Overflow error in hardhat-chai-matchers -> changeTokenBalances

[Pafaul]

Hi! When using packange hardhat-chai-matchers I've discovered issue with changeTokenBalances function:

     Error: overflow [ See: https://links.ethers.org/v5-errors-NUMERIC_FAULT-overflow ] (fault="overflow", operation="BigNumber.from", value=-99899990019000000000, code=NUMERIC_FAULT, version=bignumber/5.7.0)
      at Logger.makeError (node_modules/ethers/node_modules/@ethersproject/logger/src.ts/index.ts:269:28)
      at Logger.throwError (node_modules/ethers/node_modules/@ethersproject/logger/src.ts/index.ts:281:20)
      at throwFault (node_modules/ethers/node_modules/@ethersproject/bignumber/src.ts/bignumber.ts:356:19)
      at Function.BigNumber.from (node_modules/ethers/node_modules/@ethersproject/bignumber/src.ts/bignumber.ts:247:17)
      at ${projectPath}/node_modules/@nomicfoundation/hardhat-chai-matchers/src/internal/changeTokenBalance.ts:101:40
      at Array.every (<anonymous>)
      at checkBalanceChanges (node_modules/@nomicfoundation/hardhat-chai-matchers/src/internal/changeTokenBalance.ts:100:25)
      at async Context.<anonymous> (hhTest/test.js:619:9)

This matcher cannot check big values which is common for tokens with 18 decimals (for example - ten tokens with 18 decimals is 10000000000000000000 which leads to overflow).

Test which was runned:

await expect(
            txPromise
        ).to.emit(
            contract, event
        ).withArgs(
            ...eventArgs
        ).and.changeTokenBalances(
            tokens[0],
            [unknownUser.address, otherContract.address],
            [-amountIn, amountOut]
        ).and.changeTokenBalances(
            tokens[1],
            [unknownUser.address, otherContract.address],
            [expectedAmountOut, -expectedAmountOut]
        )

Both amountIn and expectedAmountOut are BigNumber instances but in stacktrace values are displayed as Numbers.

[github-actions[bot]]

This issue is also being tracked on Linear.

We use Linear to manage our development process, but we keep the conversations on Github.

LINEAR-ID: 24420fce-6148-4ddc-8976-a9dc5d6816d6

[Pafaul]

Update: Forgot to mention setup:

• hardhat-chai-matchers: 1.0.3
• hardhat: 2.10.2
• node: v18.6.0
• environment: WSL2 with Ubuntu 20.04.4 LTS

[Pafaul]

Update #2: For local tests it is sometimes possible to lower decimals to 6-12 to avoid this issue, but for real-world application it may not be possible (for example - when working with forked network)

[feuGeneA]

This issue has been added to our internal backlog, meaning that we intend to work on it, but that it has not yet been scheduled.

[Pafaul]

Hi @feuGeneA ! Any updates on issue?

[heycryptobob]

I am having the same issue :(

[fvictorio]

Hi folks. In these cases, you should use a BigInt value instead of a number. That is, instead of 10000000000000000000, you should use 10000000000000000000n (notice the trailing n).

That being said, we should show a better error in these scenarios. I'm going to open a new issue for that, and close this one in favor of it.

[Pafaul]

Thanks for the information!