The Melon Bot's Magic Function

MelonBot.MagicFunction.ts

  public fortuneTeller(expectedPrice: PriceQueryResult) {
    // this is my sophisticated trading strategy. you could build
    // something more elaborate with the PriceQueryResult object passed in. 
    return Math.random() > 0.5;
  }

  public async makeMeRich() {
    // call the getFundHoldings method which returns an array of holdings.
    const balances = await this.accountingContract.getFundHoldings();

    // deduce holdings in each token your bot cares about
    const tokenOneHolding =
      balances.find((balance) => sameAddress(balance.address, this.tokenOne.address))?.amount || new BigNumber(0);

    const tokenTwoHolding =
      balances.find((balance) => sameAddress(balance.address, this.tokenTwo.address))?.amount || new BigNumber(0);

    /**
     * Specific to my strategy, where we are either long MLN or long ETH but never long both,
     * baseCurrency is the currency with holdings, quote currency is the currency without.
     * It will be the case that they're both non-zero only if the bot starts running
     * with balances that it has not traded. In that case, I've set MLN to be
     * the base ccy (bot will sell MLN balance buy WETH)
     */
    const baseCurrency = tokenOneHolding.isGreaterThan(tokenTwoHolding) ? this.tokenOne : this.tokenTwo;
    const quoteCurrency = baseCurrency === this.tokenOne ? this.tokenTwo : this.tokenOne;
    const baseQuantity = baseCurrency === this.tokenOne ? tokenOneHolding : tokenTwoHolding;

    // pass them all to the getPrice function to see what the rates are
    const priceObject = await this.getPrice(baseCurrency, quoteCurrency, baseQuantity);

    if (this.fortuneTeller(priceObject)) {
      return this.makeTransaction(priceObject);
    }

    return null;
  }