Support state_override in eth_call and eth_estimateGas

[pdyraga]

Introduction

The pull request adds support for state_override in eth_call and eth_estimateGas methods.

Changes

The structure of stateOverride is based on the version from go-ethereum. I have also added SetBalance and SetStorage to StateDB, just like go-ethereum does. State overrides are optional and applied in ApplyMessageWithConfig, where we make sure state overrides can only be used for calls not committing the state.

Testing

Run the node locally with $ make localnet-bin-start and execute eth_call with state_override. Compare the outcome with one returned by RPC providers running the main version of the code.

curl -s -X POST http://localhost:8545 \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_call",
    "params": [
      {
        "to": "0x000000000000000000000000000000000000abcd",
        "data": "0x70a0823100000000000000000000000000000000000000000000000000000000deadbeef"
      },
      "latest",
      {
        "0x000000000000000000000000000000000000abcd": {
          "code": "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",
          "stateDiff": {
            "0x49361c85d50c86f43fdb7ff3f85f3cac00c47bda054279b6563a02b9b214ccf4": "0x00000000000000000000000000000000000000000000003635c9adc5dea00000"
          }
        }
      }
    ],
    "id": 1
  }'

Where:

• 0x00000000000000000000000000000000DeaDBeef - fake address for which we are setting balance
• 0x000000000000000000000000000000000000abcd - fake address of ERC20 smart contract
• 0x70a0823100000000000000000000000000000000000000000000000000000000deadbeef - balanceOf(0x...DeaDBeef)
• 0x6080604052348015610010576000... - ERC20 smart contract bytecode
• 0x49361c85... storage slot is keccak256(abi.encode(0xDeaDBeef, 0)) - the balance mapping slot for that address

The expected result on this branch is 0x...3635c9adc5dea00000 = 1000 * 10^18.

Calling eth_estimateGas with the same state overrides and calldata for transfer:

    "method": "eth_estimateGas",
    "params": [
      {
        "from": "0x00000000000000000000000000000000DeaDBeef",
        "to": "0x000000000000000000000000000000000000abcd",
        "data": "0xa9059cbb00000000000000000000000000000000000000000000000000000000cafebabe0000000000000000000000000000000000000000000000056bc75e2d63100000"
      },

should yield gas cost estimated.

---

Author's checklist

• Provided the appropriate description of the pull request
• Updated relevant unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Assigned myself in the Assignees field
• Assigned mezod-developers in the Reviewers field and notified them on Discord

Reviewer's checklist

• Confirmed all author's checklist items have been addressed
• Considered security implications of the code changes
• Considered performance implications of the code changes
• Tested the changes and summarized covered scenarios and results in a comment

[lukasz-zimnoch]

Tested and works as advertised! ✅