From 0a8c07cc0773a1e3c109a3ccfa8b95896b7d75a8 Mon Sep 17 00:00:00 2001 From: Jesse Plamondon-Willard Date: Sun, 18 Jun 2017 20:24:32 -0400 Subject: [PATCH] simplify date operators by making SDate.GetHashCode() return unique ordered values, expand unit tests (#307) --- src/StardewModdingAPI.Tests/SDateTests.cs | 180 +++++++++++++++++----- src/StardewModdingAPI/Utilities/SDate.cs | 180 +++++++--------------- 2 files changed, 196 insertions(+), 164 deletions(-) diff --git a/src/StardewModdingAPI.Tests/SDateTests.cs b/src/StardewModdingAPI.Tests/SDateTests.cs index 1cce6335..fa898918 100644 --- a/src/StardewModdingAPI.Tests/SDateTests.cs +++ b/src/StardewModdingAPI.Tests/SDateTests.cs @@ -1,4 +1,5 @@ using System; +using System.Collections.Generic; using System.Diagnostics.CodeAnalysis; using System.Linq; using System.Text.RegularExpressions; @@ -15,10 +16,35 @@ namespace StardewModdingAPI.Tests ** Properties *********/ /// All valid seasons. - private static string[] ValidSeasons = { "spring", "summer", "fall", "winter" }; + private static readonly string[] ValidSeasons = { "spring", "summer", "fall", "winter" }; /// All valid days of a month. - private static int[] ValidDays = Enumerable.Range(1, 28).ToArray(); + private static readonly int[] ValidDays = Enumerable.Range(1, 28).ToArray(); + + /// Sample relative dates for test cases. + private static class Dates + { + /// The base date to which other dates are relative. + public const string Now = "02 summer Y2"; + + /// The day before . + public const string PrevDay = "01 summer Y2"; + + /// The month before . + public const string PrevMonth = "02 spring Y2"; + + /// The year before . + public const string PrevYear = "02 summer Y1"; + + /// The day after . + public const string NextDay = "03 summer Y2"; + + /// The month after . + public const string NextMonth = "02 fall Y2"; + + /// The year after . + public const string NextYear = "02 summer Y3"; + } /********* @@ -63,7 +89,7 @@ namespace StardewModdingAPI.Tests [TestCase("01 winter Y1", ExpectedResult = "01 winter Y1")] public string ToString(string dateStr) { - return this.ParseDate(dateStr).ToString(); + return this.GetDate(dateStr).ToString(); } /**** @@ -80,58 +106,132 @@ namespace StardewModdingAPI.Tests [TestCase("01 spring Y3", -(28 * 7 + 17), ExpectedResult = "12 spring Y1")] // negative year transition public string AddDays(string dateStr, int addDays) { - return this.ParseDate(dateStr).AddDays(addDays).ToString(); + return this.GetDate(dateStr).AddDays(addDays).ToString(); } - [Test(Description = "Assert that the equality operators work as expected")] - public void EqualityOperators() + /**** + ** GetHashCode + ****/ + [Test(Description = "Assert that GetHashCode returns a unique ordered value for every date.")] + public void GetHashCode_ReturnsUniqueOrderedValue() { - SDate s1 = new SDate(1, "spring", 2); - SDate s2 = new SDate(1, "spring", 2); - SDate s3 = new SDate(1, "spring", 3); - SDate s4 = new SDate(12, "spring", 2); - SDate s5 = new SDate(1, "summer", 2); + IDictionary hashes = new Dictionary(); + int lastHash = int.MinValue; + for (int year = 1; year <= 4; year++) + { + foreach (string season in SDateTests.ValidSeasons) + { + foreach (int day in SDateTests.ValidDays) + { + SDate date = new SDate(day, season, year); + int hash = date.GetHashCode(); + if (hashes.TryGetValue(hash, out SDate otherDate)) + Assert.Fail($"Received identical hash code {hash} for dates {otherDate} and {date}."); + if (hash < lastHash) + Assert.Fail($"Received smaller hash code for date {date} ({hash}) relative to {hashes[lastHash]} ({lastHash})."); - Assert.AreEqual(true, s1 == s2); - Assert.AreNotEqual(true, s1 == s3); - Assert.AreNotEqual(true, s1 == s4); - Assert.AreNotEqual(true, s1 == s5); + lastHash = hash; + hashes[hash] = date; + } + } + } } - [Test(Description = "Assert that the comparison operators work as expected")] - public void ComparisonOperators() + [Test(Description = "Assert that the == operator returns the expected values. We only need a few test cases, since it's based on GetHashCode which is tested more