Prompt silently if the output is redirected.

This fixes #159.

* Problem 1 is not solved: There still be no visible prompt if the
  output is redirected and that may be misinterpreted as a hanging
  process
* Problem 2 is solved: Neither the prompt not username and password
  appear in the output if it is redirected.
* Problem 3 is solved: TTY Echo is turned off earlier, so that one
  can start typing the password without having to fear it appearing
  in cleartext on the screen. Anything typed before we actually prompt
  is buffered and processed then, so it is totally fine now to type
  the password and enter as soon as the process is started.

Author: sherfert

cypher-shell/src/integration-test/java/org/neo4j/shell/MainIntegrationTest.java

@@ -1,5 +1,6 @@
 package org.neo4j.shell;
 
+import org.junit.Before;
 import org.junit.Test;
 import org.neo4j.shell.cli.CliArgs;
 import org.neo4j.shell.log.AnsiLogger;
@@ -16,39 +17,47 @@
 
 public class MainIntegrationTest {
 
-    @Test
-    public void connectInteractivelyPromptsOnWrongAuthentication() throws Exception {
+    private String inputString = String.format( "neo4j%nneo%n" );
+    private ByteArrayOutputStream baos;
+    private ConnectionConfig connectionConfig;
+    private CypherShell shell;
+    private Main main;
+
+    @Before
+    public void setup() {
         // given
-        // what the user inputs when prompted
-        String inputString = String.format( "neo4j%nneo%n" );
-        InputStream inputStream = new ByteArrayInputStream(inputString.getBytes());
+        InputStream inputStream = new ByteArrayInputStream( inputString.getBytes() );
 
-        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        PrintStream ps = new PrintStream(baos);
+        baos = new ByteArrayOutputStream();
+        PrintStream ps = new PrintStream( baos );
 
-        Main main = new Main(inputStream, ps);
+        main = new Main( inputStream, ps );
 
         CliArgs cliArgs = new CliArgs();
         cliArgs.setUsername("", "");
         cliArgs.setPassword( "", "" );
 
         Logger logger = new AnsiLogger(cliArgs.getDebugMode());
         PrettyConfig prettyConfig = new PrettyConfig(cliArgs);
-        ConnectionConfig connectionConfig = new ConnectionConfig(
+        connectionConfig = new ConnectionConfig(
                 cliArgs.getScheme(),
                 cliArgs.getHost(),
                 cliArgs.getPort(),
                 cliArgs.getUsername(),
                 cliArgs.getPassword(),
                 cliArgs.getEncryption());
 
-        CypherShell shell = new CypherShell(logger, prettyConfig);
+        shell = new CypherShell(logger, prettyConfig);
+    }
 
+
+    @Test
+    public void promptsOnWrongAuthenticationIfInteractive() throws Exception {
         // when
         assertEquals("", connectionConfig.username());
         assertEquals("", connectionConfig.password());
 
-        main.connectMaybeInteractively(shell, connectionConfig, true);
+        main.connectMaybeInteractively(shell, connectionConfig, true, true);
 
         // then
         // should be connected
@@ -60,4 +69,23 @@ public void connectInteractivelyPromptsOnWrongAuthentication() throws Exception
         String out = baos.toString();
         assertEquals( String.format( "username: neo4j%npassword: ***%n" ), out );
     }
+
+    @Test
+    public void promptsSilentlyOnWrongAuthenticationIfOutputRedirected() throws Exception {
+        // when
+        assertEquals("", connectionConfig.username());
+        assertEquals("", connectionConfig.password());
+
+        main.connectMaybeInteractively(shell, connectionConfig, true, false);
+
+        // then
+        // should be connected
+        assertTrue(shell.isConnected());
+        // should have prompted silently and set the username and password
+        assertEquals("neo4j", connectionConfig.username());
+        assertEquals("neo", connectionConfig.password());
+
+        String out = baos.toString();
+        assertEquals( "", out );
+    }
 }

cypher-shell/src/main/java/org/neo4j/shell/Main.java

@@ -5,7 +5,6 @@
 import org.neo4j.shell.build.Build;
 import org.neo4j.shell.cli.CliArgHelper;
 import org.neo4j.shell.cli.CliArgs;
-import org.neo4j.shell.cli.Format;
 import org.neo4j.shell.commands.CommandHelper;
 import org.neo4j.shell.exception.CommandException;
 import org.neo4j.shell.log.AnsiLogger;
@@ -15,9 +14,11 @@
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.io.PrintStream;
 
 import static org.neo4j.shell.ShellRunner.isInputInteractive;
+import static org.neo4j.shell.ShellRunner.isOutputInteractive;
 
 public class Main {
     static final String NEO_CLIENT_ERROR_SECURITY_UNAUTHORIZED = "Neo.ClientError.Security.Unauthorized";
@@ -72,7 +73,7 @@ void startShell(@Nonnull CliArgs cliArgs) {
         try {
             CypherShell shell = new CypherShell(logger, prettyConfig);
             // Can only prompt for password if input has not been redirected
-            connectMaybeInteractively(shell, connectionConfig, isInputInteractive());
+            connectMaybeInteractively(shell, connectionConfig, isInputInteractive(), isOutputInteractive());
 
