Fixed infinite loop cycles when running dotnet watch.

src/StrawberryShake/SourceGenerator/src/CodeGeneration.CSharp.Analyzers/CSharpClientGenerator.cs

@@ -20,6 +20,7 @@ namespace StrawberryShake.CodeGeneration.CSharp.Analyzers
     public class CSharpClientGenerator : ISourceGenerator
     {
         private const string _category = "StrawberryShakeGenerator";
+        private readonly MD5DocumentHashProvider _hashProvider = new();
 
         private static string _location = System.IO.Path.GetDirectoryName(
             typeof(CSharpClientGenerator).Assembly.Location)!;
@@ -94,8 +95,6 @@ private void Execute(ClientGeneratorContext context)
         {
             try
             {
-                CreateDirectoryIfNotExists(context.OutputDirectory);
-
                 if (!TryGenerateClient(context, out CSharpGeneratorResult? result))
                 {
                     // there were unexpected errors and we will stop generating this client.
@@ -157,14 +156,13 @@ private void WriteGraphQLQuery(
             string documentName = document.Hash + ".graphql";
             string fileName = IOPath.Combine(persistedQueryDirectory, documentName);
 
-            context.Log.WriteDocument(documentName);
-
-            if (File.Exists(fileName))
+            // we only write the file if it does not exist to not trigger
+            // dotnet watch.
+            if (!File.Exists(fileName))
             {
-                File.Delete(fileName);
+                context.Log.WriteDocument(documentName);
+                File.WriteAllText(fileName, document.SourceText, Encoding.UTF8);
             }
-
-            File.WriteAllText(fileName, document.SourceText, Encoding.UTF8);
         }
 
         private void Clean(ClientGeneratorContext context)
@@ -362,14 +360,6 @@ private IReadOnlyList<string> GetGraphQLConfigFiles(
                 .Where(t => IOPath.GetFileName(t).EqualsOrdinal(".graphqlrc.json"))
                 .ToList();
 
-        private void CreateDirectoryIfNotExists(string? directory)
-        {
-            if (!Directory.Exists(directory))
-            {
-                Directory.CreateDirectory(directory);
-            }
-        }
-
         private ILogger CreateLogger(GeneratorExecutionContext context)
         {
             if (context.AnalyzerConfigOptions.GlobalOptions.TryGetValue(

src/StrawberryShake/SourceGenerator/src/CodeGeneration.CSharp.Analyzers/ClientGeneratorContext.cs

@@ -8,6 +8,7 @@
 using static StrawberryShake.CodeGeneration.ErrorHelper;
 using static StrawberryShake.CodeGeneration.CSharp.Analyzers.SourceGeneratorErrorCodes;
 using static StrawberryShake.CodeGeneration.CSharp.Analyzers.DiagnosticErrorHelper;
+using System.IO;
 
 namespace StrawberryShake.CodeGeneration.CSharp.Analyzers
 {
@@ -28,7 +29,7 @@ public ClientGeneratorContext(
             Filter = filter;
             ClientDirectory = clientDirectory;
             OutputDirectory = IOPath.Combine(
-                clientDirectory, 
+                clientDirectory,
                 settings.OutputDirectoryName ?? ".generated");
             OutputFiles = settings.OutputDirectoryName is not null;
             _allDocuments = allDocuments;
@@ -127,5 +128,24 @@ public string GetNamespace()
 
             return null;
         }
+
+        public string? GetStateDirectory()
+        {
+            if (Execution.AnalyzerConfigOptions.GlobalOptions.TryGetValue(
+                "build_property.StrawberryShake_State",
+                out string? value) &&
+                !string.IsNullOrEmpty(value))
+            {
+                if (!Directory.Exists(value))
+                {
+                    Directory.CreateDirectory(value);
+                }
+
+                return value;
+            }
+
+            throw new GraphQLException(
+                $"The MSBuild property `StrawberryShake_State` cannot be empty.");
+        }
     }
 }

src/StrawberryShake/SourceGenerator/src/CodeGeneration.CSharp.Analyzers/SingleFileDocumentWriter.cs

