Update to allow custom regex.

Very experimental Yarn support (not recommended).
Remove submodule to depreciated https://github.com/aspnet/JavaScriptServices

Author: EEParker

.gitmodules

@@ -1,8 +1,4 @@
-[submodule "JavaScriptServices"]
-	path = JavaScriptServices
-	url = https://github.com/aspnet/JavaScriptServices
-	branch = release/2.1
-[submodule "submodules/JavaScriptServices"]
-	path = submodules/JavaScriptServices
-	url = https://github.com/aspnet/JavaScriptServices
-	branch = release/2.1
+[submodule "JavaScriptServices"]
+	path = JavaScriptServices
+	url = https://github.com/aspnet/JavaScriptServices
+	branch = release/2.1

src/Util/Internals.cs

@@ -0,0 +1,221 @@
+// Copyright (c) .NET Foundation Contributors. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+// Original Source: https://github.com/aspnet/JavaScriptServices
+
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Console;
+using System;
+using System.Threading.Tasks;
+using System.Net;
+using System.Net.Sockets;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
+
+namespace VueCliMiddleware
+{
+    internal static class LoggerFinder
+    {
+        public static ILogger GetOrCreateLogger(
+            IApplicationBuilder appBuilder,
+            string logCategoryName)
+        {
+            // If the DI system gives us a logger, use it. Otherwise, set up a default one.
+            var loggerFactory = appBuilder.ApplicationServices.GetService<ILoggerFactory>();
+            var logger = loggerFactory != null
+                ? loggerFactory.CreateLogger(logCategoryName)
+                : new ConsoleLogger(logCategoryName, null, false);
+            return logger;
+        }
+    }
+
+    internal static class TaskTimeoutExtensions
+    {
+        public static async Task WithTimeout(this Task task, TimeSpan timeoutDelay, string message)
+        {
+            if (task == await Task.WhenAny(task, Task.Delay(timeoutDelay)))
+            {
+                task.Wait(); // Allow any errors to propagate
+            }
+            else
+            {
+                throw new TimeoutException(message);
+            }
+        }
+
+        public static async Task<T> WithTimeout<T>(this Task<T> task, TimeSpan timeoutDelay, string message)
+        {
+            if (task == await Task.WhenAny(task, Task.Delay(timeoutDelay)))
+            {
+                return task.Result;
+            }
+            else
+            {
+                throw new TimeoutException(message);
+            }
+        }
+    }
+
+    internal static class TcpPortFinder
+    {
+        public static int FindAvailablePort()
+        {
+            var listener = new TcpListener(IPAddress.Loopback, 0);
+            listener.Start();
+            try
+            {
+                return ((IPEndPoint)listener.LocalEndpoint).Port;
+            }
+            finally
+            {
+                listener.Stop();
+            }
+        }
+    }
+
+      /// <summary>
+    /// Wraps a <see cref="StreamReader"/> to expose an evented API, issuing notifications
+    /// when the stream emits partial lines, completed lines, or finally closes.
+    /// </summary>
+    internal class EventedStreamReader
+    {
+        public delegate void OnReceivedChunkHandler(ArraySegment<char> chunk);
+        public delegate void OnReceivedLineHandler(string line);
+        public delegate void OnStreamClosedHandler();
+
+        public event OnReceivedChunkHandler OnReceivedChunk;
+        public event OnReceivedLineHandler OnReceivedLine;
+        public event OnStreamClosedHandler OnStreamClosed;
+
+        private readonly StreamReader _streamReader;
+        private readonly StringBuilder _linesBuffer;
+
+        public EventedStreamReader(StreamReader streamReader)
+        {
+            _streamReader = streamReader ?? throw new ArgumentNullException(nameof(streamReader));
+            _linesBuffer = new StringBuilder();
