Add a getReservedList command (#1041)

* Add a getReservedList command

* add tests

* Remove multiple lists parameter

* print error to stderr

core/src/test/java/google/registry/tools/GetReservedListCommandTest.java

@@ -0,0 +1,59 @@
+// Copyright 2021 The Nomulus Authors. All Rights Reserved.
+//
+// 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 google.registry.tools;
+
+import static google.registry.testing.DatabaseHelper.persistReservedList;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import com.beust.jcommander.ParameterException;
+import google.registry.testing.DualDatabaseTest;
+import google.registry.testing.TestOfyAndSql;
+import org.junit.jupiter.api.BeforeEach;
+
+@DualDatabaseTest
+public class GetReservedListCommandTest extends CommandTestCase<GetReservedListCommand> {
+
+  private static final String BASE_LIST_CONTENTS =
+      "atlanta,RESERVED_FOR_SPECIFIC_USE # comment\n"
+          + "boston,RESERVED_FOR_SPECIFIC_USE\n"
+          + "chicago,FULLY_BLOCKED # another comment\n"
+          + "dallas,RESERVED_FOR_SPECIFIC_USE # cool city\n"
+          + "elpaso,RESERVED_FOR_SPECIFIC_USE\n"
+          + "fairbanks,RESERVED_FOR_ANCHOR_TENANT # alaska\n"
+          + "greensboro,RESERVED_FOR_SPECIFIC_USE\n";
+
+  @BeforeEach
+  void beforeEach() {
+    persistReservedList("tld_reserved-terms", BASE_LIST_CONTENTS);
+  }
+
+  @TestOfyAndSql
+  void testSuccess_list() throws Exception {
+    runCommand("-n=tld_reserved-terms");
+    assertStdoutIs(BASE_LIST_CONTENTS);
+  }
+
+  @TestOfyAndSql
+  void testFailure_nonexistent() throws Exception {
+    runCommand("-n=nonexistent");
+    assertStdoutIs("");
+    assertInStderr("No list found with name nonexistent.\n");
+  }
+
+  @TestOfyAndSql
+  void testFailure_noArgs() {
+    assertThrows(ParameterException.class, this::runCommand);
+  }
+}