WIP Apply nullability

AdventOfCode.Common/AdventOfCode.Common.csproj

@@ -3,8 +3,8 @@
     <PropertyGroup>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
-        <RootNamespace>AdventOfCode.Common</RootNamespace>
         <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode.Common</RootNamespace>
     </PropertyGroup>
 
 </Project>

AdventOfCode2017.Tests/AdventOfCode2017.Tests.csproj

@@ -3,9 +3,11 @@
     <PropertyGroup>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
         <RootNamespace>AdventOfCode2017.Tests</RootNamespace>
 
         <IsPackable>false</IsPackable>
+        <IsTestProject>true</IsTestProject>
     </PropertyGroup>
 
     <ItemGroup>

AdventOfCode2017/AdventOfCode2017.csproj

@@ -4,6 +4,7 @@
         <OutputType>Exe</OutputType>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
         <RootNamespace>AdventOfCode2017</RootNamespace>
     </PropertyGroup>
 

AdventOfCode2017/Day03.cs

@@ -30,11 +30,11 @@ public class Day03 : IDay
 {
     public string ResolvePart1(string[] inputs)
     {
-        return null;
+        return string.Empty;
     }
 
     public string ResolvePart2(string[] inputs)
     {
-        return null;
+        return string.Empty;
     }
 }

AdventOfCode2018.Tests/AdventOfCode2018.Tests.csproj

@@ -3,9 +3,11 @@
     <PropertyGroup>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
         <RootNamespace>AdventOfCode2018.Tests</RootNamespace>
 
         <IsPackable>false</IsPackable>
+        <IsTestProject>true</IsTestProject>
     </PropertyGroup>
 
     <ItemGroup>

AdventOfCode2018/AdventOfCode2018.csproj

@@ -4,6 +4,7 @@
         <OutputType>Exe</OutputType>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
         <RootNamespace>AdventOfCode2018</RootNamespace>
     </PropertyGroup>
 

AdventOfCode2018/Day01.cs

@@ -82,7 +82,7 @@ public class Day01 : IDay
     public string ResolvePart2(string[] inputs)
     {
         int accumulator = 0;
-        List<int> accumulatorHistory = new();
+        List<int> accumulatorHistory = [];
         int? repeatedAccumulator = null;
         while (repeatedAccumulator == null)
         {
@@ -108,6 +108,6 @@ public class Day01 : IDay
                 }
             }
         }
-        return repeatedAccumulator.ToString();
+        return repeatedAccumulator.ToString() ?? string.Empty;
     }
 }

AdventOfCode2018/Day03.cs

@@ -94,7 +94,7 @@ public class Day03 : IDay
     {
         List<Claim> claims = inputs.Select(Claim.FromString).ToList();
 
-        Claim unOverlappingClaim = null;
+        Claim? unOverlappingClaim = null;
         for (int i = 0; i < claims.Count; i++)
         {
             bool overlaps = false;
@@ -113,7 +113,7 @@ public class Day03 : IDay
                 break;
             }
         }
-        return unOverlappingClaim.ID.ToString();
+        return unOverlappingClaim?.ID.ToString() ?? string.Empty;
 
     }
 

AdventOfCode2018/Day04.cs

@@ -71,7 +71,7 @@ public class Day04 : IDay
         Dictionary<int, GuardSleepHistogram> dictFullHistogram = BuildFullHistogram(guardEvents);
 
         // Find sleepier guard
-        GuardSleepHistogram highestSleeperHistogram = null;
+        GuardSleepHistogram? highestSleeperHistogram = null;
         long highestTotalSleep = long.MinValue;
         foreach (GuardSleepHistogram guardHistogram in dictFullHistogram.Values)
         {
@@ -83,6 +83,7 @@ public class Day04 : IDay
                 highestTotalSleep = totalSleep;
             }
         }
+        if (highestSleeperHistogram == null) { return string.Empty; }
 
         // Find sleepier minute
         int maxSleepMinute = int.MinValue;

AdventOfCode2018/Day06.cs

@@ -97,6 +97,7 @@ public class Day06 : IDay
         return inputs
             .Where(input => string.IsNullOrEmpty(input) == false)
             .Select(ChronoPoint.FromString)
+            .OfType<ChronoPoint>()
             .ToList();
     }
 
@@ -197,7 +198,7 @@ public class Day06 : IDay
         public int X { get; set; }
         public int Y { get; set; }
 
-        public static ChronoPoint FromString(string strPoint)
+        public static ChronoPoint? FromString(string strPoint)
         {
             if (string.IsNullOrEmpty(strPoint)) { return null; }
             string[] parts = strPoint.Split([", "], StringSplitOptions.RemoveEmptyEntries);

AdventOfCode2018/Day07.cs

@@ -204,7 +204,7 @@ public class Day07 : IDay
 
         private class SimulatedWorker
         {
-            public InstructionNode CurrentInstruction { get; private set; }
+            public InstructionNode? CurrentInstruction { get; private set; }
             private int ElapsedTime { get; set; }
 
             public void SetInstruction(InstructionNode instruction)