thoroughly.")] + [TestCase(Dates.Now, null, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevDay, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevMonth, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevYear, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.Now, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.NextDay, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.NextMonth, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.NextYear, ExpectedResult = false)] + public bool Operators_Equals(string now, string other) { - SDate s1 = new SDate(1, "spring", 2); - SDate s2 = new SDate(1, "spring", 2); - SDate s3 = new SDate(1, "spring", 3); - SDate s4 = new SDate(12, "spring", 2); - SDate s5 = new SDate(1, "summer", 2); - SDate s6 = new SDate(1, "winter", 1); - SDate s7 = new SDate(13, "fall", 1); - - Assert.AreEqual(true, s1 <= s2); - Assert.AreEqual(true, s1 >= s2); - Assert.AreEqual(true, s1 < s4); - Assert.AreEqual(true, s1 <= s4); - Assert.AreEqual(true, s4 > s1); - Assert.AreEqual(true, s4 >= s1); - Assert.AreEqual(true, s5 > s7); - Assert.AreEqual(true, s5 >= s7); - Assert.AreEqual(true, s6 < s5); - Assert.AreEqual(true, s6 <= s5); - Assert.AreEqual(true, s1 < s5); - Assert.AreEqual(true, s1 <= s5); - Assert.AreEqual(true, s5 > s1); - Assert.AreEqual(true, s5 >= s1); + return this.GetDate(now) == this.GetDate(other); } + [Test(Description = "Assert that the != operator returns the expected values. We only need a few test cases, since it's based on GetHashCode which is tested more thoroughly.")] + [TestCase(Dates.Now, null, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.PrevDay, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.PrevMonth, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.PrevYear, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.Now, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.NextDay, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.NextMonth, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.NextYear, ExpectedResult = true)] + public bool Operators_NotEquals(string now, string other) + { + return this.GetDate(now) != this.GetDate(other); + } + + [Test(Description = "Assert that the < operator returns the expected values. We only need a few test cases, since it's based on GetHashCode which is tested more thoroughly.")] + [TestCase(Dates.Now, null, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevDay, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevMonth, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevYear, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.Now, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.NextDay, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.NextMonth, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.NextYear, ExpectedResult = true)] + public bool Operators_LessThan(string now, string other) + { + return this.GetDate(now) < this.GetDate(other); + } + + [Test(Description = "Assert that the <= operator returns the expected values. We only need a few test cases, since it's based on GetHashCode which is tested more thoroughly.")] + [TestCase(Dates.Now, null, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevDay, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevMonth, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevYear, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.Now, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.NextDay, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.NextMonth, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.NextYear, ExpectedResult = true)] + public bool Operators_LessThanOrEqual(string now, string other) + { + return this.GetDate(now) <= this.GetDate(other); + } + + [Test(Description = "Assert that the > operator returns the expected values. We only need a few test cases, since it's based on GetHashCode which is tested more thoroughly.")] + [TestCase(Dates.Now, null, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevDay, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.PrevMonth, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.PrevYear, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.Now, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.NextDay, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.NextMonth, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.NextYear, ExpectedResult = false)] + public bool Operators_MoreThan(string now, string other) + { + return