bitburner-src/test/StockMarketTests.js

import { CONSTANTS } from "../src/Constants";
import { Order } from "../src/StockMarket/Order";
import { processOrders } from "../src/StockMarket/OrderProcessing";
import { Stock } from "../src/StockMarket/Stock";
import {
    deleteStockMarket,
    initStockMarket,
    initSymbolToStockMap,
    loadStockMarket,
    StockMarket,
    SymbolToStockMap,
} from "../src/StockMarket/StockMarket";
import {
    calculateIncreasingPriceMovement,
    calculateDecreasingPriceMovement,
    forecastChangePerPriceMovement,
    getBuyTransactionCost,
    getSellTransactionGain,
    processBuyTransactionPriceMovement,
    processSellTransactionPriceMovement,
} from "../src/StockMarket/StockMarketHelpers";
import { OrderTypes } from "../src/StockMarket/data/OrderTypes"
import { PositionTypes } from "../src/StockMarket/data/PositionTypes";

//const assert = chai.assert;
//const expect = chai.expect;
import { expect } from "chai";

console.log("Beginning Stock Market Tests");

describe("Stock Market Tests", function() {
    const commission = CONSTANTS.StockMarketCommission;

    // Generic Stock object that can be used by each test
    let stock;
    const ctorParams = {
        b: true,
        initPrice: 10e3,
        marketCap: 5e9,
        mv: 1,
        name: "MockStock",
        otlkMag: 10,
        spreadPerc: 1,
        shareTxForMovement: 5e3,
        symbol: "mock",
    };

    beforeEach(function() {
        function construct() {
            stock = new Stock(ctorParams);
        }

        expect(construct).to.not.throw();
    });

    describe("Stock Class", function() {
        describe("constructor", function() {
            it("should have default parameters", function() {
                let defaultStock;
                function construct() {
                    defaultStock = new Stock();
                }

                expect(construct).to.not.throw();
                expect(defaultStock.name).to.equal("");
            });

            it("should properly initialize props from parameters", function() {
                expect(stock.name).to.equal(ctorParams.name);
                expect(stock.symbol).to.equal(ctorParams.symbol);
                expect(stock.price).to.equal(ctorParams.initPrice);
                expect(stock.lastPrice).to.equal(ctorParams.initPrice);
                expect(stock.b).to.equal(ctorParams.b);
                expect(stock.mv).to.equal(ctorParams.mv);
                expect(stock.shareTxForMovement).to.equal(ctorParams.shareTxForMovement);
                expect(stock.shareTxUntilMovement).to.equal(ctorParams.shareTxForMovement);
                expect(stock.maxShares).to.be.below(stock.totalShares);
                expect(stock.spreadPerc).to.equal(ctorParams.spreadPerc);
                expect(stock.priceMovementPerc).to.be.a("number");
                expect(stock.priceMovementPerc).to.be.at.most(stock.spreadPerc);
                expect(stock.priceMovementPerc).to.be.at.least(0);
            });

            it ("should properly initialize props from range-values", function() {
                let stock;
                const params = {
                    b: true,
                    initPrice: {
                        max: 10e3,
                        min: 1e3,
                    },
                    marketCap: 5e9,
                    mv: {
                        divisor: 100,
                        max: 150,
                        min: 50,
                    },
                    name: "MockStock",
                    otlkMag: 10,
                    spreadPerc: {
                        divisor: 10,
                        max: 10,
                        min: 1,
                    },
                    shareTxForMovement: {
                        max: 10e3,
                        min: 5e3,
                    },
                    symbol: "mock",
                };

                function construct() {
                    stock = new Stock(params);
                }

                expect(construct).to.not.throw();
                expect(stock.price).to.be.within(params.initPrice.min, params.initPrice.max);
                expect(stock.mv).to.be.within(params.mv.min / params.mv.divisor, params.mv.max / params.mv.divisor);
                expect(stock.spreadPerc).to.be.within(params.spreadPerc.min / params.spreadPerc.divisor, params.spreadPerc.max / params.spreadPerc.divisor);
                expect(stock.shareTxForMovement).to.be.within(params.shareTxForMovement.min, params.shareTxForMovement.max);
            });

