Test case from https://github.com/RiccardoBiosas/opium-call-option-example

BasicOpiumCallOptionExecutionTest.ts

  it("should execute the full margin option with the underlying's market price less than the strike price", async () => {
    const { buyer, oracle } = namedSigners;

    /**
     * @dev time-travel after the maturity of the derivative
     */
    await timeTravel(SECONDS_40_MINS + 100);
    /**
     * @dev manually pushes the current underlying's market price to the oracle contract
     */
    await adminOracleController.connect(oracle).__callback(fullMarginOption.derivative.endTime, fullMarginOption.price);

    /**
     * @dev seller and buyer approve the execution of the derivative from a third-party (optionController)
     */
    await optionCallMock.connect(optionSeller).allowThirdpartyExecution(true);
    await optionCallMock.connect(buyer).allowThirdpartyExecution(true);

    const buyerBalanceBefore = await dai.balanceOf(buyer.address);
    const sellerBalanceBefore = await dai.balanceOf(daiRichEOA);

    /**
     * @dev calculates the buyer/seller payout for a given underlying's market price
     */
    const [buyerPayout, sellerPayout] = await optionCallMock.getExecutionPayout(
      fullMarginOption.derivative,
      fullMarginOption.price,
    );

    /**
     * @dev buyer and seller execute their LONG/SHORT positions
     */
    await optionController.connect(optionSeller).executeShort(fullMarginOption.amount);
    await optionController.connect(buyer).executeLong(fullMarginOption.amount);

    const buyerBalanceAfter = await dai.balanceOf(buyer.address);
    const sellerBalanceAfter = await dai.balanceOf(daiRichEOA);

    /**
     * @dev underlying's market price is less than the strike price so the seller receives the calculated payout
     */
    expect(buyerPayout, "wrong buyer payout").to.be.equal(0);
    expect(sellerPayout.mul(fullMarginOption.amount), "wrong seller payout").to.be.equal(
      fullMarginOption.derivative.margin.mul(fullMarginOption.amount),
    );
    expect(sellerBalanceAfter, "wrong seller balance").to.be.equal(
      sellerBalanceBefore.add(sellerPayout.mul(fullMarginOption.amount)),
    );
    expect(buyerBalanceAfter, "wrong buyer balance").to.be.equal(
      buyerBalanceBefore.add(buyerPayout.mul(fullMarginOption.amount)),
    );
  });