Support for multiple csharpier servers running at the same time, have…

… them write to a file based on the port. (#1329)

closes #1324

I wish I remembered what led me to this nreco package. Maybe because
serilog seemed overboard and I wanted something super lightweight.

Src/CSharpier.Cli.Tests/ServerTests.cs

@@ -2,6 +2,9 @@ namespace CSharpier.Cli.Tests;
 
 using System.Diagnostics;
 using System.Net.Http.Json;
+using System.Text;
+using CliWrap;
+using CliWrap.EventStream;
 using CSharpier.Cli.Server;
 using FluentAssertions;
 using NUnit.Framework;
@@ -67,4 +70,41 @@ public async Task Stuff()
             process.Kill();
         }
     }
+
+    [Test]
+    [Ignore("leaves things running when it fails and probably won't work on GH")]
+    public void RunTwo()
+    {
+        var path = Path.Combine(Directory.GetCurrentDirectory(), "dotnet-csharpier.dll");
+
+        async Task NewFunction()
+        {
+            var command = Cli.Wrap("dotnet")
+                .WithArguments(path + " --server")
+                .WithValidation(CommandResultValidation.None);
+
+            using var cts = new CancellationTokenSource();
+            cts.CancelAfter(TimeSpan.FromSeconds(5));
+
+            await foreach (var cmdEvent in command.ListenAsync(cancellationToken: cts.Token))
+            {
+                switch (cmdEvent)
+                {
+                    case StartedCommandEvent started:
+                        Console.WriteLine($"Process started; ID: {started.ProcessId}");
+                        break;
+                    case StandardOutputCommandEvent stdOut:
+                        Console.WriteLine($"Out> {stdOut.Text}");
+                        break;
+                    case StandardErrorCommandEvent stdErr:
+                        throw new Exception(stdErr.Text);
+                    case ExitedCommandEvent exited:
+                        Console.WriteLine($"Process exited; Code: {exited.ExitCode}");
+                        break;
+                }
+            }
+        }
+
+        Task.WaitAll(NewFunction(), NewFunction());
+    }
 }

Src/CSharpier.Cli/Server/ServerFormatter.cs

@@ -1,7 +1,6 @@
 namespace CSharpier.Cli.Server;
 
 using System.Net;
-using System.Net.NetworkInformation;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Hosting.Server.Features;
@@ -32,11 +31,21 @@ public static async Task<int> StartServer(
             ["Logging:File:FileSizeLimitBytes"] = "10000",
         };
         builder.Configuration.AddInMemoryCollection(values);
+        var currentPort = port ?? 0;
         builder.Services.AddLogging(loggingBuilder =>
         {
             loggingBuilder.AddFile(
-                Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "server.log"),
-                append: true
+                Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "server{0}.log"),
+                o =>
+                {
+                    // name files based on the port so that multiple processes can log without fighting over a file
+                    // however before the server is started fully we won't have a port
+                    // this empty error handler will make sure if two processes both try to use that initial file
+                    // at the same time they won't crash
+                    o.HandleFileError = _ => { };
+                    o.FormatLogFileName = name =>
+                        string.Format(name, currentPort == 0 ? string.Empty : currentPort);
+                }
             );
         });
 
@@ -50,6 +59,7 @@ var address in (app as IApplicationBuilder)
             )
             {
                 var uri = new Uri(address);
+                currentPort = uri.Port;
                 logger.LogInformation("Started on " + uri.Port);
             }
         });

Src/CSharpier/DebugLogger.cs

@@ -7,7 +7,7 @@ internal class DebugLogger
     private static object lockObject = new();
 
     [Conditional("DEBUG")]
-    public static void Log(string message)
+    public static void Log(object message)
     {
         lock (lockObject)
         {