            it("should round the 'totalShare' prop to the nearest 100k", function() {
                expect(stock.totalShares % 100e3).to.equal(0);
            });
        });

        describe("#changePrice()", function() {
            it("should set both the last price and current price properties", function() {
                const newPrice = 20e3;
                stock.changePrice(newPrice);
                expect(stock.lastPrice).to.equal(ctorParams.initPrice);
                expect(stock.price).to.equal(newPrice);
            });
        });

        describe("#getAskPrice()", function() {
            it("should return the price increased by spread percentage", function() {
                const perc = stock.spreadPerc / 100;
                expect(perc).to.be.at.most(1);
                expect(perc).to.be.at.least(0);

                const expected = stock.price * (1 + perc);
                expect(stock.getAskPrice()).to.equal(expected);
            });
        });

        describe("#getBidPrice()", function() {
            it("should return the price decreased by spread percentage", function() {
                const perc = stock.spreadPerc / 100;
                expect(perc).to.be.at.most(1);
                expect(perc).to.be.at.least(0);

                const expected = stock.price * (1 - perc);
                expect(stock.getBidPrice()).to.equal(expected);
            });
        });
    });

    describe("StockMarket object", function() {
        describe("Initialization", function() {
            // Keeps track of initialized stocks. Contains their symbols
            const stocks = [];

            before(function() {
                expect(initStockMarket).to.not.throw();
                expect(initSymbolToStockMap).to.not.throw();
            });

            it("should have Stock objects", function() {
                for (const prop in StockMarket) {
                    const stock = StockMarket[prop];
                    if (stock instanceof Stock) {
                        stocks.push(stock.symbol);
                    }
                }

                // We'll just check that there are some stocks
                expect(stocks.length).to.be.at.least(1);
            });

            it("should have an order book in the 'Orders' property", function() {
                expect(StockMarket).to.have.property("Orders");

                const orderbook = StockMarket["Orders"];
                for (const symbol of stocks) {
                    const ordersForStock = orderbook[symbol];
                    expect(ordersForStock).to.be.an("array");
                    expect(ordersForStock.length).to.equal(0);
                }
            });

            it("should have properties for managing game cycles", function() {
                expect(StockMarket).to.have.property("storedCycles");
                expect(StockMarket).to.have.property("lastUpdate");
            });
        });

        // Because 'StockMarket' is a global object, the effects of initialization from
        // the block above should still stand
        describe("Deletion", function() {
            it("should set StockMarket to be an empty object", function() {
                expect(StockMarket).to.be.an("object").that.is.not.empty;
                deleteStockMarket();
                expect(StockMarket).to.be.an("object").that.is.empty;
            });
        });

        // Reset stock market for each test
        beforeEach(function() {
            deleteStockMarket();
            initStockMarket();
            initSymbolToStockMap();
        });

        it("should properly initialize", function() {

        });
    });

    describe("Transaction Cost Calculator Functions", function() {
        describe("getBuyTransactionCost()", function() {
            it("should fail on invalid 'stock' argument", function() {
                const res = getBuyTransactionCost({}, 10, PositionTypes.Long);
                expect(res).to.equal(null);
            });

            it("should fail on invalid 'shares' arg", function() {
                let res = getBuyTransactionCost(stock, NaN, PositionTypes.Long);
                expect(res).to.equal(null);

                res = getBuyTransactionCost(stock, -1, PositionTypes.Long);
                expect(res).to.equal(null);
            });

            it("should properly evaluate LONG transactions that doesn't trigger a price movement", function() {
                const shares = ctorParams.shareTxForMovement / 2;
                const res = getBuyTransactionCost(stock, shares, PositionTypes.Long);
                expect(res).to.equal(shares * stock.getAskPrice() + commission);
            });

            it("should properly evaluate SHORT transactions that doesn't trigger a price movement", function() {
                const shares = ctorParams.shareTxForMovement / 2;
                const res = getBuyTransactionCost(stock, shares, PositionTypes.Short);
                expect(res).to.equal(shares * stock.getBidPrice() + commission);
            });

            it("should properly evaluate LONG transactions that trigger price movements", function() {
                const sharesPerMvmt = ctorParams.shareTxForMovement;
                const shares = sharesPerMvmt * 3;
                const res = getBuyTransactionCost(stock, shares, PositionTypes.Long);

