add the FileSystemSpec trait

test/src/main/scala/com/amadeus/dataio/test/FileSystemSpec.scala

@@ -0,0 +1,36 @@
+package com.amadeus.dataio.test
+
+import org.apache.hadoop.conf.Configuration
+import org.apache.hadoop.fs.{FileSystem, Path}
+import org.scalatest.{BeforeAndAfter, TestSuite}
+
+/**
+ * Provides the Hadoop LocalFileSystem for tests needing direct access to an instance of FileSystem.
+ *
+ * Provides a dedicated instance initialized before each test and automatically closed after each test, providing as
+ * much isolation as possible between tests. It also deletes the dataio-test temporary directory (/tmp/dataio-test/) and
+ * sub-directories, before closing the FileSystem.
+ *
+ * e.g.
+ * {{{
+ *   class MyClassTest extends WordSpec with FileSystemSpec{
+ *      // provided by FileSystemSpec:
+ *      // fs: FileSystem
+ *      // val tmpPath: String = "file:///tmp/dataio-test/"
+ *   }
+ * }}}
+ */
+trait FileSystemSpec extends TestSuite with BeforeAndAfter {
+  val tmpPath = "file:///tmp/dataio-test/"
+
+  var fs: FileSystem = _
+
+  before {
+    fs = FileSystem.newInstance(new Configuration())
+  }
+
+  after {
+    fs.delete(new Path(tmpPath), true)
+    fs.close()
+  }
+}