Ethereum: Error: Timeout of 900000ms exceeded. For async tests and hooks, ensure “done()” is called; if returning a Promise, ensure it resolves

Ethereum Error: 900,000ms Timeout Exceeded

As a developer working on Ethereum-based smart contracts in Hardhat, you may encounter the error “900,000ms Timeout Exceeded” when running unit tests for a lottery contract. This issue can occur if the test case is too slow to complete within the specified time frame.

Understanding the Error

The error message indicates that a timeout occurred because the execution time was longer than expected (900,000ms). However, this is not necessarily related to the quality or efficiency of the test case code. There are several factors that can cause this issue:

• Network Latency: Your smart contract may be running on a slow network connection, which is causing delays in test execution.

• High computational load: Performing complex simulations or generating large amounts of data can consume significant CPU and memory resources, causing the test case to time out.

• Asynchronous operations: Your test case may contain asynchronous operations (e.g. Web3 RPC calls, I/O-related tasks) that can take a long time to complete.

Workarounds

To resolve this issue, you can try the following workarounds:

• Optimize your code for asynchronous operations: Ensure that all asynchronous operations in your tests are properly awaited or handled using callbacks. You can use the ‘await’ keywords or ‘.then()’ to await asynchronous operations.

• Reduce computational load: Limit the amount of data generated, simulate scenarios, and reduce complex calculations in your test cases.

• Improve network connectivity: Optimize Web3 RPC calls and ensure a stable network connection with minimal latency.

• Use async/await-friendly libraries

  

  : Consider using libraries like “web3” or “ethers.js” that provide async-friendly interfaces for interacting with the Ethereum blockchain.

Solution example

Here is an updated unit test example that includes the following optimizations:

const { ethers } = require("hardhat");
description("Lottery Contract", () => {
let lotteryContract;
before(async function() {
// Load lottery contract
const [account1, account2] = await ethers.getSigners();
(await ethers.getContractFactory("Lottery")).then((lotteryContract) => {
lotteryContract.deploy(account1.address);
lotteryContract.deploy(account2.address);
return lotteryContract.deployed();
});
});
it("should pick a winner", async function() {
// Reset lottery
await (await lotteryContract.reset()).then(() => {
// Pick a winner
const result = await (await lotteryContract.pickWinner()).then((winner) => {
return ethers.utils.formatBytes(
"0x" + result,
["HEX"]
);
});
console.log(result);
});
});
});

By following these solutions and adjusting your test case to optimize for asynchronous operations, you should be able to resolve the timeout issue and successfully run your unit tests.

Additional Tips

• Note that timeouts can also occur due to external factors such as network congestion or unexpected issues with your blockchain provider.

• If you are experiencing persistent timeout issues, consider using a more robust testing framework such as “jest” or “mocha”.

• Always monitor the execution time of your test suite and adjust your tests accordingly to prevent timeouts.