                // Calculate expected cost
                const secondPrice = stock.getAskPrice() * calculateIncreasingPriceMovement(stock);
                const thirdPrice = secondPrice * calculateIncreasingPriceMovement(stock);
                let expected = (sharesPerMvmt * stock.getAskPrice()) + (sharesPerMvmt * secondPrice) + (sharesPerMvmt * thirdPrice);

                expect(res).to.equal(expected + commission);
            });

            it("should properly evaluate SHORT transactions that trigger price movements", function() {
                const sharesPerMvmt = ctorParams.shareTxForMovement;
                const shares = sharesPerMvmt * 3;
                const res = getBuyTransactionCost(stock, shares, PositionTypes.Short);

                // Calculate expected cost
                const secondPrice = stock.getBidPrice() * calculateDecreasingPriceMovement(stock);
                const thirdPrice = secondPrice * calculateDecreasingPriceMovement(stock);
                let expected = (sharesPerMvmt * stock.getBidPrice()) + (sharesPerMvmt * secondPrice) + (sharesPerMvmt * thirdPrice);

                expect(res).to.equal(expected + commission);
            });

            it("should cap the 'shares' argument at the stock's maximum number of shares", function() {
                const maxRes = getBuyTransactionCost(stock, stock.maxShares, PositionTypes.Long);
                const exceedRes = getBuyTransactionCost(stock, stock.maxShares * 10, PositionTypes.Long);
                expect(maxRes).to.equal(exceedRes);
            });
        });

        describe("getSellTransactionGain()", function() {
            it("should fail on invalid 'stock' argument", function() {
                const res = getSellTransactionGain({}, 10, PositionTypes.Long);
                expect(res).to.equal(null);
            });

            it("should fail on invalid 'shares' arg", function() {
                let res = getSellTransactionGain(stock, NaN, PositionTypes.Long);
                expect(res).to.equal(null);

                res = getSellTransactionGain(stock, -1, PositionTypes.Long);
                expect(res).to.equal(null);
            });

            it("should properly evaluate LONG transactions that doesn't trigger a price movement", function() {
                const shares = ctorParams.shareTxForMovement / 2;
                const res = getSellTransactionGain(stock, shares, PositionTypes.Long);
                const expected = shares * stock.getBidPrice() - commission;
                expect(res).to.equal(expected);
            });

            it("should properly evaluate SHORT transactions that doesn't trigger a price movement", function() {
                // We need to set this property in order to calculate gains from short position
                stock.playerAvgShortPx = stock.price * 2;

                const shares = ctorParams.shareTxForMovement / 2;
                const res = getSellTransactionGain(stock, shares, PositionTypes.Short);
                const expected = (shares * stock.playerAvgShortPx) + (shares * (stock.playerAvgShortPx - stock.getAskPrice())) - commission;
                expect(res).to.equal(expected);
            });

            it("should properly evaluate LONG transactions that trigger price movements", function() {
                const sharesPerMvmt = ctorParams.shareTxForMovement;
                const shares = sharesPerMvmt * 3;
                const res = getSellTransactionGain(stock, shares, PositionTypes.Long);

                // Calculated expected gain
                const mvmt = calculateDecreasingPriceMovement(stock);
                const secondPrice = stock.getBidPrice() * mvmt;
                const thirdPrice = secondPrice * mvmt;
                const expected = (sharesPerMvmt * stock.getBidPrice()) + (sharesPerMvmt * secondPrice) + (sharesPerMvmt * thirdPrice);

                expect(res).to.equal(expected - commission);
            });

            it("should properly evaluate SHORT transactions that trigger price movements", function() {
                // We need to set this property in order to calculate gains from short position
                stock.playerAvgShortPx = stock.price * 2;

                const sharesPerMvmt = ctorParams.shareTxForMovement;
                const shares = sharesPerMvmt * 3;
                const res = getSellTransactionGain(stock, shares, PositionTypes.Short);

