Merge pull request #2622 from armanbilge/feature/files-realpath

Implement Files#realPath

io/js/src/main/scala/fs2/io/file/FilesPlatform.scala

@@ -336,6 +336,9 @@ private[fs2] trait FilesCompanionPlatform {
     override def readRange(path: Path, chunkSize: Int, start: Long, end: Long): Stream[F, Byte] =
       readStream(path, chunkSize, Flags.Read)(_.setStart(start.toDouble).setEnd((end - 1).toDouble))
 
+    def realPath(path: Path): F[Path] =
+      F.fromPromise(F.delay(fsPromisesMod.realpath(path.toString))).map(Path(_))
+
     override def setFileTimes(
         path: Path,
         lastModified: Option[FiniteDuration],

io/jvm/src/main/scala/fs2/io/file/FilesPlatform.scala

@@ -302,6 +302,9 @@ private[file] trait FilesCompanionPlatform {
     def openFileChannel(channel: F[FileChannel]): Resource[F, FileHandle[F]] =
       Resource.make(channel)(ch => Sync[F].blocking(ch.close())).map(ch => FileHandle.make(ch))
 
+    def realPath(path: Path): F[Path] =
+      Sync[F].blocking(Path.fromNioPath(path.toNioPath.toRealPath()))
+
     def setFileTimes(
         path: Path,
         lastModified: Option[FiniteDuration],

io/shared/src/main/scala/fs2/io/file/Files.scala

@@ -270,6 +270,13 @@ sealed trait Files[F[_]] extends FilesPlatform[F] {
     */
   def readRange(path: Path, chunkSize: Int, start: Long, end: Long): Stream[F, Byte]
 
+  /** Returns the real path i.e. the actual location of `path`.
+    * The precise definition of this method is implementation dependent but in general
+    * it derives from this path, an absolute path that locates the same file as this path,
+    * but with name elements that represent the actual name of the directories and the file.
+    */
+  def realPath(path: Path): F[Path]
+
   /** Sets the last modified, last access, and creation time fields of the specified path.
     *
     * Times which are supplied as `None` are not modified. E.g., `setTimes(p, Some(t), Some(t), None, false)`