Bug: unexpected zero gas_consumed

[xJonathanLEI]

Description

When calling starknet_estimateGas, the gas_consumed field returned in zero.

Steps to reproduce

Run this script:

#!/bin/sh

curl \
    "https://starknet.rpc.zklend.com" \
    -H "Content-Type: application/json" \
    -d '{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "starknet_estimateFee",
  "params": [
    {
      "calldata": [
        "0x1352dd0ac2a462cb53e4f125169b28f13bd6199091a9815c444dcae83056bbc"
      ],
      "contract_address": "0x49d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7",
      "entry_point_selector": "0x2e4263afad30923c891518314c3c95dbe830a16874e8abc5777a9a20b54c76e"
    },
    "0x0157b5a30652cf983bfddbd660bac463127902a68f7acefa62823963026850db"
  ]
}' | jq

Note: as of this writing the hosted node is running v0.2.3-alpha

Expected result

The field gas_consumed should be non-zero since the two other fields are also non-zero.

Actual result

{
  "jsonrpc": "2.0",
  "result": {
    "gas_consumed": "0x0",
    "gas_price": "0x68626f4a8",
    "overall_fee": "0x10fb9d68123"
  },
  "id": 1
}

[koivunej]

@xJonathanLEI with #429 on latest mainnet it now gives:

{
  "jsonrpc": "2.0",
  "result": {
    "gas_consumed": "0x29",
    "gas_price": "0x75cb793bb",
    "overall_fee": "0x132a27795c7"
  },
  "id": 1
}

But of course this now on a different block, and I cannot find the block you executed this on. Could you specify block hash and the network just in case if this doesn't look more correct? Let's keep this issue open until you've confirmed regardless of how #429 progresses.

[xJonathanLEI]

@koivunej My fault making the script non-deterministic. I've updated the script to use a block hash instead (response updated too).

[xJonathanLEI]

BTW my script was actually running against alpha-goerli. It won't work on alpha-mainnet after the update with the block hash.

[koivunej]

Oki I don't have the goerli snapshot at hand right now... Maybe you can test the PR branch directly or let us know how it looks later after merge? Feel free to close if this is okay approach.

It will be disputable if the floor or ceil operation on coercing the gas_consumed to integer over at python side is correct, or maybe it should be rounded. I went with floor/truncation for now, assuming that's what python does with int() function.

[xJonathanLEI]

No worries I have a mainnet node too :)

Script and response updated again for alpha-mainnet.

[koivunej]

Oki finally checked the latest version, the 0x29 gas used is the same from earlier testing:

{
  "jsonrpc": "2.0",
  "result": {
    "gas_consumed": "0x29",
    "gas_price": "0x68626f4a8",
    "overall_fee": "0x10fb9d68123"
  },
  "id": 1
}

Closing for now, feel free to ping/reopen.