                // Calculate expected gain
                const mvmt = calculateIncreasingPriceMovement(stock);
                const secondPrice = stock.getAskPrice() * mvmt;
                const thirdPrice = secondPrice * mvmt;
                function getGainForPrice(thisPrice) {
                    const origCost = sharesPerMvmt * stock.playerAvgShortPx;
                    return origCost + ((stock.playerAvgShortPx - thisPrice) * sharesPerMvmt);
                }
                const expected = getGainForPrice(stock.getAskPrice()) + getGainForPrice(secondPrice) + getGainForPrice(thirdPrice);

                expect(res).to.equal(expected - commission);
            });

            it("should cap the 'shares' argument at the stock's maximum number of shares", function() {
                const maxRes = getSellTransactionGain(stock, stock.maxShares, PositionTypes.Long);
                const exceedRes = getSellTransactionGain(stock, stock.maxShares * 10, PositionTypes.Long);
                expect(maxRes).to.equal(exceedRes);
            });
        });
    });

    describe("Price Movement Processor Functions", function() {
        // N = 1 is the original price
        function getNthPriceIncreasing(origPrice, n) {
            let price = origPrice;
            for (let i = 1; i < n; ++i) {
                price *= calculateIncreasingPriceMovement(stock);
            }

            return price;
        }

        // N = 1 is the original price
        function getNthPriceDecreasing(origPrice, n) {
            let price = origPrice;
            for (let i = 1; i < n; ++i) {
                price *= calculateDecreasingPriceMovement(stock);
            }

            return price;
        }

        // N = 1 is the original forecast
        function getNthForecast(origForecast, n) {
            return origForecast - forecastChangePerPriceMovement * (n - 1);
        }

        describe("processBuyTransactionPriceMovement()", function() {
            const noMvmtShares = Math.round(ctorParams.shareTxForMovement / 2.2);
            const mvmtShares = ctorParams.shareTxForMovement * 3 + noMvmtShares;

            it("should do nothing on invalid 'stock' argument", function() {
                const oldPrice = stock.price;
                const oldTracker = stock.shareTxUntilMovement;

                processBuyTransactionPriceMovement({}, mvmtShares, PositionTypes.Long);
                expect(stock.price).to.equal(oldPrice);
                expect(stock.shareTxUntilMovement).to.equal(oldTracker);
            });

            it("should do nothing on invalid 'shares' arg", function() {
                const oldPrice = stock.price;
                const oldTracker = stock.shareTxUntilMovement;

                processBuyTransactionPriceMovement(stock, NaN, PositionTypes.Long);
                expect(stock.price).to.equal(oldPrice);
                expect(stock.shareTxUntilMovement).to.equal(oldTracker);

                processBuyTransactionPriceMovement(stock, -1, PositionTypes.Long);
                expect(stock.price).to.equal(oldPrice);
                expect(stock.shareTxUntilMovement).to.equal(oldTracker);
            });

            it("should properly evaluate a LONG transaction that doesn't trigger a price movement", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processBuyTransactionPriceMovement(stock, noMvmtShares, PositionTypes.Long);
                expect(stock.price).to.equal(oldPrice);
                expect(stock.otlkMag).to.equal(oldForecast);
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement - noMvmtShares);
            });

            it("should properly evaluate a SHORT transaction that doesn't trigger a price movement", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processBuyTransactionPriceMovement(stock, noMvmtShares, PositionTypes.Short);
                expect(stock.price).to.equal(oldPrice);
                expect(stock.otlkMag).to.equal(oldForecast);
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement - noMvmtShares);
            });