this.GetDate(now) > this.GetDate(other); + } + + [Test(Description = "Assert that the > operator returns the expected values. We only need a few test cases, since it's based on GetHashCode which is tested more thoroughly.")] + [TestCase(Dates.Now, null, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.PrevDay, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.PrevMonth, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.PrevYear, ExpectedResult = true)] + [TestCase(Dates.Now, Dates.Now, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.NextDay, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.NextMonth, ExpectedResult = false)] + [TestCase(Dates.Now, Dates.NextYear, ExpectedResult = false)] + public bool Operators_MoreThanOrEqual(string now, string other) + { + return this.GetDate(now) > this.GetDate(other); + } + + /********* ** Private methods *********/ /// Convert a string date into a game date, to make unit tests easier to read. /// The date string like "dd MMMM yy". - private SDate ParseDate(string dateStr) + private SDate GetDate(string dateStr) { + if (dateStr == null) + return null; + void Fail(string reason) => throw new AssertionException($"Couldn't parse date '{dateStr}' because {reason}."); // parse diff --git a/src/StardewModdingAPI/Utilities/SDate.cs b/src/StardewModdingAPI/Utilities/SDate.cs index fdeffe80..5f7ff030 100644 --- a/src/StardewModdingAPI/Utilities/SDate.cs +++ b/src/StardewModdingAPI/Utilities/SDate.cs @@ -13,6 +13,9 @@ namespace StardewModdingAPI.Utilities /// The internal season names in order. private readonly string[] Seasons = { "spring", "summer", "fall", "winter" }; + /// The number of seasons in a year. + private int SeasonsInYear => this.Seasons.Length; + /// The number of days in a season. private readonly int DaysInSeason = 28; @@ -77,10 +80,8 @@ namespace StardewModdingAPI.Utilities // handle season transition if (day > this.DaysInSeason || day < 1) { - // get current season index - int curSeasonIndex = Array.IndexOf(this.Seasons, this.Season); - if (curSeasonIndex == -1) - throw new InvalidOperationException($"The current season '{this.Season}' wasn't recognised."); + // get season index + int curSeasonIndex = this.GetSeasonIndex(); // get season offset int seasonOffset = day / this.DaysInSeason; @@ -94,7 +95,7 @@ namespace StardewModdingAPI.Utilities } // validate - if(year < 1) + if (year < 1) throw new ArithmeticException($"Adding {offset} days to {this} would result in invalid date {day:00} {season} {year}."); // return new date @@ -116,157 +117,88 @@ namespace StardewModdingAPI.Utilities /********* ** Operator methods *********/ - - /// - /// Equality operator. Tests the date being equal to each other - /// - /// The first date being compared - /// The second date being compared + /// Get whether one date is equal to another. + /// The base date to compare. + /// The other date to compare. /// The equality of the dates - public static bool operator ==(SDate s1, SDate s2) + public static bool operator ==(SDate date, SDate other) { - if (s1.Day == s2.Day && s1.Year == s2.Year && s1.Season == s2.Season) - return true; - else - return false; + return date?.GetHashCode() == other?.GetHashCode(); } - /// - /// Inequality operator. Tests the date being not equal to each other - /// - /// The first date being compared - /// The second date being compared - /// The inequality of the dates - public static bool operator !=(SDate s1, SDate s2) + /// Get whether one date is not equal to another. + /// The base date to compare. + /// The other date to compare. + public static bool operator !=(SDate date, SDate other) { - if (s1.Day == s2.Day && s1.Year == s2.Year && s1.Season == s2.Season) - return false; - else - return true; + return date?.GetHashCode() != other?.GetHashCode(); } - /// - /// Less than operator. Tests the date being less than to each other - /// - /// The first date being compared - /// The second date being compared - /// If the dates are less than - public static bool operator >(SDate s1, SDate s2) + /// Get whether one date is more than another. + /// The base date to compare. + /// The other date to compare. + public static bool operator >(SDate date, SDate other) { - if (s1.Year > s2.Year) - return true; - else if (s1.Year == s2.Year) - { - if (s1.Season == "winter" && s2.Season != "winter") - return true; - else if (s1.Season == s2.Season && s1.Day > s2.Day) - return true; - if (s1.Season == "fall" && (s2.Season == "summer" || s2.Season == "spring")) - return true; - if (s1.Season == "summer" && s2.Season == "spring") - return true; - } - - return false; + return date?.GetHashCode() > other?.GetHashCode(); } - /// - /// Less or equal than operator. Tests the date being less than or equal to each other - /// - /// The first date being compared - /// The second date being compared - /// If the dates are less than or equal than - public static bool operator >=(SDate s1, SDate s2) + /// Get whether one date is more than or equal to another. + /// The base date to compare. + /// The other date to compare. + public static bool operator >=(SDate date, SDate other) { - if (s1.Year > s2.Year) - return true; - else if (s1.Year == s2.Year) - { - if (s1.Season == "winter" && s2.Season != "winter") - return true; - else if (s1.Season == s2.Season && s1.Day >= s2.Day) - return true; - if (s1.Season == "fall" && (s2.Season == "summer" || s2.Season == "spring")) - return true; - if (s1.Season == "summer" && s2.Season == "spring") - return true; - } - - return false; + return date?.GetHashCode() >= other?.GetHashCode(); } - /// - /// Greater or equal than operator. Tests the date being greater than or equal to each other - /// - /// The first date being compared - /// The second date being compared - /// If the dates are greater than or equal than - public static bool operator <=(SDate s1, SDate s2) + /// Get whether one date is less than or equal to another. + /// The base date to compare. + /// The other date to compare. + public static bool operator <=(SDate date, SDate other) { - if (s1.Year < s2.Year) - return true; - else if (s1.Year == s2.Year) - { - if (s1.Season == s2.Season && s1.Day <= s2.Day) - return true; - else if (s1.Season == "spring" && s2.Season != "spring") - return true; - if (s1.Season == "summer" && (s2.Season == "fall" || s2.Season == "winter")) - return true; - if (s1.Season == "fall" && s2.Season == "winter") - return true; - } - - return false; + return date?.GetHashCode() <= other?.GetHashCode(); } - /// - /// Greater than operator. Tests the date being greater than to each other - /// - /// The first date being compared - /// The second date being compared - /// If the dates are greater than - public static bool operator <(SDate s1, SDate s2) + /// Get whether one date is less than another. + /// The base date to compare. + /// The other date to compare. + public static bool operator <(SDate date, SDate other) { - if (s1.Year < s2.Year) - return true; - else if (s1.Year == s2.Year) - { - if (s1.Season == s2.Season && s1.Day < s2.Day) - return true; - else if (s1.Season == "spring" && s2.Season != "spring") - return true; - if (s1.Season == "summer" && (s2.Season == "fall" || s2.Season == "winter")) - return true; - if (s1.Season == "fall" && s2.Season == "winter") - return true; - } - - return false; + return date?.GetHashCode() < other?.GetHashCode(); } - /// - /// Overrides the equals function. - /// + /// Overrides the equals function. /// Object being compared. /// The equalaity of the object. public override bool Equals(object obj) { - return base.Equals(obj); + return obj is SDate other && this == other; } - /// - /// This returns the hashcode of the object - /// - /// The hashcode of the object. + /// Get a hash code which uniquely identifies a date. public override int GetHashCode() { - return base.GetHashCode(); + // return the number of days since 01 spring Y1 + int yearIndex = this.Year - 1; + return + yearIndex * this.DaysInSeason * this.SeasonsInYear + + this.GetSeasonIndex() * this.DaysInSeason + + this.Day; } + /********* ** Private methods *********/ + /// Get the current season index. + /// The current season wasn't recognised. + private int GetSeasonIndex() + { + int index = Array.IndexOf(this.Seasons, this.Season); + if (index == -1) + throw new InvalidOperationException($"The current season '{this.Season}' wasn't recognised."); + return index; + } + /// Get the real index in an array which should be treated as a two-way loop. /// The index in the looped array. /// The number of elements in the array.