BatchRequest assumes JSON RPC requests are returned in order

[floatcoder]

Expected behavior

The response to a batch JSON RPC is not enforced to be in order (according to the spec). Despite most endpoints following this convention, some (e.g. Erigon) do not.

This means that results can be misparsed, or worse, silently corrupted despite the response being valid.

For example if we batched the following calls from G-UNI FLOAT/USDC contract:

• getUnderlyingBalances(uint256,uint256)
• totalSupply(uint256)

We can receive the response:

[
  {
    "jsonrpc": "2.0",
    "id": 2,
    "result": "0x0000000000000000000000000000000000000000000000058002c3cbfcb15f17"
  },
  {
    "jsonrpc": "2.0",
    "id": 1,
    "result": "0x000000000000000000000000000000000000000000000000000001dee1b1ea2a00000000000000000000000000000000000000000000c419a8b582118ad911b6"
  }
]

Which is valid and should decode to:

• (amount0Current, amount1Current) = 2056780900906, 926057156010074212733366
• totalSupply = 101457870636241215255

Actual behavior

In actuality, the response for totalSupply is attempted to be decoded as a tuple.

index.js:1 G-UNI USDC/FLOAT:getUnderlyingBalances.call Error: data out-of-bounds (length=32, offset=64, code=BUFFER_OVERRUN, version=abi/5.0.7)
    at Logger.makeError (index.ts:213)
    at Logger.throwError (index.ts:225)
    at Reader._peekBytes (abstract-coder.ts:182)
    at Reader.readBytes (abstract-coder.ts:196)
    at Reader.readValue (abstract-coder.ts:203)
    at NumberCoder.decode (number.ts:44)
    at array.ts:108
    at Array.forEach (<anonymous>)
    at unpack (array.ts:89)
    at TupleCoder.decode (tuple.ts:27)
    at AbiCoder.decode (abi-coder.ts:113)
    at ABICoder.push../node_modules/web3-eth-contract/node_modules/web3-eth-abi/lib/index.js.ABICoder.decodeParametersWith (index.js:303)
    at ABICoder.push../node_modules/web3-eth-contract/node_modules/web3-eth-abi/lib/index.js.ABICoder.decodeParameters (index.js:284)
    at push../node_modules/web3-eth-contract/lib/index.js.Contract._decodeMethodReturn (index.js:469)
    at batch.js:58
    at Array.forEach (<anonymous>)
    at batch.js:49
    at index.js:186
    at XMLHttpRequest.request.onreadystatechange (index.js:98)

Environment

yarn 1.22.4

web3-eth-contract@1.5.1, web3-eth-contract@^1.3.1:
  version "1.5.1"
  resolved "https://registry.yarnpkg.com/web3-eth-contract/-/web3-eth-contract-1.5.1.tgz#4c59abe3e575920e83e8f8c1bc0bf8a18f975623"
  integrity sha512-LRzFnogxeZagxHVpJ9cDK5Y8oQFUNtNL8s5w4IjvZ/JDoBQXPJuwhySwjftL3Hlk3znziMFqAH6snoxjvHnoag==
  dependencies:
    "@types/bn.js" "^4.11.5"
    web3-core "1.5.1"
    web3-core-helpers "1.5.1"
    web3-core-method "1.5.1"
    web3-core-promievent "1.5.1"
    web3-core-subscriptions "1.5.1"
    web3-eth-abi "1.5.1"
    web3-utils "1.5.1"

[floatcoder]

An easy fix would be to perform a sort by id at https://github.com/ChainSafe/web3.js/blob/1.x/packages/web3-core-requestmanager/src/batch.js#L51, happy to open a MR to do that if that's the preferred fix.

[spacesailor24]

Hi there, thank you for bringing this to our attention with so much detail!

The team's efforts right now is focused on getting the rewrite (4.x branch) done so we have a more straightforward code base to work with. If you are able to get a pull request up for this, we can review it and get it merged in, otherwise we don't have a guarantee on when this issue will be addressed

[philknows]

Echoing above from @spacesailor24 , there is no guarantee on when this will be addressed as resources are being used for 4.x branch to help better address issues such as this. We will push to get someone to check #4274 when possible.