How can I mock the time for solidity tests?

Question

My contract has an expiration date that I'd like to unit test but I don't know how to go about doing that. If I could mock the time of the contract that would be dope. Google search provided no information though.

Answer 1

As a general testing method, you can create another, debugging-only, contract descending from your production contract. This second contract can have methods to do anything--for example, to set the expiration date to now.

If you want to mess with time specifically, TestRPC has an RPC method to fast forward time. Be warned, you'll have to integrate it into your testing harness somehow, since web3 does not come with it.

Answer 2

This is a fairly old question but I thought I would add this for those looking:

You can utilize the evm_increaseTime method that you get with both hardhat and ganache.

Here's an example with ethers

await ethers.provider.send("evm_increaseTime", [10]) // add 10 seconds
await ethers.provider.send("evm_mine", []) // force mine the next block

And here with web3

web3.currentProvider.send({jsonrpc: "2.0", method: "evm_increaseTime", params: [10], id: 0})
web3.currentProvider.send({jsonrpc: "2.0", method: "evm_mine", params: [], id: 0})

Answer 3

I've been making my contracts descend from a simple contract that has a currTime() function and a testing boolean. If I set testing to true, currTime() returns a fake time, which I can manipulate with functions like addDays(uint days). If testing is false, then currTime() just returns block.timestamp. Every place where I'd check the timestamp, I call currTime() instead.

Answer 4

There is a library in Dapphub: https://github.com/dapphub/ds-warp

A simple mixin for controlling time.

Return the current time with era(). Advance time with warp.

warp(0) to lock the current time to the blocktime.

contract DSWarpTest is DSTest {
    DSWarp warp;

    function setUp() {
        warp = new DSWarp();
    }
    function testInit() {
        assertEq(warp.era(), now);
    }
    function testWarp() {
        var tic = now;
        warp.warp(1);
        assertEq(warp.era(), tic + 1);
    }
    function testWarpLock() {
        warp.warp(0);
        assertEq(warp.era(), now);
    }
    function testFailAfterWarpLock() {
        warp.warp(0);
        warp.warp(1);
    }
}