hardhat-toolbox-viem

Use viem.deployContract from the connection returned by network.create() to get a fully typed contract instance. Call read methods like counter.read.x() and write methods like counter.write.inc(), with arguments type-checked against the ABI at compile time.

Use viem.assertions helpers such as revert, revertWith, revertWithCustomError, emit, and emitWithArgs, passing the unawaited transaction promise as the first argument. Argument matchers accept concrete values, predicate functions, or the anyValue helper.

Prefer the typed instance returned by viem.deployContract or viem.getContractAt. walletClient.writeContract has no ABI typing, so wrong arguments or value on non-payable functions slip through without TypeScript errors.

Yes, viem.deployContract is the canonical deploy step inside a loadFixture setup function. Destructure viem and networkHelpers from network.create(), then call networkHelpers.loadFixture with your deploy function.

Use viem.assertions.balancesHaveChanged with the unawaited transaction promise and an object mapping addresses to expected deltas. Positive values mean received ETH and negative values mean spent, before gas costs.