            it("should properly evaluate LONG transactions that trigger price movements", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processBuyTransactionPriceMovement(stock, mvmtShares, PositionTypes.Long);
                expect(stock.price).to.equal(getNthPriceIncreasing(oldPrice, 4));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 4));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement - noMvmtShares);
            });

            it("should properly evaluate SHORT transactions that trigger price movements", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processBuyTransactionPriceMovement(stock, mvmtShares, PositionTypes.Short);
                expect(stock.price).to.equal(getNthPriceDecreasing(oldPrice, 4));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 4));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement - noMvmtShares);
            });

            it("should properly evaluate LONG transactions of exactly 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processBuyTransactionPriceMovement(stock, stock.shareTxForMovement, PositionTypes.Long);
                expect(stock.price).to.equal(getNthPriceIncreasing(oldPrice, 2));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 2));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });

            it("should properly evaluate LONG transactions that total to 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processBuyTransactionPriceMovement(stock, Math.round(stock.shareTxForMovement / 2), PositionTypes.Long);
                processBuyTransactionPriceMovement(stock, stock.shareTxUntilMovement, PositionTypes.Long);
                expect(stock.price).to.equal(getNthPriceIncreasing(oldPrice, 2));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 2));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });

            it("should properly evaluate LONG transactions that are a multiple of 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processBuyTransactionPriceMovement(stock, 3 * stock.shareTxForMovement, PositionTypes.Long);
                expect(stock.price).to.equal(getNthPriceIncreasing(oldPrice, 4));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 4));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });

            it("should properly evaluate SHORT transactions of exactly 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processBuyTransactionPriceMovement(stock, stock.shareTxForMovement, PositionTypes.Short);
                expect(stock.price).to.equal(getNthPriceDecreasing(oldPrice, 2));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 2));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });

            it("should properly evaluate SHORT transactions that total to 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processBuyTransactionPriceMovement(stock, Math.round(stock.shareTxForMovement / 2), PositionTypes.Short);
                processBuyTransactionPriceMovement(stock, stock.shareTxUntilMovement, PositionTypes.Short);
                expect(stock.price).to.equal(getNthPriceDecreasing(oldPrice, 2));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 2));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });

            it("should properly evaluate SHORT transactions that are a multiple of 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processBuyTransactionPriceMovement(stock, 3 * stock.shareTxForMovement, PositionTypes.Short);
                expect(stock.price).to.equal(getNthPriceDecreasing(oldPrice, 4));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 4));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });
        });

        describe("processSellTransactionPriceMovement()", function() {
            const noMvmtShares = Math.round(ctorParams.shareTxForMovement / 2.2);
            const mvmtShares = ctorParams.shareTxForMovement * 3 + noMvmtShares;

            it("should do nothing on invalid 'stock' argument", function() {
                const oldPrice = stock.price;
                const oldTracker = stock.shareTxUntilMovement;

                processSellTransactionPriceMovement({}, mvmtShares, PositionTypes.Long);
                expect(stock.price).to.equal(oldPrice);
                expect(stock.shareTxUntilMovement).to.equal(oldTracker);
            });

            it("should do nothing on invalid 'shares' arg", function() {
                const oldPrice = stock.price;
                const oldTracker = stock.shareTxUntilMovement;

                processSellTransactionPriceMovement(stock, NaN, PositionTypes.Long);
                expect(stock.price).to.equal(oldPrice);
                expect(stock.shareTxUntilMovement).to.equal(oldTracker);

                processSellTransactionPriceMovement(stock, -1, PositionTypes.Long);
                expect(stock.price).to.equal(oldPrice);
                expect(stock.shareTxUntilMovement).to.equal(oldTracker);
            });

            it("should properly evaluate a LONG transaction that doesn't trigger a price movement", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processSellTransactionPriceMovement(stock, noMvmtShares, PositionTypes.Long);
                expect(stock.price).to.equal(oldPrice);
                expect(stock.otlkMag).to.equal(oldForecast);
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement - noMvmtShares);
            });

