restructure project to add unit testing

.drone.yml

@@ -6,4 +6,4 @@ steps:
     - name: run
       image: mcr.microsoft.com/dotnet/sdk:latest
       commands:
-          - dotnet run
+          - dotnet test

aoc.tests/Day1Test.cs

@@ -0,0 +1,29 @@
+using aoc2020;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace aoc.tests
+{
+    [TestClass]
+    public class Day1Test
+    {
+        private Day1 _day1;
+
+        [TestInitialize]
+        public void Initialize()
+        {
+            _day1 = new Day1();
+        }
+
+        [TestMethod]
+        public void TestPart1()
+        {
+            Assert.AreEqual("751776", _day1.Part1());
+        }
+
+        [TestMethod]
+        public void TestPart2()
+        {
+            Assert.AreEqual("42275090", _day1.Part2());
+        }
+    }
+}

aoc.tests/Day2Test.cs

@@ -0,0 +1,29 @@
+using aoc2020;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace aoc.tests
+{
+    [TestClass]
+    public class Day2Test
+    {
+        private Day2 _day2;
+
+        [TestInitialize]
+        public void Initialize()
+        {
+            _day2 = new Day2();
+        }
+
+        [TestMethod]
+        public void TestPart1()
+        {
+            Assert.AreEqual("556", _day2.Part1());
+        }
+
+        [TestMethod]
+        public void TestPart2()
+        {
+            Assert.AreEqual("605", _day2.Part2());
+        }
+    }
+}

aoc.tests/aoc.tests.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net5.0</TargetFramework>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
+    <PackageReference Include="MSTest.TestAdapter" Version="2.1.1" />
+    <PackageReference Include="MSTest.TestFramework" Version="2.1.1" />
+    <PackageReference Include="coverlet.collector" Version="1.3.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\aoc2020\aoc2020.csproj" />
+  </ItemGroup>
+
+</Project>

aoc2020.sln

@@ -3,7 +3,9 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 16
 VisualStudioVersion = 16.0.30709.132
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "aoc2020", "aoc2020.csproj", "{3D60F1A0-0DD9-4FF9-B85B-D491B13ACAE7}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "aoc2020", "aoc2020\aoc2020.csproj", "{3D60F1A0-0DD9-4FF9-B85B-D491B13ACAE7}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "aoc.tests", "aoc.tests\aoc.tests.csproj", "{4E841B34-CF2F-4751-B31D-8E1D5FCEC8F6}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -15,6 +17,10 @@ Global
 		{3D60F1A0-0DD9-4FF9-B85B-D491B13ACAE7}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{3D60F1A0-0DD9-4FF9-B85B-D491B13ACAE7}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{3D60F1A0-0DD9-4FF9-B85B-D491B13ACAE7}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4E841B34-CF2F-4751-B31D-8E1D5FCEC8F6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4E841B34-CF2F-4751-B31D-8E1D5FCEC8F6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4E841B34-CF2F-4751-B31D-8E1D5FCEC8F6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4E841B34-CF2F-4751-B31D-8E1D5FCEC8F6}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

aoc2020/Day1.cs

@@ -3,7 +3,7 @@ using System.Linq;
 
 namespace aoc2020
 {
-    internal sealed class Day1 : Day
+    public sealed class Day1 : Day
     {
         private readonly ImmutableHashSet<int> _entries;
 

aoc2020/Day2.cs

@@ -3,7 +3,7 @@ using System.Linq;
 
 namespace aoc2020
 {
-    internal sealed class Day2 : Day
+    public sealed class Day2 : Day
     {
         private readonly ImmutableList<Password> _passwords;