Add a PathConvertible for URI (#142)

Only the "file" protocol is supported. Other protocols and unsupported URIs will throw a `IllegalArgumentException`.

Pull request: #142

Author: ckipp01

os/src/Path.scala

@@ -1,5 +1,8 @@
 package os
 
+import java.net.URI
+import java.nio.file.Paths
+
 import collection.JavaConverters._
 import scala.language.implicitConversions
 
@@ -501,12 +504,21 @@ sealed trait PathConvertible[T] {
 
 object PathConvertible {
   implicit object StringConvertible extends PathConvertible[String] {
-    def apply(t: String) = java.nio.file.Paths.get(t)
+    def apply(t: String) = Paths.get(t)
   }
   implicit object JavaIoFileConvertible extends PathConvertible[java.io.File] {
-    def apply(t: java.io.File) = java.nio.file.Paths.get(t.getPath)
+    def apply(t: java.io.File) = Paths.get(t.getPath)
   }
   implicit object NioPathConvertible extends PathConvertible[java.nio.file.Path] {
     def apply(t: java.nio.file.Path) = t
   }
+  implicit object UriPathConvertible extends PathConvertible[URI] {
+    def apply(uri: URI) = uri.getScheme() match {
+      case "file" => Paths.get(uri)
+      case uriType =>
+        throw new IllegalArgumentException(
+          s"""os.Path can only be created from a "file" URI scheme, but found "${uriType}""""
+        )
+    }
+  }
 }

os/test/src/PathTests.scala

@@ -4,6 +4,7 @@ import java.nio.file.Paths
 
 import os._
 import utest.{assert => _, _}
+import java.net.URI
 object PathTests extends TestSuite{
   val tests = Tests {
     test("Basic"){
@@ -19,6 +20,20 @@ object PathTests extends TestSuite{
           assert(rel/"omg" == RelPath(Paths.get("omg")))
           assert(sub/"omg" == SubPath(Paths.get("omg")))
 
+          // URI to os.Path
+          assert(root / "omg" == Path(Paths.get("/omg").toUri()))
+
+          // We only support file schemes like above, but nothing else
+          val httpUri = URI.create(
+            "https://[email protected]:123/forum/questions/?tag=networking&order=newest#top"
+          )
+          val ldapUri = URI.create(
+            "ldap://[2001:db8::7]/c=GB?objectClass?one"
+          )
+          intercept[IllegalArgumentException](Path(httpUri))
+          intercept[IllegalArgumentException](Path(ldapUri))
+
+
           // os.Path to String
           assert((root/"omg").toString == "/omg")
           assert((rel/"omg").toString == "omg")