enable nullable for solution

Author: arturcic

src/Directory.Build.props

@@ -16,10 +16,12 @@
         <RepositoryUrl>https://github.com/GitTools/GitVersion</RepositoryUrl>
         <RepositoryType>git</RepositoryType>
 
-        <NoWarn>1591</NoWarn>
+        <NoWarn>1591,8618</NoWarn>
         <DebugType>embedded</DebugType>
         <LangVersion>10</LangVersion>
         <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+
     </PropertyGroup>
     <PropertyGroup>
         <PackageVersion_LibGit2Sharp>0.27.0-preview-0175</PackageVersion_LibGit2Sharp>

src/GitTools.Testing/Fixtures/RepositoryFixtureBase.cs

@@ -8,7 +8,6 @@ namespace GitTools.Testing;
 /// </summary>
 public abstract class RepositoryFixtureBase : IDisposable
 {
-    private readonly SequenceDiagram sequenceDiagram;
 
     protected RepositoryFixtureBase(Func<string, IRepository> repoBuilder)
         : this(repoBuilder(PathHelper.GetTempPath()))
@@ -17,7 +16,7 @@ protected RepositoryFixtureBase(Func<string, IRepository> repoBuilder)
 
     protected RepositoryFixtureBase(IRepository repository)
     {
-        this.sequenceDiagram = new SequenceDiagram();
+        this.SequenceDiagram = new SequenceDiagram();
         Repository = repository;
         Repository.Config.Set("user.name", "Test");
         Repository.Config.Set("user.email", "[email protected]");
@@ -27,7 +26,8 @@ protected RepositoryFixtureBase(IRepository repository)
 
     public string RepositoryPath => Repository.Info.WorkingDirectory.TrimEnd('\\');
 
-    public SequenceDiagram SequenceDiagram => this.sequenceDiagram;
+    public SequenceDiagram SequenceDiagram { get; }
+
 
     /// <summary>
     ///     Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
@@ -57,10 +57,10 @@ protected virtual void Dispose(bool disposing)
                 e.Message);
         }
 
-        this.sequenceDiagram.End();
+        this.SequenceDiagram.End();
         Console.WriteLine("**Visualisation of test:**");
         Console.WriteLine(string.Empty);
-        Console.WriteLine(this.sequenceDiagram.GetDiagram());
+        Console.WriteLine(this.SequenceDiagram.GetDiagram());
     }
 
     public void Checkout(string branch) => Commands.Checkout(Repository, branch);
@@ -75,28 +75,28 @@ public void MakeATaggedCommit(string tag)
 
     public void ApplyTag(string tag)
     {
-        this.sequenceDiagram.ApplyTag(tag, Repository.Head.FriendlyName);
+        this.SequenceDiagram.ApplyTag(tag, Repository.Head.FriendlyName);
         Repository.ApplyTag(tag);
     }
 
-    public void BranchTo(string branchName, string @as = null)
+    public void BranchTo(string branchName, string? @as = null)
     {
-        this.sequenceDiagram.BranchTo(branchName, Repository.Head.FriendlyName, @as);
+        this.SequenceDiagram.BranchTo(branchName, Repository.Head.FriendlyName, @as);
         var branch = Repository.CreateBranch(branchName);
         Commands.Checkout(Repository, branch);
     }
 
-    public void BranchToFromTag(string branchName, string fromTag, string onBranch, string @as = null)
+    public void BranchToFromTag(string branchName, string fromTag, string onBranch, string? @as = null)
     {
-        this.sequenceDiagram.BranchToFromTag(branchName, fromTag, onBranch, @as);
+        this.SequenceDiagram.BranchToFromTag(branchName, fromTag, onBranch, @as);
         var branch = Repository.CreateBranch(branchName);
         Commands.Checkout(Repository, branch);
     }
 
     public void MakeACommit()
     {
         var to = Repository.Head.FriendlyName;
-        this.sequenceDiagram.MakeACommit(to);
+        this.SequenceDiagram.MakeACommit(to);
         Repository.MakeACommit();
     }
 
