Big numbers in test file

[zach-is-my-name]

How is it possible to initialize BondingCurveMock.sol with big numbers such as:

  const startSupply = 10 * 1e18; 
    instance = await BondingCurveMock.new(
      startSupply,
      solRatio,
      gasPrice,
      { value: startPoolBalance, from: accounts[0] }
    );

I'm using Truffle 5.0.27 but I feel like I'd need to pass startSupply or any javascript number > Number.MAX_SAFE_INTEGER into a bignumber constructor at some point...

anyway the test fails with this same error:
web3/web3.js#2077