Add a "shell" pseudo-command to nomulus tool

Add the "shell" command which lets you run multiple other command in a single
session, sparing you the initialization costs for all but the first of them.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=188712815

java/google/registry/tools/CommandRunner.java

@@ -0,0 +1,24 @@
+// Copyright 2018 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;
+
+/**
+ * Interface for things that run commands.
+ *
+ * <p>This exists only to allow us to test ShellCommand.
+ */
+interface CommandRunner {
+  public void run(String[] args) throws Exception;
+}

java/google/registry/tools/RegistryCli.java

@@ -35,7 +35,7 @@ import org.bouncycastle.jce.provider.BouncyCastleProvider;
 
 /** Container class to create and run remote commands against a Datastore instance. */
 @Parameters(separators = " =", commandDescription = "Command-line interface to the registry")
-final class RegistryCli {
+final class RegistryCli implements AutoCloseable, CommandRunner {
 
   @Parameter(
       names = {"-e", "--environment"},
@@ -57,33 +57,54 @@ final class RegistryCli {
   @ParametersDelegate
   private LoggingParameters loggingParams = new LoggingParameters();
 
-  // The <? extends Class<? extends Command>> wildcard looks a little funny, but is needed so that
-  // we can accept maps with value types that are subtypes of Class<? extends Command> rather than
-  // literally that type.  For more explanation, see:
-  //   http://www.angelikalanger.com/GenericsFAQ/FAQSections/TypeArguments.html#FAQ104
-  void run(
-      String programName,
-      String[] args,
-      ImmutableMap<String, ? extends Class<? extends Command>> commands) throws Exception {
+  // These are created lazily on first use.
+  private AppEngineConnection connection;
+  private RemoteApiInstaller installer;
+
+
+  Map<String, Command> commandInstances;
+  Map<String, ? extends Class<? extends Command>> commands;
+  JCommander jcommander;
+
+  RegistryCli(
+      String programName, ImmutableMap<String, ? extends Class<? extends Command>> commands) {
+    this.commands = commands;
+
     Security.addProvider(new BouncyCastleProvider());
-    JCommander jcommander = new JCommander(this);
+    jcommander = new JCommander(this);
     jcommander.addConverterFactory(new ParameterFactory());
     jcommander.setProgramName(programName);
 
     // Store the instances of each Command class here so we can retrieve the same one for the
     // called command later on.  JCommander could have done this for us, but it doesn't.
-    Map<String, Command> commandInstances = new HashMap<>();
+    commandInstances = new HashMap<>();
 
     HelpCommand helpCommand = new HelpCommand(jcommander);
     jcommander.addCommand("help", helpCommand);
     commandInstances.put("help", helpCommand);
 
-    for (Map.Entry<String, ? extends Class<? extends Command>> entry : commands.entrySet()) {
-      Command command = entry.getValue().getDeclaredConstructor().newInstance();
-      jcommander.addCommand(entry.getKey(), command);
-      commandInstances.put(entry.getKey(), command);
-    }
+    // Add the shell command.
+    ShellCommand shellCommand = new ShellCommand(System.in, this);
+    jcommander.addCommand("shell", shellCommand);
+    commandInstances.put("shell", shellCommand);
 
+    try {
+      for (Map.Entry<String, ? extends Class<? extends Command>> entry : commands.entrySet()) {
+        Command command = entry.getValue().getDeclaredConstructor().newInstance();
+        jcommander.addCommand(entry.getKey(), command);
+        commandInstances.put(entry.getKey(), command);
+      }
+    } catch (ReflectiveOperationException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  // The <? extends Class<? extends Command>> wildcard looks a little funny, but is needed so that
+  // we can accept maps with value types that are subtypes of Class<? extends Command> rather than
+  // literally that type.  For more explanation, see:
+  //   http://www.angelikalanger.com/GenericsFAQ/FAQSections/TypeArguments.html#FAQ104
+  @Override
+  public void run(String[] args) throws Exception {
     try {
       jcommander.parse(args);
     } catch (ParameterException e) {
@@ -127,6 +148,14 @@ final class RegistryCli {
     }
   }
 
