Use tool assembly path for computing default pipe name

src/Microsoft.AspNetCore.Razor.Tools/PipeName.cs

@@ -23,11 +23,18 @@ namespace Microsoft.AspNetCore.Razor.Tools
         //
         // This is similar to (and based on) the code used by Roslyn in VBCSCompiler:
         // https://github.com/dotnet/roslyn/blob/c273b6a9f19570a344c274ae89185b3a2b64d93d/src/Compilers/Shared/BuildServerConnection.cs#L528
-        public static string ComputeDefault()
+        public static string ComputeDefault(string toolDirectory = null)
         {
+            if (string.IsNullOrEmpty(toolDirectory))
+            {
+                // This can be null in cases where we don't have a way of knowing the tool assembly path like when someone manually
+                // invokes the cli tool without passing in a pipe name as argument.
+                toolDirectory = AppDomain.CurrentDomain.BaseDirectory;
+            }
+
             // Include a prefix so we can't conflict with VBCSCompiler if we somehow end up in the same directory.
             // That would be a pretty wacky bug to try and unravel.
-            var baseName = ComputeBaseName("Razor:" + AppDomain.CurrentDomain.BaseDirectory);
+            var baseName = ComputeBaseName("Razor:" + toolDirectory);
 
             // Prefix with username and elevation
             var isAdmin = false;

src/Microsoft.AspNetCore.Razor.Tools/ServerProtocol/ServerConnection.cs

@@ -83,19 +83,19 @@ namespace Microsoft.AspNetCore.Razor.Tools
         public static Task<ServerResponse> RunOnServer(
             string pipeName,
             IList<string> arguments,
-            ServerPaths buildPaths,
+            ServerPaths serverPaths,
             CancellationToken cancellationToken,
             string keepAlive = null,
             bool debug = false)
         {
             if (string.IsNullOrEmpty(pipeName))
             {
-                pipeName = PipeName.ComputeDefault();
+                pipeName = PipeName.ComputeDefault(serverPaths.ClientDirectory);
             }
 
             return RunOnServerCore(
                 arguments,
-                buildPaths,
+                serverPaths,
                 pipeName: pipeName,
                 keepAlive: keepAlive,
                 timeoutOverride: null,
@@ -106,7 +106,7 @@ namespace Microsoft.AspNetCore.Razor.Tools
 
         private static async Task<ServerResponse> RunOnServerCore(
             IList<string> arguments,
-            ServerPaths buildPaths,
+            ServerPaths serverPaths,
             string pipeName,
             string keepAlive,
             int? timeoutOverride,
@@ -119,12 +119,12 @@ namespace Microsoft.AspNetCore.Razor.Tools
                 return new RejectedServerResponse();
             }
 
-            if (buildPaths.TempDirectory == null)
+            if (serverPaths.TempDirectory == null)
             {
                 return new RejectedServerResponse();
             }
 
-            var clientDir = buildPaths.ClientDirectory;
+            var clientDir = serverPaths.ClientDirectory;
             var timeoutNewProcess = timeoutOverride ?? TimeOutMsNewProcess;
             var timeoutExistingProcess = timeoutOverride ?? TimeOutMsExistingProcess;
             var clientMutexName = MutexName.GetClientMutexName(pipeName);
@@ -175,8 +175,8 @@ namespace Microsoft.AspNetCore.Razor.Tools
                 if (client != null)
                 {
                     var request = ServerRequest.Create(
-                        buildPaths.WorkingDirectory,
-                        buildPaths.TempDirectory,
+                        serverPaths.WorkingDirectory,
+                        serverPaths.TempDirectory,
                         arguments,
                         keepAlive);