@@ -3,15 +3,18 @@
 using System.Text;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Text;
+using HotChocolate.Language;
 using IOPath = System.IO.Path;
 
 namespace StrawberryShake.CodeGeneration.CSharp.Analyzers
 {
     public class SingleFileDocumentWriter : IDocumentWriter
     {
-        private StringBuilder _content = new();
+        private readonly StringBuilder _content = new();
+        private readonly MD5DocumentHashProvider _hashProvider = new();
         private GeneratorExecutionContext? _execution;
         private string? _fileName;
+        private string? _hashFile;
         private bool _emitCode;
 
         public void WriteDocument(ClientGeneratorContext context, SourceDocument document)
@@ -28,6 +31,9 @@ public void WriteDocument(ClientGeneratorContext context, SourceDocument documen
                 _fileName = IOPath.Combine(
                     context.OutputDirectory,
                     $"{context.Settings.Name}.StrawberryShake.cs");
+                _hashFile = IOPath.Combine(
+                    context.GetStateDirectory(),
+                    context.Settings.Name + ".md5");
                 _emitCode = context.Settings.EmitGeneratedCode;
                 context.FileNames.Add(_fileName);
             }
@@ -51,19 +57,34 @@ public void Flush()
 
             if (_emitCode && _fileName is not null)
             {
-                string directory = IOPath.GetDirectoryName(_fileName);
+                string? hash = _hashFile is not null && File.Exists(_hashFile)
+                    ? File.ReadAllText(_hashFile)
+                    : null;
 
-                if (!Directory.Exists(directory))
-                {
-                    Directory.CreateDirectory(directory);
-                }
+                string currentHash = _hashProvider.ComputeHash(
+                    Encoding.UTF8.GetBytes(_content.ToString()));
 
-                if (File.Exists(_fileName))
+                bool fileExists = File.Exists(_fileName);
+
+                // we only write the file if it has changed so we do not trigger a loop on
+                // dotnet watch.
+                if (!fileExists || !currentHash.Equals(hash, StringComparison.Ordinal))
                 {
-                    File.Delete(_fileName);
-                }
+                    string directory = IOPath.GetDirectoryName(_fileName);
 
-                File.WriteAllText(_fileName, _content.ToString(), Encoding.UTF8);
+                    if (!Directory.Exists(directory))
+                    {
+                        Directory.CreateDirectory(directory);
+                    }
+
+                    if (fileExists)
+                    {
+                        File.Delete(_fileName);
+                    }
+
+                    File.WriteAllText(_fileName, _content.ToString(), Encoding.UTF8);
+                    File.WriteAllText(_hashFile, currentHash, Encoding.UTF8);
+                }
             }
         }
     }

src/StrawberryShake/SourceGenerator/src/CodeGeneration.CSharp.Analyzers/StrawberryShake.CodeGeneration.CSharp.Analyzers.csproj

@@ -21,7 +21,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="StrawberryShake.CodeGeneration.CSharp" Version="11.2.0-local.100" PrivateAssets="all" GeneratePathProperty="true" />
+    <PackageReference Include="StrawberryShake.CodeGeneration.CSharp" Version="11.2.0-local-152" PrivateAssets="all" GeneratePathProperty="true" />
     <PackageReference Include="DotNet.Glob" Version="3.1.2" PrivateAssets="all" GeneratePathProperty="true" />
   </ItemGroup>
 

src/StrawberryShake/SourceGenerator/src/MSBuild/StrawberryShake.props

@@ -46,6 +46,7 @@
     <CompilerVisibleProperty Include="StrawberryShake_LogFile" />
     <CompilerVisibleProperty Include="StrawberryShake_BuildDirectory" />
     <CompilerVisibleProperty Include="StrawberryShake_PersistedQueryDirectory" />
+    <CompilerVisibleProperty Include="StrawberryShake_State" />
   </ItemGroup>
 
 </Project>

src/StrawberryShake/SourceGenerator/src/MSBuild/StrawberryShake.targets

@@ -8,6 +8,7 @@
     <StrawberryShake_DesignTimeBuild Condition="$(IsOmniSharp)">false</StrawberryShake_DesignTimeBuild>
     <StrawberryShake_DefaultNamespace Condition="'$(StrawberryShake_DefaultNamespace)' == ''">$(RootNamespace)</StrawberryShake_DefaultNamespace>
     <StrawberryShake_DefaultNamespace Condition="'$(StrawberryShake_DefaultNamespace)' == ''">$(AssemblyName)</StrawberryShake_DefaultNamespace>
+    <StrawberryShake_State>$(BaseIntermediateOutputPath)\berry</StrawberryShake_State>
   </PropertyGroup>
 
   <Import Project="$(MSBuildThisFileDirectory)VSCode.targets" Condition="'$(IsOmniSharp)' == 'true'" />