+            Task.Factory.StartNew(Run);
+        }
+
+        public Task<Match> WaitForMatch(Regex regex)
+        {
+            var tcs = new TaskCompletionSource<Match>();
+            var completionLock = new object();
+
+            OnReceivedLineHandler onReceivedLineHandler = null;
+            OnStreamClosedHandler onStreamClosedHandler = null;
+
+            void ResolveIfStillPending(Action applyResolution)
+            {
+                lock (completionLock)
+                {
+                    if (!tcs.Task.IsCompleted)
+                    {
+                        OnReceivedLine -= onReceivedLineHandler;
+                        OnStreamClosed -= onStreamClosedHandler;
+                        applyResolution();
+                    }
+                }
+            }
+
+            onReceivedLineHandler = line =>
+            {
+                var match = regex.Match(line);
+                if (match.Success)
+                {
+                    ResolveIfStillPending(() => tcs.SetResult(match));
+                }
+            };
+
+            onStreamClosedHandler = () =>
+            {
+                ResolveIfStillPending(() => tcs.SetException(new EndOfStreamException()));
+            };
+
+            OnReceivedLine += onReceivedLineHandler;
+            OnStreamClosed += onStreamClosedHandler;
+
+            return tcs.Task;
+        }
+
+        private async Task Run()
+        {
+            var buf = new char[8 * 1024];
+            while (true)
+            {
+                var chunkLength = await _streamReader.ReadAsync(buf, 0, buf.Length);
+                if (chunkLength == 0)
+                {
+                    OnClosed();
+                    break;
+                }
+
+                OnChunk(new ArraySegment<char>(buf, 0, chunkLength));
+
+                var lineBreakPos = Array.IndexOf(buf, '\n', 0, chunkLength);
+                if (lineBreakPos < 0)
+                {
+                    _linesBuffer.Append(buf, 0, chunkLength);
+                }
+                else
+                {
+                    _linesBuffer.Append(buf, 0, lineBreakPos + 1);
+                    OnCompleteLine(_linesBuffer.ToString());
+                    _linesBuffer.Clear();
+                    _linesBuffer.Append(buf, lineBreakPos + 1, chunkLength - (lineBreakPos + 1));
+                }
+            }
+        }
+
+        private void OnChunk(ArraySegment<char> chunk)
+        {
+            var dlg = OnReceivedChunk;
+            dlg?.Invoke(chunk);
+        }
+
+        private void OnCompleteLine(string line)
+        {
+            var dlg = OnReceivedLine;
+            dlg?.Invoke(line);
+        }
+
+        private void OnClosed()
+        {
+            var dlg = OnStreamClosed;
+            dlg?.Invoke();
+        }
+    }
+
+    /// <summary>
+    /// Captures the completed-line notifications from a <see cref="EventedStreamReader"/>,
+    /// combining the data into a single <see cref="string"/>.
+    /// </summary>
+    internal class EventedStreamStringReader : IDisposable
+    {
+        private EventedStreamReader _eventedStreamReader;
+        private bool _isDisposed;
+        private StringBuilder _stringBuilder = new StringBuilder();
+
+        public EventedStreamStringReader(EventedStreamReader eventedStreamReader)
+        {
+            _eventedStreamReader = eventedStreamReader
+                ?? throw new ArgumentNullException(nameof(eventedStreamReader));
+            _eventedStreamReader.OnReceivedLine += OnReceivedLine;
+        }
+
+        public string ReadAsString() => _stringBuilder.ToString();
+
+        private void OnReceivedLine(string line) => _stringBuilder.AppendLine(line);
+
+        public void Dispose()
+        {
+            if (!_isDisposed)
+            {
+                _eventedStreamReader.OnReceivedLine -= OnReceivedLine;
+                _isDisposed = true;
+            }
+        }
+    }
+}

