From b5ab098fb6ae7060527eb60e61412ca09aa04896 Mon Sep 17 00:00:00 2001
From: Mike Surcouf <mike@surcouf.je>
Date: Sat, 30 Dec 2023 23:42:47 +0000
Subject: [PATCH] Reduce contention on destination file

---
 CompileJS.cs                | 35 ++++++++++++++++++++++++++---------
 MudBlazor.JSCompiler.csproj |  2 +-
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/CompileJS.cs b/CompileJS.cs
index 2eb5e0c..af4b26f 100644
--- a/CompileJS.cs
+++ b/CompileJS.cs
@@ -1,4 +1,6 @@
+using System;
 using System.IO;
+using System.Text;
 using Microsoft.Build.Framework;
 using Microsoft.Build.Utilities;
 
@@ -15,21 +17,36 @@ public class CompileJS : Task
 
         public override bool Execute()
         {
-            File.Delete(DestinationFile);
             var sourceDirectory = new DirectoryInfo(SourceDirectory);
-            var files = sourceDirectory.GetFiles("*.js");
+            var sourceFiles = sourceDirectory.GetFiles("*.js");
+            var maxSourceWriteTime = new DateTime();
+            var combinedJS = new StringBuilder();
 
-            foreach (var file in files)
+            foreach (var sourceFile in sourceFiles)
             {
-                var fileText = File.ReadAllText(file.FullName);
-                File.AppendAllText(DestinationFile, fileText);
+                maxSourceWriteTime = sourceFile.LastWriteTime > maxSourceWriteTime ? sourceFile.LastWriteTime : maxSourceWriteTime;
+                var fileText = File.ReadAllText(sourceFile.FullName);
+                combinedJS.Append(fileText);
             }
 
-            using (var reader = new StreamReader(DestinationFile))
+            var compressedJS = JavaScriptCompressor.Compress(combinedJS.ToString());
+
+            if (File.Exists(DestinationFile))
+            {
+                if (File.GetLastWriteTime(DestinationFile) < maxSourceWriteTime)
+                {
+                    File.WriteAllText(DestinationFile, compressedJS);
+                    Log.LogMessage(MessageImportance.High, $"{DestinationFile} Updated");
+                }
+                else
+                {
+                    Log.LogMessage(MessageImportance.High, $"{DestinationFile} UpToDate");
+                }
+            }
+            else
             {
-                var writer = new StringWriter();
-                JavaScriptCompressor.Compress(reader, writer);
-                File.WriteAllText(DestinationFile, writer.GetStringBuilder().ToString(), reader.CurrentEncoding);
+                File.WriteAllText(DestinationFile, compressedJS);
+                Log.LogMessage(MessageImportance.High, $"{DestinationFile} Created");
             }
 
             GeneratedFile = new TaskItem(DestinationFile);
diff --git a/MudBlazor.JSCompiler.csproj b/MudBlazor.JSCompiler.csproj
index 9ab34da..4585c16 100644
--- a/MudBlazor.JSCompiler.csproj
+++ b/MudBlazor.JSCompiler.csproj
@@ -3,7 +3,7 @@
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
     <PackageId>MudBlazor.JSCompiler</PackageId>
-    <Version>1.0.7</Version>
+    <Version>1.0.8</Version>
     <Authors>mikes-gh</Authors>
     <Description>MudBlazor JS Compiler Library</Description>
     <PackageDescription>MudBlazor JS Compiler Library</PackageDescription>