Add test for FileSystem caching

presto-hive/src/test/java/com/facebook/presto/hive/TestFileSystemCache.java

@@ -0,0 +1,56 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.facebook.presto.hive;
+
+import com.facebook.presto.hive.authentication.ImpersonatingHdfsAuthentication;
+import com.facebook.presto.hive.authentication.SimpleHadoopAuthentication;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.testng.annotations.Test;
+
+import java.io.IOException;
+
+import static org.testng.Assert.assertNotSame;
+import static org.testng.Assert.assertSame;
+
+public class TestFileSystemCache
+{
+    @Test
+    public void testFileSystemCache()
+            throws IOException
+    {
+        ImpersonatingHdfsAuthentication auth = new ImpersonatingHdfsAuthentication(new SimpleHadoopAuthentication());
+        HdfsEnvironment environment =
+                new HdfsEnvironment(
+                        new HiveHdfsConfiguration(new HdfsConfigurationUpdater(new HiveClientConfig())),
+                        new HiveClientConfig(),
+                        auth);
+        FileSystem fs1 = getFileSystem(environment, "user");
+        FileSystem fs2 = getFileSystem(environment, "user");
+        assertSame(fs1, fs2);
+
+        FileSystem fs3 = getFileSystem(environment, "other_user");
+        assertNotSame(fs1, fs3);
+
+        FileSystem fs4 = getFileSystem(environment, "other_user");
+        assertSame(fs3, fs4);
+    }
+
+    private FileSystem getFileSystem(HdfsEnvironment environment, String user)
+            throws IOException
+    {
+        return environment.getFileSystem(user, new Path("/"), new Configuration(false));
+    }
+}