+  @Override
+  public void close() {
+    if (installer != null) {
+      installer.uninstall();
+      installer = null;
+    }
+  }
+
   private void runCommand(Command command) throws Exception {
     // Create the main component and use it to inject the command class.
     RegistryToolComponent component = DaggerRegistryToolComponent.builder()
@@ -142,31 +171,35 @@ final class RegistryCli {
     }
 
     // Get the App Engine connection, advise the user if they are not currently logged in..
-    AppEngineConnection connection = component.appEngineConnection();
+    if (connection == null) {
+      connection = component.appEngineConnection();
+    }
 
     if (command instanceof ServerSideCommand) {
       ((ServerSideCommand) command).setConnection(connection);
     }
 
     // RemoteApiCommands need to have the remote api installed to work.
-    RemoteApiInstaller installer = new RemoteApiInstaller();
-    RemoteApiOptions options = new RemoteApiOptions();
-    options.server(connection.getServer().getHost(), connection.getServer().getPort());
-    if (connection.isLocalhost()) {
-      // Use dev credentials for localhost.
-      options.useDevelopmentServerCredential();
-    } else {
-      options.useApplicationDefaultCredential();
+    if (installer == null) {
+      installer = new RemoteApiInstaller();
+      RemoteApiOptions options = new RemoteApiOptions();
+      options.server(connection.getServer().getHost(), connection.getServer().getPort());
+      if (connection.isLocalhost()) {
+        // Use dev credentials for localhost.
+        options.useDevelopmentServerCredential();
+      } else {
+        options.useApplicationDefaultCredential();
+      }
+      installer.install(options);
     }
-    installer.install(options);
 
     // Ensure that all entity classes are loaded before command code runs.
     ObjectifyService.initOfy();
 
-    try {
-      command.run();
-    } finally {
-      installer.uninstall();
-    }
+    command.run();
+  }
+
+  void setEnvironment(RegistryToolEnvironment environment) {
+    this.environment = environment;
   }
 }

java/google/registry/tools/RegistryTool.java

@@ -132,6 +132,8 @@ public final class RegistryTool {
 
   public static void main(String[] args) throws Exception {
     RegistryToolEnvironment.parseFromArgs(args).setup();
-    new RegistryCli().run("nomulus", args, COMMAND_MAP);
+    try (RegistryCli cli = new RegistryCli("nomulus", COMMAND_MAP)) {
+      cli.run(args);
+    }
   }
 }

java/google/registry/tools/ShellCommand.java

@@ -0,0 +1,93 @@
+// Copyright 2018 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 java.nio.charset.StandardCharsets.US_ASCII;
+
+import com.beust.jcommander.Parameters;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableList;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.StreamTokenizer;
+import java.io.StringReader;
+
+/**
+ * Implements a tiny shell interpreter for the nomulus tool.
+ *
+ * <p>Parses a very simple command grammar. Tokens are either whitespace delimited words or
+ * double-quoted strings.
+ */
+@Parameters(commandDescription = "Run an interactive shell")
+public class ShellCommand implements Command {
+
+  private final CommandRunner runner;
+  private final BufferedReader lineReader;
+
+  ShellCommand(InputStream in, CommandRunner runner) {
+    this.runner = runner;
+    this.lineReader = new BufferedReader(new InputStreamReader(in, US_ASCII));
+  }
+
+  /** Run the shell until the user presses "Ctrl-D". */
+  @Override
+  public void run() {
+    String line;
+    while ((line = getLine()) != null) {
+      String[] lineArgs = parseCommand(line);
+      try {
+        runner.run(lineArgs);
+      } catch (Exception e) {
+        System.err.println("Got an exception:\n" + e);
+      }
+    }
+  }
+
+  private String getLine() {
+    if (System.console() != null) {
+      System.err.print("nom> ");
+    }
+    try {
+      return lineReader.readLine();
+    } catch (IOException e) {
+      return null;
+    }
+  }
+
+  @VisibleForTesting
+  static String[] parseCommand(String line) {
+    ImmutableList.Builder<String> resultBuilder = new ImmutableList.Builder<>();
+
+    // Create a tokenizer, make everything word characters except quoted strings and unprintable
+    // ascii chars and space (just treat them all as whitespace).
+    StreamTokenizer tokenizer = new StreamTokenizer(new StringReader(line));
+    tokenizer.resetSyntax();
+    tokenizer.whitespaceChars(0, ' ');
+    tokenizer.wordChars('!', '~');
+    tokenizer.quoteChar('"');
+
+    try {
+      while (tokenizer.nextToken() != StreamTokenizer.TT_EOF) {
+        resultBuilder.add(tokenizer.sval);
+      }
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+
+    return resultBuilder.build().toArray(new String[0]);
+  }
+}