@@ -105,7 +105,7 @@ public void MakeACommit()
     /// </summary>
     public void MergeNoFF(string mergeSource)
     {
-        this.sequenceDiagram.Merge(mergeSource, Repository.Head.FriendlyName);
+        this.SequenceDiagram.Merge(mergeSource, Repository.Head.FriendlyName);
         Repository.MergeNoFF(mergeSource, Generate.SignatureNow());
     }
 

src/GitTools.Testing/Fixtures/SequenceDiagram.cs

@@ -32,7 +32,7 @@ public SequenceDiagram()
     /// <summary>
     /// Creates a participant in the sequence diagram
     /// </summary>
-    public void Participant(string participant, string @as = null)
+    public void Participant(string participant, string? @as = null)
     {
         this.participants.Add(participant, @as ?? participant);
         if (@as == null)
@@ -49,7 +49,7 @@ public void Participant(string participant, string @as = null)
     /// <summary>
     /// Appends a note over one or many participants to the sequence diagram
     /// </summary>
-    public void NoteOver(string noteText, string startParticipant, string endParticipant = null, string prefix = null, string color = null) =>
+    public void NoteOver(string noteText, string startParticipant, string? endParticipant = null, string? prefix = null, string? color = null) =>
         this.diagramBuilder.AppendLineFormat(
             prefix + @"note over {0}{1}{2}
   {3}
@@ -67,7 +67,7 @@ public void NoteOver(string noteText, string startParticipant, string endPartici
     /// <summary>
     /// Appends branching from a branch to another branch, @as can override the participant name
     /// </summary>
-    public void BranchTo(string branchName, string currentName, string @as)
+    public void BranchTo(string branchName, string currentName, string? @as)
     {
         if (!this.participants.ContainsKey(branchName))
         {
@@ -84,7 +84,7 @@ public void BranchTo(string branchName, string currentName, string @as)
     /// <summary>
     /// Appends branching from a tag to a specified branch to the sequence diagram
     /// </summary>
-    public void BranchToFromTag(string branchName, string fromTag, string onBranch, string @as)
+    public void BranchToFromTag(string branchName, string fromTag, string onBranch, string? @as)
     {
         if (!this.participants.ContainsKey(branchName))
         {

src/GitTools.Testing/Generate.cs

@@ -19,5 +19,5 @@ public static Signature SignatureNow()
     /// <summary>
     /// Creates a libgit2sharp signature at the specified time
     /// </summary>
-    public static Signature Signature(DateTimeOffset dateTimeOffset) => new("A. U. Thor", "[email protected]", dateTimeOffset);
+    private static Signature Signature(DateTimeOffset dateTimeOffset) => new("A. U. Thor", "[email protected]", dateTimeOffset);
 }

src/GitTools.Testing/GitTestExtensions.cs

@@ -7,7 +7,7 @@ public static class GitTestExtensions
 {
     private static int _pad = 1;
 
-    public static Commit MakeACommit(this IRepository repository, string commitMessage = null) => CreateFileAndCommit(repository, Guid.NewGuid().ToString(), commitMessage);
+    public static Commit MakeACommit(this IRepository repository, string? commitMessage = null) => CreateFileAndCommit(repository, Guid.NewGuid().ToString(), commitMessage);
 
     public static void MergeNoFF(this IRepository repository, string branch) => MergeNoFF(repository, branch, Generate.SignatureNow());
 
@@ -20,7 +20,7 @@ public static Commit[] MakeCommits(this IRepository repository, int numCommitsTo
         .Select(_ => repository.MakeACommit())
         .ToArray();
 
-    private static Commit CreateFileAndCommit(this IRepository repository, string relativeFileName, string commitMessage = null)
+    private static Commit CreateFileAndCommit(this IRepository repository, string relativeFileName, string? commitMessage = null)
     {
         var randomFile = Path.Combine(repository.Info.WorkingDirectory, relativeFileName);
         if (File.Exists(randomFile))
@@ -68,7 +68,7 @@ public static Commit CreatePullRequestRef(this IRepository repository, string fr
         return commit;
     }
 
-    public static void ExecuteGitCmd(string gitCmd, Action<string> writer = null)
+    public static void ExecuteGitCmd(string gitCmd, Action<string>? writer = null)
     {
         var output = new StringBuilder();
         try

src/GitTools.Testing/Internal/ObjectExtensions.cs

@@ -0,0 +1,13 @@
+namespace GitTools.Testing.Internal;
+
+public static class ObjectExtensions
+{
+    public static void Deconstruct<TKey, TValue>(
+        this KeyValuePair<TKey, TValue> kvp,
+        out TKey key,
+        out TValue value)
+    {
+        key = kvp.Key;
+        value = kvp.Value;
+    }
+}

src/GitTools.Testing/Internal/ProcessHelper.cs

@@ -8,9 +8,9 @@ public static class ProcessHelper
     private static readonly object LockObject = new();
 