            it("should properly evaluate a SHORT transaction that doesn't trigger a price movement", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processSellTransactionPriceMovement(stock, noMvmtShares, PositionTypes.Short);
                expect(stock.price).to.equal(oldPrice);
                expect(stock.otlkMag).to.equal(oldForecast);
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement - noMvmtShares);
            });

            it("should properly evaluate LONG transactions that trigger price movements", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processSellTransactionPriceMovement(stock, mvmtShares, PositionTypes.Long);
                expect(stock.price).to.equal(getNthPriceDecreasing(oldPrice, 4));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 4));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement - noMvmtShares);
            });

            it("should properly evaluate SHORT transactions that trigger price movements", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processSellTransactionPriceMovement(stock, mvmtShares, PositionTypes.Short);
                expect(stock.price).to.equal(getNthPriceIncreasing(oldPrice, 4));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 4));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement - noMvmtShares);
            });

            it("should properly evaluate LONG transactions of exactly 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processSellTransactionPriceMovement(stock, stock.shareTxForMovement, PositionTypes.Long);
                expect(stock.price).to.equal(getNthPriceDecreasing(oldPrice, 2));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 2));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });

            it("should properly evaluate LONG transactions that total to 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processSellTransactionPriceMovement(stock, Math.round(stock.shareTxForMovement / 2), PositionTypes.Long);
                processSellTransactionPriceMovement(stock, stock.shareTxUntilMovement, PositionTypes.Long);
                expect(stock.price).to.equal(getNthPriceDecreasing(oldPrice, 2));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 2));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });

            it("should properly evaluate LONG transactions that are a multiple of 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processSellTransactionPriceMovement(stock, 3 * stock.shareTxForMovement, PositionTypes.Long);
                expect(stock.price).to.equal(getNthPriceDecreasing(oldPrice, 4));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 4));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });

            it("should properly evaluate SHORT transactions of exactly 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processSellTransactionPriceMovement(stock, stock.shareTxForMovement, PositionTypes.Short);
                expect(stock.price).to.equal(getNthPriceIncreasing(oldPrice, 2));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 2));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });

            it("should properly evaluate SHORT transactions that total to 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processSellTransactionPriceMovement(stock, Math.round(stock.shareTxForMovement / 2), PositionTypes.Short);
                processSellTransactionPriceMovement(stock, stock.shareTxUntilMovement, PositionTypes.Short);
                expect(stock.price).to.equal(getNthPriceIncreasing(oldPrice, 2));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 2));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });

            it("should properly evaluate SHORT transactions that are a multiple of 'shareTxForMovement' shares", function() {
                const oldPrice = stock.price;
                const oldForecast = stock.otlkMag;

                processSellTransactionPriceMovement(stock, 3 * stock.shareTxForMovement, PositionTypes.Short);
                expect(stock.price).to.equal(getNthPriceIncreasing(oldPrice, 4));
                expect(stock.otlkMag).to.equal(getNthForecast(oldForecast, 4));
                expect(stock.shareTxUntilMovement).to.equal(stock.shareTxForMovement);
            });
        });
    });

    describe("Order Class", function() {
        it("should throw on invalid arguments", function() {
            function invalid1() {
                return new Order({}, 1, 1, OrderTypes.LimitBuy, PositionTypes.Long);
            }
            function invalid2() {
                return new Order("FOO", "z", 0, OrderTypes.LimitBuy, PositionTypes.Short);
            }
            function invalid3() {
                return new Order("FOO", 1, {}, OrderTypes.LimitBuy, PositionTypes.Short);
            }
            function invalid4() {
                return new Order("FOO", 1, NaN, OrderTypes.LimitBuy, PositionTypes.Short);
            }
            function invalid5() {
                return new Order("FOO", NaN, 0, OrderTypes.LimitBuy, PositionTypes.Short);
            }

            expect(invalid1).to.throw();
            expect(invalid2).to.throw();
            expect(invalid3).to.throw();
            expect(invalid4).to.throw();
            expect(invalid5).to.throw();
        });
    });

    describe("Order Processing", function() {

    });
});