javatests/google/registry/tools/RegistryToolTest.java

@@ -90,8 +90,8 @@ public class RegistryToolTest {
   /**
    * Gets the set of all non-abstract classes implementing the {@link Command} interface (abstract
    * class and interface subtypes of Command aren't expected to have cli commands). Note that this
-   * also filters out HelpCommand, which has special handling in {@link RegistryCli} and isn't in
-   * the command map.
+   * also filters out HelpCommand and ShellCommand, which have special handling in {@link
+   * RegistryCli} and aren't in the command map.
    *
    * @throws IOException if reading the classpath resources fails.
    */
@@ -105,7 +105,8 @@ public class RegistryToolTest {
       if (Command.class.isAssignableFrom(clazz)
           && !Modifier.isAbstract(clazz.getModifiers())
           && !Modifier.isInterface(clazz.getModifiers())
-          && !clazz.equals(HelpCommand.class)) {
+          && !clazz.equals(HelpCommand.class)
+          && !clazz.equals(ShellCommand.class)) {
         builder.add((Class<? extends Command>) clazz);
       }
     }

javatests/google/registry/tools/ShellCommandTest.java

@@ -0,0 +1,68 @@
+// Copyright 2018 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 com.google.common.truth.Truth.assertThat;
+import static java.nio.charset.StandardCharsets.US_ASCII;
+import static org.mockito.Mockito.mock;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import java.io.ByteArrayInputStream;
+import java.util.ArrayList;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class ShellCommandTest {
+
+  CommandRunner cli = mock(CommandRunner.class);
+
+  public ShellCommandTest() {}
+
+  @Test
+  public void testParsing() {
+    assertThat(ShellCommand.parseCommand("foo bar 123 baz+ // comment \"string data\""))
+        .isEqualTo(new String[] {"foo", "bar", "123", "baz+", "//", "comment", "string data"});
+    assertThat(ShellCommand.parseCommand("\"got \\\" escapes?\""))
+        .isEqualTo(new String[] {"got \" escapes?"});
+    assertThat(ShellCommand.parseCommand("")).isEqualTo(new String[0]);
+  }
+
+  @Test
+  public void testCommandProcessing() {
+    String testData = "test1 foo bar\ntest2 foo bar\n";
+    ImmutableMap<String, Class<? extends Command>> commandMap = ImmutableMap.of();
+    MockCli cli = new MockCli();
+    ShellCommand shellCommand =
+        new ShellCommand(new ByteArrayInputStream(testData.getBytes(US_ASCII)), cli);
+    shellCommand.run();
+    assertThat(cli.calls)
+        .containsExactly(
+            ImmutableList.of("test1", "foo", "bar"), ImmutableList.of("test2", "foo", "bar"))
+        .inOrder();
+  }
+
+  static class MockCli implements CommandRunner {
+    public ArrayList<ImmutableList<String>> calls = new ArrayList<>();
+
+    @Override
+    public void run(String[] args)
+        throws Exception {
+      calls.add(ImmutableList.copyOf(args));
+    }
+  }
+}