             // Construct shellrunner after connecting, due to interrupt handling
             ShellRunner shellRunner = ShellRunner.getShellRunner(cliArgs, shell, logger, connectionConfig);
@@ -92,9 +93,20 @@ void startShell(@Nonnull CliArgs cliArgs) {
     /**
      * Connect the shell to the server, and try to handle missing passwords and such
      */
-    void connectMaybeInteractively(@Nonnull CypherShell shell, @Nonnull ConnectionConfig connectionConfig,
-                                   boolean interactively)
+    void connectMaybeInteractively(@Nonnull CypherShell shell,
+                                   @Nonnull ConnectionConfig connectionConfig,
+                                   boolean inputInteractive,
+                                   boolean outputInteractive)
             throws Exception {
+
+        OutputStream outputStream = outputInteractive ? out : new ThrowawayOutputStream();
+
+        ConsoleReader consoleReader = new ConsoleReader(in, outputStream);
+        // Disable expansion of bangs: !
+        consoleReader.setExpandEvents(false);
+        // Ensure Reader does not handle user input for ctrl+C behaviour
+        consoleReader.setHandleUserInterrupt(false);
+
         try {
             shell.connect(connectionConfig);
         } catch (AuthenticationException e) {
@@ -103,19 +115,24 @@ void connectMaybeInteractively(@Nonnull CypherShell shell, @Nonnull ConnectionCo
                 throw e;
             }
             // else need to prompt for username and password
-            if (interactively) {
+            if (inputInteractive) {
                 if (connectionConfig.username().isEmpty()) {
-                    connectionConfig.setUsername(promptForNonEmptyText("username", null));
+                    String username = outputInteractive ?
+                                      promptForNonEmptyText("username", consoleReader, null) :
+                                      promptForText("username", consoleReader, null);
+                    connectionConfig.setUsername(username);
                 }
                 if (connectionConfig.password().isEmpty()) {
-                    connectionConfig.setPassword(promptForText("password", '*'));
+                    connectionConfig.setPassword(promptForText("password", consoleReader, '*'));
                 }
                 // try again
                 shell.connect(connectionConfig);
             } else {
                 // Can't prompt because input has been redirected
                 throw e;
             }
+        } finally {
+            consoleReader.close();
         }
     }
 
@@ -129,40 +146,41 @@ void connectMaybeInteractively(@Nonnull CypherShell shell, @Nonnull ConnectionCo
      *         in case of errors
      */
     @Nonnull
-    private String promptForNonEmptyText(@Nonnull String prompt, @Nullable Character mask) throws Exception {
-        String text = promptForText(prompt, mask);
+    private String promptForNonEmptyText(@Nonnull String prompt, @Nonnull ConsoleReader consoleReader, @Nullable Character mask) throws Exception {
+        String text = promptForText(prompt, consoleReader, mask);
         if (!text.isEmpty()) {
             return text;
         }
-        out.println(prompt + " cannot be empty");
-        out.println();
-        return promptForNonEmptyText(prompt, mask);
+        consoleReader.println( prompt + " cannot be empty" );
+        consoleReader.println();
+        return promptForNonEmptyText(prompt, consoleReader, mask);
     }
 
     /**
      * @param prompt
      *         to display to the user
      * @param mask
      *         single character to display instead of what the user is typing, use null if text is not secret
+     * @param consoleReader
+     *         the reader
      * @return the text which was entered
      * @throws Exception
      *         in case of errors
      */
     @Nonnull
-    private String promptForText(@Nonnull String prompt, @Nullable Character mask) throws Exception {
-        String line;
-        ConsoleReader consoleReader = new ConsoleReader(in, out);
-        // Disable expansion of bangs: !
-        consoleReader.setExpandEvents(false);
-        // Ensure Reader does not handle user input for ctrl+C behaviour
-        consoleReader.setHandleUserInterrupt(false);
-        line = consoleReader.readLine(prompt + ": ", mask);
-        consoleReader.close();
-
+    private String promptForText(@Nonnull String prompt, @Nonnull ConsoleReader consoleReader, @Nullable Character mask) throws Exception {
+        String line = consoleReader.readLine(prompt + ": ", mask);
         if (line == null) {
             throw new CommandException("No text could be read, exiting...");
         }
 
         return line;
     }
+
+    private static class ThrowawayOutputStream extends OutputStream {
+        @Override
+        public void write( int b )
+        {
+        }
+    }
 }