Timestamp is lower than or equal to previous block

Question

I have a function where a specific time should be passed to run it.

function placeBid(...) {
  require(auction.startedAt <= block.timestamp, "not started yet");
  ...
}

say startedAt is a unix value of 1648198972 I'm testing with

    beforeEach(async function () {
      await ethers.provider.send("evm_setNextBlockTimestamp", [parseInt(auction.startedAt)]);
      await ethers.provider.send("evm_mine");
    });

      expect(await Auction.connect(user2).placeBid(...))});

describe("Success", function () {
      it("Should send bid to previous bidder", async function () {
        expect(bidder).to.equal(user2.address);
        block = await ethers.provider.getBlock("latest");
        console.log("current: ", block.timestamp)
      });
      it("....", async function () {
       ...
      });
});

This can actually run placeBid which seems it passed the require statement, but I get an error related to timestamp!

Truth is, it always passes the first it statement, but it throws this timestamp error when it goes to the next it statement.

InvalidInputError: Timestamp 1648198972 is lower than or equal to previous block's timestamp 1648198986

what's wrong?

Answer 1

As per this answer -

Keep in mind that Hardhat Network validates that the new timestamp is bigger than the previous one, so you can't send any value.

It appears that the issue stems from the fact that you're trying to mine a new block in the past (by setting a timestamp before the last block) leading to the given error.

A simple fix could be to modify startedAt to a timestamp in the distant future so that this error can be avoided altogether.