     // http://social.msdn.microsoft.com/Forums/en/netfxbcl/thread/f6069441-4ab1-4299-ad6a-b8bb9ed36be3
-    private static Process Start(ProcessStartInfo startInfo)
+    private static Process? Start(ProcessStartInfo startInfo)
     {
-        Process process;
+        Process? process;
 
         lock (LockObject)
         {
@@ -74,15 +74,13 @@ private static Process Start(ProcessStartInfo startInfo)
     }
 
     // http://csharptest.net/532/using-processstart-to-capture-console-output/
-    public static int Run(Action<string> output, Action<string> errorOutput, TextReader input, string exe, string args, string workingDirectory, params KeyValuePair<string, string>[] environmentalVariables)
+    public static int Run(Action<string> output, Action<string> errorOutput, TextReader? input, string exe, string args, string workingDirectory, params KeyValuePair<string, string>[] environmentalVariables)
     {
         if (string.IsNullOrEmpty(exe))
             throw new ArgumentNullException(nameof(exe));
         if (output == null)
             throw new ArgumentNullException(nameof(output));
 
-        workingDirectory ??= Environment.CurrentDirectory;
-
         var psi = new ProcessStartInfo
         {
             UseShellExecute = false,
@@ -96,23 +94,31 @@ public static int Run(Action<string> output, Action<string> errorOutput, TextRea
             FileName = exe,
             Arguments = args
         };
-        foreach (var environmentalVariable in environmentalVariables)
+        foreach (var (key, value) in environmentalVariables)
         {
-            if (psi.EnvironmentVariables.ContainsKey(environmentalVariable.Key))
+            var psiEnvironmentVariables = psi.EnvironmentVariables;
+            if (psiEnvironmentVariables.ContainsKey(key) && string.IsNullOrEmpty(value))
             {
-                psi.EnvironmentVariables[environmentalVariable.Key] = environmentalVariable.Value;
+                psiEnvironmentVariables.Remove(key);
             }
-            else
+            else if (psiEnvironmentVariables.ContainsKey(key))
             {
-                psi.EnvironmentVariables.Add(environmentalVariable.Key, environmentalVariable.Value);
+                psiEnvironmentVariables[key] = value;
             }
-            if (psi.EnvironmentVariables.ContainsKey(environmentalVariable.Key) && environmentalVariable.Value == null)
+            else
             {
-                psi.EnvironmentVariables.Remove(environmentalVariable.Key);
+                psiEnvironmentVariables.Add(key, value);
             }
         }
 
         using var process = Start(psi);
+
+        if (process is null)
+        {
+            // FIX ME: What error code do you want to return?
+            return -1;
+        }
+
         using var mreOut = new ManualResetEvent(false);
         using var mreErr = new ManualResetEvent(false);
         process.EnableRaisingEvents = true;
@@ -135,8 +141,8 @@ public static int Run(Action<string> output, Action<string> errorOutput, TextRea
         };
         process.BeginErrorReadLine();
 
-        string line;
-        while (input != null && null != (line = input.ReadLine()))
+        string? line;
+        while ((line = input?.ReadLine()) != null)
             process.StandardInput.WriteLine(line);
 
         process.StandardInput.Close();
@@ -160,7 +166,7 @@ private enum NativeErrorCode
     }
 
     [Flags]
-    public enum ErrorModes
+    private enum ErrorModes
     {
         Default = 0x0,
         FailCriticalErrors = 0x1,
@@ -169,7 +175,7 @@ public enum ErrorModes
         NoOpenFileErrorBox = 0x8000
     }
 
-    private struct ChangeErrorMode : IDisposable
+    private readonly struct ChangeErrorMode : IDisposable
     {
         private readonly int oldMode;
 

src/GitTools.Testing/Internal/StringBuilderExtensions.cs

@@ -5,7 +5,7 @@ namespace GitTools.Testing.Internal;
 internal static class StringBuilderExtensions
 {
     [StringFormatMethod("format")]
-    public static void AppendLineFormat(this StringBuilder stringBuilder, string format, params object[] args)
+    public static void AppendLineFormat(this StringBuilder stringBuilder, string format, params object?[] args)
     {
         stringBuilder.AppendFormat(format, args);
         stringBuilder.AppendLine();