Hardhat artifacts and viem

[josemarinas]

Hello,

We are using Hardhat for compiling our contracts, we need to use the resulting artifacts with viem but we dont get the typesafety because they are not exported as const so viem does not detect them. Is there any way of solving this issue or whats the bes way of proceeding?

Thank you very much in advance

@fvictorio

[schaable]

Hi @josemarinas, are you using the hardhat-viem plugin? Can you describe what you're trying to do?

[schaable]

hardhat-viem provides type generation for your contracts upon compilation. It automatically generates a type file for your contract under the artifacts directory, which includes the ABI. For instance, for the Lock contract, it generates something like this:

Is this what you're looking for?

[josemarinas]

Yep, it seems like it however, I haven't been able to set it up properly.

I added the hardhat-viem and viem libraries

yarn add --dev hardhat-viem viem

Then i added this line to my hardhat.config.ts

// hardhat.config.ts
import '@nomicfoundation/hardhat-viem';

But the artifacts generated after building the contracts does not seem to change, however viem is available in the hre object. Is there something that I'm missing?

[schaable]

What do you mean by saying the artifacts don't seem to change? Typically, artifacts (including types) are regenerated each time you execute hardhat compile, provided there have been modifications to your contracts. Is that not happening for you? If that's the case, could you provide the steps your following so we can try to replicate?

[josemarinas]

I managed to generate the artifacts but now I didnt manage to use them with viem. My final objective is to crteate an npm package that holds this artifacts. I tried multiple stuff but they dont seem to be usable in TS outside of the Hardhat project.

I would like to use them like this

import * as artifacts from '..artifacts';
import hre from 'hardhat';
import {getContract} from 'viem';

async function main() {
  const contract = getContract({
    client,
    address: '0x1234567890123456789012345678901234567890',
    abi: artifacts.contract.abi // selecting the correct abi
  });

  const contract.write.function(params1, param2 ...)
}

main()
  .then(() => process.exit())
  .catch(error => {
    console.error(error);
    process.exit(1);
  });

[schaable]

That's not the correct way of using an artifact. Here´s an example:

import hre from 'hardhat';
// ...
const artifact = await hre.artifacts.readArtifact("MyContract");
console.log(artifact.abi)

they dont seem to be usable in TS outside of the Hardhat project.

If you want to read the artifacts generated by hardhat from outside the hardhat project, you could import them directly:

import myContractArtifact from 'some/path/hardhat-project/artifacts/contracts/MyContract.sol/MyContract.json';
console.log(myContractArtifact.abi)

[mdesousa]

i was able to generate abi.ts by adding the subtask below to the hardhat config. it exports the abi as a constant, so it can be used as shown in viem type inference. hope it helps!

type ContractMap = Record<string, { abi: object }>;

subtask(TASK_COMPILE_SOLIDITY_EMIT_ARTIFACTS).setAction(
  async (args, env, next) => {
    const output = await next();
    const { artifacts } = env.config.paths;
    const promises = Object.entries(args.output.contracts).map(
      async ([sourceName, contract]) => {
        const file = join(artifacts, sourceName, 'abi.ts');
        const { abi } = Object.values(contract as ContractMap)[0];
        const data = `export const abi = ${inspect(abi, false, null)} as const;`;
        await writeFile(file, data);
      },
    );
    await Promise.all(promises);
    return output;
  },
);

[sshmaxime]

Hey @josemarinas , I'm facing the exact same issue. Did you figure it out ?

[josemarinas]

Yes, in the end I used wagmi-cli with this wagmi.config.ts, you'd need to update the paths to your own. Then you can import the generated abi with viem

import {defineConfig} from '@wagmi/cli';
import {hardhat} from '@wagmi/cli/plugins';

export default defineConfig({
  // using abi instead of generated to avoid being ignored by git
  out: `generated/abis.ts`,
  plugins: [
    hardhat({
      artifacts: `../contracts/artifacts/src`,
      exclude: ['**/test'],
      project: '../contracts',
    }),
  ],
});

[sshmaxime]

Yeah, I ended up doing the same. Thanks anyway buddy 👌