Using JSON strings as an ABI

[AlvaroLuken]

Ethers Version

6.3.0

Search Terms

No response

Describe the Problem

This is my code:

The issue is related to the Contract instance creation - whenever I comment that out, the error goes away. But when I comment that initialization back in, I get the following compilation error:

Code Snippet

const provider = new ethers.BrowserProvider(ethereum, "any");
const FAUCET_CONTRACT_ADDRESS = "0x9BdCbC868519Cf2907ECE4E9602346c3fC9e6c8e";
const abi = `[
    {
        "inputs": [],
        "name": "withdraw",
        "outputs": [],
        "stateMutability": "nonpayable",
        "type": "function"
    },
]`;

// this is what is causing the compile error for some reason
const faucetContract = new ethers.Contract(
  FAUCET_CONTRACT_ADDRESS,
  abi,
  provider.getSigner()
);

Contract ABI

No response

Errors

Unexpected token ']', ..."n"
    },
]" is not valid JSON
SyntaxError: Unexpected token ']', ..."n"
    },
]" is not valid JSON
    at JSON.parse (<anonymous>)
    at Interface.from (http://localhost:3000/static/js/bundle.js:79628:33)
    at new BaseContract (http://localhost:3000/static/js/bundle.js:81080:72)
    at new Contract (http://localhost:3000/static/js/bundle.js:81437:1)
    at ./src/App.js (http://localhost:3000/static/js/bundle.js:53:24)
    at options.factory (http://localhost:3000/static/js/bundle.js:92171:31)
    at __webpack_require__ (http://localhost:3000/static/js/bundle.js:91565:33)
    at fn (http://localhost:3000/static/js/bundle.js:91828:21)
    at ./src/index.js (http://localhost:3000/static/js/bundle.js:380:62)
    at options.factory (http://localhost:3000/static/js/bundle.js:92171:31)

Environment

Browser (Chrome, Safari, etc)

Environment (Other)

Using create-react-app so webpack

[ricmoo]

Can you remove the back ticks ("") around your abi` variable? It looks like you are passing in invalid JSON (there is a trailing comma). But you should just pass in the object directly.

[ricmoo]

If passing a string in as an ABI, it must be valid JSON. To check if your string is valid, you can use JSON.parse in your code, in which case you can just pass the parsed object. :)

The above JSON is invalid because it has a trailing comma (,) in the 8th line. It looks like it was likely cut-and-paste from a larger ABI, but it's important to note the JSON is very strict as to its grammar.