add optional port parameter to UseReactDevelopmentServer and `UseAn…

…gularCliServer`

src/Microsoft.AspNetCore.SpaServices.Extensions/AngularCli/AngularCliMiddleware.cs

@@ -23,7 +23,8 @@ internal static class AngularCliMiddleware
 
  public static void Attach(
  ISpaBuilder spaBuilder,
- string npmScriptName)
+ string npmScriptName,
+ int? spaPort)
  {
  var sourcePath = spaBuilder.Options.SourcePath;
  if (string.IsNullOrEmpty(sourcePath))
@@ -36,10 +37,25 @@ public static void Attach(
  throw new ArgumentException("Cannot be null or empty", nameof(npmScriptName));
  }
 
- // Start Angular CLI and attach to middleware pipeline
- var appBuilder = spaBuilder.ApplicationBuilder;
- var logger = LoggerFinder.GetOrCreateLogger(appBuilder, LogCategoryName);
- var angularCliServerInfoTask = StartAngularCliServerAsync(sourcePath, npmScriptName, logger);
+ // We have to start the server by ourself if there wasn't any port specified
+ // or the specified port is still free (unused).
+ var shouldStartServer = !spaPort.HasValue || TcpPortFinder.TestPortAvailability(spaPort.Value);
+
+ Task<AngularCliServerInfo> angularCliServerInfoTask;
+ if (shouldStartServer)
+ {
+ // Start Angular CLI and attach to middleware pipeline
+ var appBuilder = spaBuilder.ApplicationBuilder;
+ var logger = LoggerFinder.GetOrCreateLogger(appBuilder, LogCategoryName);
+ angularCliServerInfoTask = StartAngularCliServerAsync(sourcePath, npmScriptName, logger);
+ }
+ else
+ {
+ angularCliServerInfoTask = Task.FromResult(new AngularCliServerInfo
+ {
+ Port = spaPort.Value
+ });
+ }
 
  // Everything we proxy is hardcoded to target http://localhost because:
  // - the requests are always from the local machine (we're not accepting remote

src/Microsoft.AspNetCore.SpaServices.Extensions/AngularCli/AngularCliMiddlewareExtensions.cs

@@ -21,9 +21,11 @@ public static class AngularCliMiddlewareExtensions
  /// </summary>
  /// <param name="spaBuilder">The <see cref="ISpaBuilder"/>.</param>
  /// <param name="npmScript">The name of the script in your package.json file that launches the Angular CLI process.</param>
+ /// <param name="spaPort">The port which the create-react-app server should listen to (optional).</param>
  public static void UseAngularCliServer(
  this ISpaBuilder spaBuilder,
- string npmScript)
+ string npmScript,
+ int? spaPort = null)
  {
  if (spaBuilder == null)
  {
@@ -37,7 +39,7 @@ public static void UseAngularCliServer(
  throw new InvalidOperationException($"To use {nameof(UseAngularCliServer)}, you must supply a non-empty value for the {nameof(SpaOptions.SourcePath)} property of {nameof(SpaOptions)} when calling {nameof(SpaApplicationBuilderExtensions.UseSpa)}.");
  }
 
- AngularCliMiddleware.Attach(spaBuilder, npmScript);
+ AngularCliMiddleware.Attach(spaBuilder, npmScript, spaPort);
  }
  }
 }

src/Microsoft.AspNetCore.SpaServices.Extensions/ReactDevelopmentServer/ReactDevelopmentServerMiddleware.cs

@@ -22,7 +22,8 @@ internal static class ReactDevelopmentServerMiddleware
 
  public static void Attach(
  ISpaBuilder spaBuilder,
- string npmScriptName)
+ string npmScriptName,
+ int? spaPort)
  {
  var sourcePath = spaBuilder.Options.SourcePath;
  if (string.IsNullOrEmpty(sourcePath))
@@ -35,10 +36,22 @@ public static void Attach(
  throw new ArgumentException("Cannot be null or empty", nameof(npmScriptName));
  }
 
- // Start create-react-app and attach to middleware pipeline
- var appBuilder = spaBuilder.ApplicationBuilder;
- var logger = LoggerFinder.GetOrCreateLogger(appBuilder, LogCategoryName);
- var portTask = StartCreateReactAppServerAsync(sourcePath, npmScriptName, logger);
+ // We have to start the server by ourself if there wasn't any port specified
+ // or the specified port is still free (unused).
+ var shouldStartServer = !spaPort.HasValue || TcpPortFinder.TestPortAvailability(spaPort.Value);
+
+ Task<int> portTask;
+ if (shouldStartServer)
+ {
+ // Start create-react-app and attach to middleware pipeline
+ var appBuilder = spaBuilder.ApplicationBuilder;
+ var logger = LoggerFinder.GetOrCreateLogger(appBuilder, LogCategoryName);
+ portTask = StartCreateReactAppServerAsync(sourcePath, npmScriptName, logger);
+ }
+ else
+ {
+ portTask = Task.FromResult(spaPort.Value);
+ }
 
  // Everything we proxy is hardcoded to target http://localhost because:
  // - the requests are always from the local machine (we're not accepting remote

src/Microsoft.AspNetCore.SpaServices.Extensions/ReactDevelopmentServer/ReactDevelopmentServerMiddlewareExtensions.cs

@@ -21,9 +21,11 @@ public static class ReactDevelopmentServerMiddlewareExtensions
  /// </summary>
  /// <param name="spaBuilder">The <see cref="ISpaBuilder"/>.</param>
  /// <param name="npmScript">The name of the script in your package.json file that launches the create-react-app server.</param>
+ /// <param name="spaPort">The port which the create-react-app server should listen to (optional).</param>
  public static void UseReactDevelopmentServer(
  this ISpaBuilder spaBuilder,
- string npmScript)
+ string npmScript,
+ int? spaPort = null)
  {
  if (spaBuilder == null)
  {
@@ -37,7 +39,7 @@ public static void UseReactDevelopmentServer(
  throw new InvalidOperationException($"To use {nameof(UseReactDevelopmentServer)}, you must supply a non-empty value for the {nameof(SpaOptions.SourcePath)} property of {nameof(SpaOptions)} when calling {nameof(SpaApplicationBuilderExtensions.UseSpa)}.");
  }
 
- ReactDevelopmentServerMiddleware.Attach(spaBuilder, npmScript);
+ ReactDevelopmentServerMiddleware.Attach(spaBuilder, npmScript, spaPort);
  }
  }
 }

src/Microsoft.AspNetCore.SpaServices.Extensions/Util/TcpPortFinder.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Net;
+using System.Net.NetworkInformation;
 using System.Net.Sockets;
 
 namespace Microsoft.AspNetCore.SpaServices.Util
@@ -21,5 +22,19 @@ public static int FindAvailablePort()
  listener.Stop();
  }
  }
+
+ public static bool TestPortAvailability(int port)
+ {
+ var ipProperties = IPGlobalProperties.GetIPGlobalProperties();
+ var ipEndPoints = ipProperties.GetActiveTcpListeners();
+ foreach (var endPoint in ipEndPoints)
+ {
+ if (endPoint.Port == port)
+ {
+ return false;
+ }
+ }
+ return true;
+ }
  }
 }