src/Util/ScriptRunner.cs

@@ -0,0 +1,138 @@
+// Copyright (c) .NET Foundation Contributors. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+// Original Source: https://github.com/aspnet/JavaScriptServices
+
+using Microsoft.Extensions.Logging;
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using System.Text.RegularExpressions;
+using System.Collections.Generic;
+
+namespace VueCliMiddleware
+{
+    /// <summary>
+    /// Executes the <c>script</c> entries defined in a <c>package.json</c> file,
+    /// capturing any output written to stdio.
+    /// </summary>
+    internal class ScriptRunner
+    {
+        public EventedStreamReader StdOut { get; }
+        public EventedStreamReader StdErr { get; }
+
+        public ScriptRunnerType Runner { get; }
+
+        private string GetExeName() => Runner == ScriptRunnerType.Npm ? "npm" : "yarn";
+        private string GetArgPrefix() => Runner == ScriptRunnerType.Npm ? "run " : "";
+        private string GetArgSuffix() => Runner == ScriptRunnerType.Npm ? "-- " : "";
+
+        private static Regex AnsiColorRegex = new Regex("\x001b\\[[0-9;]*m", RegexOptions.None, TimeSpan.FromSeconds(1));
+
+        public ScriptRunner(string workingDirectory, string scriptName, string arguments, IDictionary<string, string> envVars, ScriptRunnerType runner)
+        {
+            if (string.IsNullOrEmpty(workingDirectory))
+            {
+                throw new ArgumentException("Cannot be null or empty.", nameof(workingDirectory));
+            }
+
+            if (string.IsNullOrEmpty(scriptName))
+            {
+                throw new ArgumentException("Cannot be null or empty.", nameof(scriptName));
+            }
+
+            Runner = runner;
+
+            var npmExe = GetExeName();
+            var completeArguments = $"{GetArgPrefix()}{scriptName} {GetArgSuffix()}{arguments ?? string.Empty}";
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+                // On Windows, the NPM executable is a .cmd file, so it can't be executed
+                // directly (except with UseShellExecute=true, but that's no good, because
+                // it prevents capturing stdio). So we need to invoke it via "cmd /c".
+                npmExe = "cmd";
+                completeArguments = $"/c npm {completeArguments}";
+            }
+
+            var processStartInfo = new ProcessStartInfo(npmExe)
+            {
+                Arguments = completeArguments,
+                UseShellExecute = false,
+                RedirectStandardInput = true,
+                RedirectStandardOutput = true,
+                RedirectStandardError = true,
+                WorkingDirectory = workingDirectory
+            };
+
+            if (envVars != null)
+            {
+                foreach (var keyValuePair in envVars)
+                {
+                    processStartInfo.Environment[keyValuePair.Key] = keyValuePair.Value;
+                }
+            }
+
+            var process = LaunchNodeProcess(processStartInfo);
+            StdOut = new EventedStreamReader(process.StandardOutput);
+            StdErr = new EventedStreamReader(process.StandardError);
+        }
+
+        public void AttachToLogger(ILogger logger)
+        {
+            // When the NPM task emits complete lines, pass them through to the real logger
+            StdOut.OnReceivedLine += line =>
+            {
+                if (!string.IsNullOrWhiteSpace(line))
+                {
+                    // NPM tasks commonly emit ANSI colors, but it wouldn't make sense to forward
+                    // those to loggers (because a logger isn't necessarily any kind of terminal)
+                    logger.LogInformation(StripAnsiColors(line) + "\r\n");
+                }
+            };
+
+            StdErr.OnReceivedLine += line =>
+            {
+                if (!string.IsNullOrWhiteSpace(line))
+                {
+                    logger.LogError(StripAnsiColors(line + "\r\n"));
+                }
+            };
+
+            // But when it emits incomplete lines, assume this is progress information and
+            // hence just pass it through to StdOut regardless of logger config.
+            StdErr.OnReceivedChunk += chunk =>
+            {
+                var containsNewline = Array.IndexOf(chunk.Array, '\n', chunk.Offset, chunk.Count) >= 0;
+
+                if (!containsNewline)
+                {
+                    Console.Write(chunk.Array, chunk.Offset, chunk.Count);
+                }
+            };
+        }
+
+        private static string StripAnsiColors(string line)
+            => AnsiColorRegex.Replace(line, string.Empty);
+
+        private static Process LaunchNodeProcess(ProcessStartInfo startInfo)
+        {
+            try
+            {
+                var process = Process.Start(startInfo);
+
+                // See equivalent comment in OutOfProcessNodeInstance.cs for why
+                process.EnableRaisingEvents = true;
+
+                return process;
+            }
+            catch (Exception ex)
+            {
+                var message = $"Failed to start '{startInfo.FileName}'. To resolve this:.\n\n"
+                            + $"[1] Ensure that '{startInfo.FileName}' is installed and can be found in one of the PATH directories.\n"
+                            + $"    Current PATH enviroment variable is: { Environment.GetEnvironmentVariable("PATH") }\n"
+                            + "    Make sure the executable is in one of those directories, or update your PATH.\n\n"
+                            + "[2] See the InnerException for further details of the cause.";
+                throw new InvalidOperationException(message, ex);
+            }
+        }
+    }
+}

src/Util/ScriptRunnerType.cs

@@ -0,0 +1,8 @@
+namespace VueCliMiddleware
+{
+    public enum ScriptRunnerType
+    {
+        Npm,
+        Yarn
+    }
+}