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[ethers-v5] Error generating code for events with tuples

See original GitHub issue

When an event definition includes a tuple among its arguments, the generated code in the corresponding .d.ts file is invalid for the ethers-v5 target.

I have reproduced this problem using the latest code from the master branch (matches tag @typechain/ethers-v5@6.0.3). I have simply added an event with a tuple to the examples/ethers-v5/abi/dai.json file, as shown in this fork’s commit.

Namely, I included an event definition as such in examples/ethers-v5/abi/dai.json:

  {
    "anonymous": false,
    "inputs": [
      { "indexed": true, "internalType": "address", "name": "src", "type": "address" },
      {
        "indexed": false,
        "name": "data",
        "type": "tuple",
        "components": [
          { "name": "index", "type": "uint256" },
          { "name": "name", "type": "string" }
        ]
      }
    ],
    "name": "Tuple",
    "type": "event"
  }

Then the generated code in the examples/ethers-v5/types/ethers-contracts/Dai.d.ts is:

    Tuple(
      src: string | null,
      data: null
    ): TypedEventFilter<
      [string, [BigNumber, string], { index: BigNumber; name: string }] & {
        src: string;
        data: [BigNumber, string] & { index: BigNumber; name: string };
      }
    >;

Which leads to the following error when running yarn typecheck within examples/ethers-v5

$ yarn typecheck
yarn run v1.22.5
$ tsc --noEmit
types/ethers-contracts/Dai.d.ts:837:8 - error TS2314: Generic type 'TypedEventFilter<EventArgsArray, EventArgsObject>' requires 2 type argument(s).

837     ): TypedEventFilter<
           ~~~~~~~~~~~~~~~~~
838       [string, [BigNumber, string], { index: BigNumber; name: string }] & {
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
... 
841       }
    ~~~~~~~
842     >;
    ~~~~~


Found 1 error.

error Command failed with exit code 2.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

At first glance, it seems to me that the correct output would be to switch the position of , and & as follows:

    Tuple(
      src: string | null,
      data: null
    ): TypedEventFilter<
      [string, [BigNumber, string]& { index: BigNumber; name: string }] , {  // <---- switched `&` and `,` here
        src: string;
        data: [BigNumber, string] & { index: BigNumber; name: string };
      }
    >;