mistakenly pass a value which was supposed to be a BigNumber, or was it OK to pass a number and have ethers convert it?
• What does argument="value" mean? As you can see from the above, none of the values passed in the object were value.
• What does value=undefined mean? As you can see from the above, none of the values passed in the object were undefined`.
• Or perhaps did I make a more fundamental mistake, e.g. assuming that I can pass an object to represent a tuple? But I couldn't find this documented anywhere in the v5 docs - am I missing something?

If any one of these questions were answered by the error message, I'd probably be able to fill in the gaps through intelligent guesswork. But as it currently stands, I find this so cryptic that I'm just left scratching my head with no clear direction for what I should try next, except perhaps adding debugging within node_modules which is a pretty horrible last resort.

Am I being dumb or could the error message be improved? Thanks :-)

(BTW, another problem with this stack trace is that it doesn't expose what originally triggered this code , since it's hidden behind node.js's internal processTicksAndRejections. I wrote about that here, although I fear that may be due to a fundamental limitation in how node.js works.)

[aspiers]

I'm just left scratching my head with no clear direction for what I should try next, except perhaps adding debugging within node_modules which is a pretty horrible last resort.

Well, I tried that, and answered my own question:

Am I being dumb or could the error message be improved? Thanks :-)

Turns out it can be improved - here's a PR :-)

#3774

In the example above, I now see:

Error: Failed to encode _myTuple as tuple(string,uint64,uint64,uint256,uint64,bool,bool,string,string,string,string): value=20180301,1519862400,1546214400,,12345,false,false,,,,

Failed to encode fieldNameStupidlyMissedFromParamsObject as uint256: value=undefined

invalid BigNumber value (argument="value", value=undefined, code=INVALID_ARGUMENT, version=bignumber/5.7.0)

[aspiers]

I only just stumbled across the fact that I submitted almost exactly the same suggestion a year ago. But this time I actually proposed a fix, so that's some progress at least :-)