[SUGGESTION OF FIX] "TypeError: customChains is not iterable" When verifying contract.

[facundocastello]

PROBLEM

I get the next error when running 'verify' on typescript:

TypeError: customChains is not iterable
    at getEtherscanEndpoints (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/@nomiclabs/hardhat-etherscan/src/network/prober.ts:33:37)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async Environment._runTaskDefinition (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/hardhat/src/internal/core/runtime-environment.ts:308:14)
    at async Environment.run (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/hardhat/src/internal/core/runtime-environment.ts:156:14)
    at async SimpleTaskDefinition.verifySubtask [as action] (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/@nomiclabs/hardhat-etherscan/src/index.ts:209:30)
    at async Environment._runTaskDefinition (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/hardhat/src/internal/core/runtime-environment.ts:308:14)
    at async Environment.run (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/hardhat/src/internal/core/runtime-environment.ts:156:14)
    at async verify (/Users/facundocastello/projects/hardhat-starter-kit/helper-functions.ts:46:9)
    at async Object.deployFunction [as func] (/Users/facundocastello/projects/hardhat-starter-kit/deploy/13_Deploy_BasicNFT.ts:30:9)
    at async DeploymentsManager.executeDeployScripts (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/hardhat-deploy/src/DeploymentsManager.ts:1220:22

another error that you can see for the same reason is when running yarn hardhat verify --network <NETWORK> <CONTRACT_ADDRESS> <CONSTRUCTOR_PARAMETERS> is the next one:

TypeError: Cannot read properties of undefined (reading 'map')
    at verifyAllowedChains (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/@nomiclabs/hardhat-etherscan/src/config.ts:20:53)
    at SimpleTaskDefinition.verify (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/@nomiclabs/hardhat-etherscan/src/index.ts:152:22)
    at Environment._runTaskDefinition (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/hardhat/src/internal/core/runtime-environment.ts:308:35)
    at Environment.run (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/hardhat/src/internal/core/runtime-environment.ts:156:25)
    at main (/Users/facundocastello/projects/hardhat-starter-kit/node_modules/hardhat/src/internal/cli/cli.ts:272:17)

the solution is the same one.

SOLUTION

The fix is to add customChains: [], afther the element on this line: https://github.com/smartcontractkit/hardhat-starter-kit/blob/ca2bd3d1de672005c8db0fe747c659724e174a32/hardhat.config.ts#L73

so it will be like this

    etherscan: {
        // yarn hardhat verify --network <NETWORK> <CONTRACT_ADDRESS> <CONSTRUCTOR_PARAMETERS>
        apiKey: {
            polygon: POLYGONSCAN_API_KEY,
            goerli: ETHERSCAN_API_KEY,
        },
        customChains: [],
    },

[shawnesquivel]

I got the exact same error, and adding the property to etherscan as per your suggestion made my code work! Thank you 😁

    etherscan: {
        apiKey: ETHERSCAN_API_KEY,
        customChains: [],
    },

Would be great to get an explanation from the devs as to why this works.

[Bhavik-punmiya]

Thanks you solution worked for me

customChains: [],

[KevinFalah]

Thanks for the solution