Cleanup ExecRemote code:

* Replace action extension with simple closure composition
* Separate remote and local execution

buildSrc/plugins/src/main/groovy/org/jetbrains/kotlin/ExecRemote.groovy

@@ -22,74 +22,81 @@ import org.gradle.process.ExecResult
 import org.gradle.process.ExecSpec
 import org.gradle.util.ConfigureUtil
 
-// This class provides process.execRemote -- a drop-in replacement for process.exec .
-// If we provide -Premote=user@host the binaries are executed on a remote host
-// If we omit -Premote then the binary is executed locally as usual.
+import java.nio.file.Paths
+import java.util.function.Function
 
+/**
+ * This class provides process.execRemote -- a drop-in replacement for process.exec.
+ * If we provide -Premote=user@host the binaries are executed on a remote host
+ * If we omit -Premote then the binary is executed locally as usual.
+ */
 class ExecRemote {
 
     private final Project project
-    private final String remote = null
-    private final String remoteDir = null
+    private final Function<Closure<? super ExecSpec>, ExecResult> executor
 
     ExecRemote(Project project) {
         this.project = project
-         if (project.hasProperty('remote')) {
-             remote = project.ext.remote
-             remoteDir = uniqSessionName()
-             createRemoteDir()
-         }
-    }
-
-    private String uniqSessionName() {
-        def date = new Date().format('yyyyMMddHHmmss')
-        return project.ext.remoteRoot + File.createTempFile(System.properties['user.name'], "_" + date)
-    }
-
-    private createRemoteDir() {
-        project.exec {
-             commandLine('ssh', remote, 'mkdir', '-p', remoteDir)
+        if (project.hasProperty('remote')) {
+            def remote = project.property('remote') as String
+            executor = new SSHExecutor(remote)
+        } else {
+            executor = { project.exec(ConfigureUtil.configureUsing(it)) }
         }
     }
 
-    private upload(String fileName) {
-        project.exec {
-            commandLine('scp', fileName, "${remote}:${remoteDir}")
-        }
+    ExecResult execRemote(Action<? super ExecSpec> action) {
+        project.exec(action)
     }
 
-    private cleanup(String fileName) {
-        println "Remove ${remote}:${fileName}"
-        project.exec {
-            commandLine('ssh', remote, 'rm', fileName )
-        }
+    ExecResult execRemote(Closure<? super ExecSpec> closure) {
+        this.executor.apply(closure)
     }
 
-    public ExecResult execRemote(Action<? super ExecSpec> action) {
-        String execFile
-        Action<? super ExecSpec> extendedAction = new Action<ExecSpec>() {
-            @Override
-            void execute(ExecSpec execSpec) {
-                action.execute(execSpec)
+    private class SSHExecutor implements Function<Closure<? super ExecSpec>, ExecResult> {
+        private final String remote
+        private final String remoteDir
 
-                if (remote == null) return
+        SSHExecutor(String remote) {
+            this.remote = remote
+            this.remoteDir = uniqueSessionName()
+            createRemoteDir()
+        }
 
-                execSpec.with {
-                    upload(getExecutable())
-                    executable = "$remoteDir/${new File(executable).name}"
-                    execFile = executable
-                    if (project.hasProperty('remote')) {
-                        commandLine = ['/usr/bin/ssh', remote] + commandLine
-                    }
-                }
+        @Override
+        ExecResult apply(Closure<? super ExecSpec> closure) {
+            String execFile
+            def execResult = project.exec closure >> {
+                upload(executable)
+                execFile = executable = "$remoteDir/${new File(executable).name}"
+                commandLine = ['/usr/bin/ssh', remote] + commandLine
+            }
+            if (execFile != null) cleanup(execFile)
+            return execResult
+        }
+
+        private String uniqueSessionName() {
+            def date = new Date().format('yyyyMMddHHmmss')
+            Paths.get(project.ext.remoteRoot.toString(), "tmp",
+                    System.properties['user.name'].toString() + "_" + date).toString()
+        }
+
+        private createRemoteDir() {
+            project.exec {
+                commandLine('ssh', remote, 'mkdir', '-p', remoteDir)
             }
         }
-        def execResult = project.exec(extendedAction)
-        if (execFile != null) cleanup(execFile)
-        return execResult
-    }
 
-    public ExecResult execRemote(Closure closure) {
-        return this.execRemote(ConfigureUtil.configureUsing(closure));
+        private upload(String fileName) {
+            project.exec {
+                commandLine('scp', fileName, "${remote}:${remoteDir}")
+            }
+        }
+
+        private cleanup(String fileName) {
+            project.exec {
+                commandLine('ssh', remote, 'rm', fileName)
+            }
+        }
     }
 }