AdventOfCode2018/Day09.cs

@@ -87,16 +87,16 @@ public class Day09 : IDay
     public class Marble
     {
         public long Value { get; init; }
-        public Marble Previous { get; set; }
+        public Marble? Previous { get; set; }
-        public Marble Next { get; set; }
+        public Marble? Next { get; set; }
     }
 
     public class MarbleGame
     {
         private Dictionary<long, long> Scores { get; } = new();
 
-        private Marble _firstMarble;
+        private Marble? _firstMarble;
-        private Marble _currentMarble;
+        private Marble? _currentMarble;
         private long _currentPlayer;
 
         private const long PointValueMultiple = 23;
@@ -119,8 +119,8 @@ public class Day09 : IDay
                 Marble newMarble = new() { Value = i + 1 };
                 if ((newMarble.Value % PointValueMultiple) > 0)
                 {
-                    Marble previousMarble = _currentMarble.Next;
+                    Marble? previousMarble = _currentMarble?.Next;
-                    Marble nextMarble = previousMarble.Next;
+                    Marble? nextMarble = previousMarble?.Next;
                     newMarble.Previous = previousMarble;
                     newMarble.Next = nextMarble;
                     previousMarble.Next = newMarble;
@@ -129,7 +129,7 @@ public class Day09 : IDay
                 }
                 else
                 {
-                    Marble marbleToRemove = _currentMarble.Previous.Previous.Previous.Previous.Previous.Previous.Previous;
+                    Marble? marbleToRemove = _currentMarble?.Previous?.Previous?.Previous?.Previous?.Previous?.Previous?.Previous;
                     _currentMarble = marbleToRemove.Next;
                     marbleToRemove.Previous.Next = marbleToRemove.Next;
                     marbleToRemove.Next.Previous = marbleToRemove.Previous;

AdventOfCode2018/Day12.cs

@@ -111,8 +111,8 @@ public class Day12 : IDay
     private readonly List<bool> _initialState = [];
     private readonly List<PlantRule> _rules = [];
     private long _offsetField;
-    private bool[] _field;
+    private bool[]? _field;
-    private bool[] _workField;
+    private bool[]? _workField;
 
     private void Initialize(string[] inputs)
     {

AdventOfCode2018/Day13.cs

@@ -371,7 +371,7 @@ public class Day13 : IDay
 
     private int _width;
     private int _height;
-    private char[,] _grid;
+    private char[,]? _grid;
     private readonly List<Train> _trains = [];
 
     private void Initialize(string[] inputs)
@@ -430,9 +430,9 @@ public class Day13 : IDay
         }
     }
 
-    private Train SimulateForFirstCollision()
+    private Train? SimulateForFirstCollision()
     {
-        Train collidingTrain = null;
+        Train? collidingTrain = null;
         IEnumerable<Train> orderedTrains = _trains.OrderBy(t => t.X + (t.Y * _width));
         foreach (Train t in orderedTrains)
         {
@@ -443,13 +443,13 @@ public class Day13 : IDay
         return collidingTrain;
     }
 
-    private Train SimulateForLastCart()
+    private Train? SimulateForLastCart()
     {
         List<Train> orderedTrains = _trains.OrderBy(t => t.X + (t.Y * _width)).ToList();
         foreach (Train t in orderedTrains)
         {
             t.Simulate(_grid);
-            Train collidingTrain = _trains.FirstOrDefault(x => x.X == t.X && x.Y == t.Y && t != x);
+            Train? collidingTrain = _trains.FirstOrDefault(x => x.X == t.X && x.Y == t.Y && t != x);
             if (collidingTrain != null)
             {
                 _trains.Remove(t);
@@ -470,7 +470,7 @@ public class Day13 : IDay
         {
             for (int i = 0; i < _width; i++)
             {
-                Train t = _trains.FirstOrDefault(x => x.X == i && x.Y == j);
+                Train? t = _trains.FirstOrDefault(x => x.X == i && x.Y == j);
                 if (t != null)
                 {
                     if (t.Direction == TrainDirection.North)

AdventOfCode2018/Day15.cs

@@ -509,7 +509,7 @@ public class Day15 : IDay
             .ThenBy(e => e.X);
     }
 
-    private Entity GetBestInRangeTarget(Entity entity, IEnumerable<Entity> targets)
+    private Entity? GetBestInRangeTarget(Entity entity, IEnumerable<Entity> targets)
     {
         return targets
             .Where(entity.InRangeOf)

AdventOfCode2018/Day16.cs

@@ -87,8 +87,8 @@ public class Day16 : IDay
         int count = 0;
         int i = 0;
         bool end = false;
-        int[] beforeRegisters = null;
+        int[]? beforeRegisters = null;
-        int[] instruction = null;
+        int[]? instruction = null;
         const string beforeKeyword = "Before: [";
         const string afterKeyword = "After:  [";
         while (inputs.Length > i)

