implement server handshake test

.travis.yml

@@ -26,7 +26,7 @@ env:
     - SBT_CMD="scripted dependency-management/*4of4"
     - SBT_CMD="scripted java/* package/* reporter/* run/* project-load/*"
     - SBT_CMD="scripted project/*1of2"
-    - SBT_CMD="scripted project/*2of2"
+    - SBT_CMD="scripted project/*2of2 server/*"
     - SBT_CMD="scripted source-dependencies/*1of3"
     - SBT_CMD="scripted source-dependencies/*2of3"
     - SBT_CMD="scripted source-dependencies/*3of3"

sbt/src/sbt-test/server/handshake/Client.scala

@@ -0,0 +1,35 @@
+package example
+
+import java.net.{ URI, Socket, InetAddress, SocketException }
+import sbt.io._
+import sbt.io.syntax._
+import java.io.File
+
+object Client extends App {
+  val host = "127.0.0.1"
+  val port = 5123
+  val delimiter: Byte = '\n'.toByte
+
+  println("hello")
+  Thread.sleep(1000)
+
+  val connection = getConnection
+  val out = connection.getOutputStream
+  val in = connection.getInputStream
+
+  out.write("""{ "type": "ExecCommand", "commandLine": "exit" }""".getBytes("utf-8"))
+  out.write(delimiter.toInt)
+  out.flush
+
+  val baseDirectory = new File(args(0))
+  IO.write(baseDirectory / "ok.txt", "ok")
+
+  def getConnection: Socket =
+    try {
+      new Socket(InetAddress.getByName(host), port)
+    } catch {
+      case _ =>
+        Thread.sleep(1000)
+        getConnection
+    }
+}

sbt/src/sbt-test/server/handshake/build.sbt

@@ -0,0 +1,13 @@
+lazy val runClient = taskKey[Unit]("")
+
+lazy val root = (project in file("."))
+  .settings(
+    scalaVersion := "2.12.3",
+    serverPort in Global := 5123,
+    libraryDependencies += "org.scala-sbt" %% "io" % "1.0.1",
+    runClient := (Def.taskDyn {
+      val b = baseDirectory.value
+      (bgRun in Compile).toTask(s""" $b""")
+    }).value
+  )
+ 

sbt/src/sbt-test/server/handshake/test

@@ -0,0 +1,6 @@
+> show serverPort
+> runClient
+-> shell
+
+$ sleep 1000
+$ exists ok.txt