diff -r 3739e9a5b6b5 -r 5f63af8f9d7f test/langtools/jdk/jshell/ToolEnablePreviewTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/langtools/jdk/jshell/ToolEnablePreviewTest.java	Mon Apr 23 09:01:03 2018 -0700
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8199193
+ * @summary Tests for the --enable-preview option
+ * @run testng ToolEnablePreviewTest
+ */
+
+import org.testng.annotations.Test;
+
+import static org.testng.Assert.assertTrue;
+
+public class ToolEnablePreviewTest extends ReplToolTesting {
+
+    @Test
+    public void testOptionDebug() {
+        String release = System.getProperty("java.specification.version");
+        test(
+                (a) -> assertCommand(a, "/debug b",
+                        "RemoteVM Options: []\n"
+                        + "Compiler options: []"),
+                (a) -> assertCommand(a, "/env --enable-preview",
+                        "|  Setting new options and restoring state."),
+                (a) -> assertCommandCheckOutput(a, "/debug b", s -> {
+                    assertTrue(s.contains("RemoteVM Options: [--enable-preview]"));
+                    assertTrue(s.contains("Compiler options: [-source, " + release + ", --enable-preview]")
+                            || s.contains("Compiler options: [--enable-preview, -source, " + release + "]"),
+                            "\nExpected -- " + "Compiler options: [-source, " + release + ", --enable-preview]"
+                            + "\nOr -- " + "Compiler options: [--enable-preview, -source, " + release + "]"
+                            + "\nBut got -- " + s);
+                })
+        );
+    }
+
+    @Test
+    public void testCommandLineFlag() {
+        String release = System.getProperty("java.specification.version");
+        test(new String[] {"--enable-preview"},
+                (a) -> assertCommandCheckOutput(a, "/debug b", s -> {
+                    assertTrue(s.contains("RemoteVM Options: [--enable-preview]"));
+                    assertTrue(s.contains("Compiler options: [-source, " + release + ", --enable-preview]")
+                            || s.contains("Compiler options: [--enable-preview, -source, " + release + "]"),
+                            "\nExpected -- " + "Compiler options: [-source, " + release + ", --enable-preview]"
+                            + "\nOr -- " + "Compiler options: [--enable-preview, -source, " + release + "]"
+                            + "\nBut got -- " + s);
+                })
+        );
+    }
+
+    @Test
+    public void testCompilerTestFlagEnv() {
+        test(new String[] {"-C", "-XDforcePreview"},
+                (a) -> assertCommandOutputContains(a, "Function<Integer,Integer> f = i -> i + i",
+                        "Error", "preview feature"),
+                (a) -> assertCommand(a, "/env --enable-preview",
+                        "|  Setting new options and restoring state."),
+                (a) -> assertCommandOutputContains(a, "Function<Integer,Integer> f = i -> i + i",
+                        "f ==> ")
+        );
+    }
+
+    @Test
+    public void testCompilerTestFlag() {
+        test(new String[] {"-C", "-XDforcePreview", "--enable-preview"},
+                (a) -> assertCommandOutputContains(a, "Function<Integer,Integer> f = i -> i + i",
+                        "f ==> "),
+                (a) -> assertCommandOutputContains(a, "f.apply(2)", "==> 4")
+        );
+    }
+
+}