AdventOfCode2018/Day23.cs

@@ -68,8 +68,8 @@ public class Day23 : IDay
     public string ResolvePart1(string[] inputs)
     {
         List<NanoBot> nanoBots = NanoBot.ListFromStrings(inputs);
-        NanoBot bestNanoBot = nanoBots.OrderBy(nanoBot => nanoBot.Range).LastOrDefault();
+        NanoBot? bestNanoBot = nanoBots.OrderBy(nanoBot => nanoBot.Range).LastOrDefault();
-        int countInRange = nanoBots.Count(nanoBot => bestNanoBot.InRange(nanoBot));
+        int countInRange = nanoBots.Count(nanoBot => bestNanoBot?.InRange(nanoBot) == true);
         return countInRange.ToString();
     }
 
@@ -150,7 +150,7 @@ public class Day23 : IDay
         public long Z { get; private init; }
         public long Range { get; private init; }
 
-        private static NanoBot FromString(string strInput)
+        private static NanoBot? FromString(string strInput)
         {
             string[] parts = strInput.Split(["pos=<", ",", ">, r="], StringSplitOptions.RemoveEmptyEntries);
             if (parts.Length != 4) { return null; }
@@ -167,7 +167,7 @@ public class Day23 : IDay
         {
             List<NanoBot> nanoBots = inputs
                 .Select(FromString)
-                .Where(nanoBot => nanoBot != null)
+                .OfType<NanoBot>()
                 .ToList();
             return nanoBots;
         }

AdventOfCode2020.Tests/AdventOfCode2020.Tests.csproj

@@ -3,9 +3,11 @@
     <PropertyGroup>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
         <RootNamespace>AdventOfCode2020.Tests</RootNamespace>
 
         <IsPackable>false</IsPackable>
+        <IsTestProject>true</IsTestProject>
     </PropertyGroup>
 
     <ItemGroup>

AdventOfCode2020/AdventOfCode2020.csproj

@@ -4,6 +4,7 @@
         <OutputType>Exe</OutputType>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
         <RootNamespace>AdventOfCode2020</RootNamespace>
     </PropertyGroup>
 

AdventOfCode2020/Day05.cs

@@ -64,7 +64,7 @@ public class Day05 : IDay
         int maxSerialNumber = 0;
         foreach (string input in inputs)
         {
-            Seat seat = Seat_Parse(input);
+            Seat? seat = Seat_Parse(input);
             if (seat == null) { continue; }
             int newSerialNumber = seat.GetSerialNumber();
             if (newSerialNumber > maxSerialNumber) { maxSerialNumber = newSerialNumber; }
@@ -83,7 +83,7 @@ public class Day05 : IDay
         }
         foreach (string input in inputs)
         {
-            Seat seat = Seat_Parse(input);
+            Seat? seat = Seat_Parse(input);
             if (seat == null) { continue; }
 
             seats[seat.Column][seat.Row] = 'X';
@@ -166,7 +166,7 @@ public class Day05 : IDay
         }
     }
 
-    private Seat Seat_Parse(string input)
+    private Seat? Seat_Parse(string input)
     {
         if (input.Length != 10 ||
             input.All(c => c == 'F' || c == 'B' || c == 'L' || c == 'R') == false

AdventOfCode2020/Day07.cs

@@ -141,7 +141,7 @@ public class Day07 : IDay
         BaggageRule rule = new() {
             Contain = [],
         };
-        BaggageContainRule containRule = null;
+        BaggageContainRule? containRule = null;
         string color1 = string.Empty;
 
         foreach (string word in words)

AdventOfCode2023.Tests/AdventOfCode2023.Tests.csproj

@@ -3,10 +3,11 @@
     <PropertyGroup>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
-        <RootNamespace>AdventOfCode2023.Tests</RootNamespace>
         <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode2023.Tests</RootNamespace>
 
         <IsPackable>false</IsPackable>
+        <IsTestProject>true</IsTestProject>
     </PropertyGroup>
 
     <ItemGroup>

AdventOfCode2023/AdventOfCode2023.csproj

@@ -4,8 +4,8 @@
         <OutputType>Exe</OutputType>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
-        <RootNamespace>AdventOfCode2023</RootNamespace>
         <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode2023</RootNamespace>
     </PropertyGroup>
 
     <ItemGroup>

AdventOfCode2024.Tests/AdventOfCode2024.Tests.csproj

@@ -3,8 +3,8 @@
     <PropertyGroup>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
-        <RootNamespace>AdventOfCode2024.Tests</RootNamespace>
         <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode2024.Tests</RootNamespace>
 
         <IsPackable>false</IsPackable>
         <IsTestProject>true</IsTestProject>
@@ -17,10 +17,6 @@
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
             <PrivateAssets>all</PrivateAssets>
         </PackageReference>
-        <PackageReference Include="coverlet.collector" Version="6.0.0">
-            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-            <PrivateAssets>all</PrivateAssets>
-        </PackageReference>
     </ItemGroup>
 
     <ItemGroup>

AdventOfCode2024/AdventOfCode2024.csproj

@@ -4,8 +4,8 @@
         <OutputType>Exe</OutputType>
         <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
-        <RootNamespace>AdventOfCode2024</RootNamespace>
         <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode2024</RootNamespace>
     </PropertyGroup>
 
     <ItemGroup>