Add test

Author: brkyvz

sql/core/src/test/scala/org/apache/spark/sql/execution/streaming/FileStreamSourceSuite.scala

@@ -17,9 +17,22 @@
 
 package org.apache.spark.sql.execution.streaming
 
+import java.io.File
+import java.net.URI
+
+import scala.util.Random
+
+import org.apache.hadoop.fs.{FileStatus, Path, RawLocalFileSystem}
+import org.scalatest.mock.MockitoSugar
+
 import org.apache.spark.SparkFunSuite
+import org.apache.spark.sql.execution.streaming.ExistsThrowsExceptionFileSystem._
+import org.apache.spark.sql.test.SharedSQLContext
+import org.apache.spark.sql.types.StructType
 
-class FileStreamSourceSuite extends SparkFunSuite {
+class FileStreamSourceSuite extends SparkFunSuite
+  with SharedSQLContext
+  with MockitoSugar {
 
   import FileStreamSource._
 
@@ -73,4 +86,41 @@ class FileStreamSourceSuite extends SparkFunSuite {
     assert(map.isNewFile(FileEntry("b", 10)))
   }
 
+  testWithUninterruptibleThread("do not recheck that files exist during getBatch") {
+    withTempDir { temp =>
+      spark.conf.set(
+        s"fs.$scheme.impl",
+        classOf[ExistsThrowsExceptionFileSystem].getName)
+      // add the metadata entries as a pre-req
+      val dir = new File(temp, "dir") // use non-existent directory to test whether log make the dir
+      val metadataLog = new HDFSMetadataLog[Array[FileEntry]](spark, dir.getAbsolutePath)
+      assert(metadataLog.add(0, Array(FileEntry(s"$scheme:///file1", 100L))))
+
+      val newSource = new FileStreamSource(spark, s"$scheme:///", "parquet", StructType(Nil),
+        dir.getAbsolutePath, Map.empty)
+      // this method should throw an exception if `fs.exists` is called during resolveRelation
+      newSource.getBatch(None, LongOffset(1))
+    }
+  }
+}
+
+/** FakeFileSystem to test fallback of the HDFSMetadataLog from FileContext to FileSystem API */
+class ExistsThrowsExceptionFileSystem extends RawLocalFileSystem {
+  override def getUri: URI = {
+    URI.create(s"$scheme:///")
+  }
+
+  override def exists(f: Path): Boolean = {
+    throw new IllegalArgumentException("Exists shouldn't have been called!")
+  }
+
+  override def listStatus(file: Path): Array[FileStatus] = {
+    val emptyFile = new FileStatus()
+    emptyFile.setPath(file)
+    Array(emptyFile)
+  }
+}
+
+object ExistsThrowsExceptionFileSystem {
+  val scheme = s"FileStreamSourceSuite${math.abs(Random.nextInt)}fs"
 }