fix(ethers-v6): TypedContractEvent should extend EventLog

[songkeys]

This is to align with v5:

import type { Event } from "ethers";

export interface TypedEvent<
  TArgsArray extends Array<any> = any,
  TArgsObject = any
> extends Event {
  args: TArgsArray & TArgsObject;
}

so that we can type the event log with it.

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[zemse]

There is a TypedEventLog in the same file, which is the return type for queryFilter. The TypedEvent in v5 is similar to TypedEventLog in v6.

However, TypedContractEvent is a different thing, it is a proxy function that can be used to generate a filter. Maybe we can change its name if it's not the best.

I don't think extending EventLog here would not be appropriate, are you facing any type issues?

Types in ethers v6 without typechain:

contract.filters.Transfer // ContractEvent
contract.getEvent('Transfer') // ContractEvent

contract.filters.Transfer('0x123') // DeferredTopicFilter

contract.queryFilter(contract.filters.Transfer) // EventLog

with typechain:

import {ERC20} from '../typechain'

contract.filters.Transfer // ERC20.TransferEvent.Event
contract.getEvent('Transfer') // ERC20.TransferEvent.Event

contract.filters.Transfer('0x123') // TypedDeferredTopicFilter<ERC20.TransferEvent.Event>;

contract.queryFilter(contract.filters.Transfer) // TypedEventLog<ERC20.TransferEvent.Event>

[songkeys]

How do I type the event log?

In v5, I type them like this:

    import type { MintEvent } from '../Abi'


    const targetTopicHash = keccak256(toUtf8Bytes('Mint(uint256,uint256,uint256)')

    // txReceipt.logs
    const _logs = logs.filter((log) => log.topics[0] === targetTopicHash)

    if (_logs.length === 0) {
      throw new Error(`Log with topic ${filterTopic} not found`)
    }

    const log = _logs[0]

    return this.contract.interface.parseLog(log) as unknown as MintEvent

In v6, the MintEvent (XxxEvent) turns into an namespace which includes an Event type:

export namespace MintEvent {
  export type InputTuple = [
    to: BigNumberish,
    tokenId: BigNumberish,
    tokenNumber: BigNumberish
  ];
  export type OutputTuple = [to: bigint, tokenId: bigint, tokenNumber: bigint];
  export interface OutputObject {
    to: bigint;
    tokenId: bigint;
    tokenNumber: bigint;
  }
  export type Event = TypedContractEvent<InputTuple, OutputTuple, OutputObject>;
  export type Filter = TypedDeferredTopicFilter<Event>;
}

But the MintEvent.Event type (TypedContractEvent) doesn't extends EventLog to be compatible with LogDescription.

I tried using TypedEventLog<MintEvent.Event> but got this error:

type MintEvent.Event = TypedContractEvent<MintEvent.InputTuple, MintEvent.OutputTuple, MintEvent.OutputObject>
Type 'Event' does not satisfy the constraint 'TypedContractEvent<any, any, any>'.
  Types of parameters 'to' and 'args' are incompatible.
    Type 'Partial<any>' is not assignable to type '[to?: BigNumberish | undefined, tokenId?: BigNumberish | undefined, tokenNumber?: BigNumberish | undefined]'.ts(2344)

TypedEventLog<TransferEvent.Event> works fine actually.

Do you have any suggestions? thanks.

---

Edit: I should state the overall request: to type the logs of tx receipt. More specifically,

const tx = await abi.mint({ ... })
const receipt = await tx.wait()
const parsedLog = parseLog(receipt.logs, 'Mint(uint256,uint256,uint256)')
console.log(parsedLog.args.tokenId.toNumber())

I wrote the parseLog function manually in v5 and type the returned value as described above. But I have no clue to find the type in v6.

[zemse]

But the MintEvent.Event type (TypedContractEvent) doesn't extends EventLog to be compatible with LogDescription.

Yea, MintEvent.Event will not work but TypedEventLog<MintEvent.Event> should work since it extends EventLog. To prevent further confusion I think we should rename this to something else.

I tried using TypedEventLog<MintEvent.Event> but got this error
TypedEventLog<TransferEvent.Event> works fine actually.

Do you mean Transfer event works but Mint event gives type errors?

Can you try this once?

const parsedLog = parseLog(receipt.logs, 'Mint(uint256,uint256,uint256)') as unknown as TypedEventLog<MintEvent.Event>[]

You should be able to access .args since it is available in both EventLog and LogDescription. But for full compatibility (without requiring to cast into unknown), I can add a TypedLogDescription here.

[songkeys]

Do you mean Transfer event works but Mint event gives type errors?

Yes. I pasted the error in the above comment. I paste here again:

The MintEvent generated for me is:

export namespace MintEvent {
  export type InputTuple = [
    to: BigNumberish,
    tokenId: BigNumberish,
    tokenNumber: BigNumberish
  ];
  export type OutputTuple = [to: bigint, tokenId: bigint, tokenNumber: bigint];
  export interface OutputObject {
    to: bigint;
    tokenId: bigint;
    tokenNumber: bigint;
  }
  export type Event = TypedContractEvent<InputTuple, OutputTuple, OutputObject>;
  export type Filter = TypedDeferredTopicFilter<Event>;
}

The error for TypedEventLog<MintEvent.Event> is:

type MintEvent.Event = TypedContractEvent<MintEvent.InputTuple, MintEvent.OutputTuple, MintEvent.OutputObject>
Type 'Event' does not satisfy the constraint 'TypedContractEvent<any, any, any>'.
  Types of parameters 'to' and 'args' are incompatible.
    Type 'Partial<any>' is not assignable to type '[to?: BigNumberish | undefined, tokenId?: BigNumberish | undefined, tokenNumber?: BigNumberish | undefined]'.ts(2344)