Improve prompt

- Add newline to make multi-line statement formatting independent
of database name
- Substitute an absent database name for the default default name

Author: henriknyman

cypher-shell/src/integration-test/java/org/neo4j/shell/commands/CypherShellMultiDatabaseIntegrationTest.java

@@ -18,13 +18,12 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assume.assumeTrue;
 import static org.neo4j.driver.internal.messaging.request.MultiDatabaseUtil.ABSENT_DB_NAME;
+import static org.neo4j.shell.DatabaseManager.DEFAULT_DEFAULT_DB_NAME;
+import static org.neo4j.shell.DatabaseManager.SYSTEM_DB_NAME;
 import static org.neo4j.shell.Versions.majorVersion;
 
 public class CypherShellMultiDatabaseIntegrationTest
 {
-    private static final String SYSTEM_DB_NAME = "system";
-    private static final String DEFAULT_DB_NAME = "neo4j";
-
     @Rule
     public final ExpectedException thrown = ExpectedException.none();
 
@@ -62,7 +61,7 @@ public void switchingToSystemDatabaseWorks() throws CommandException {
     @Test
     public void switchingToSystemDatabaseAndBackToDefaultWorks() throws CommandException {
         useCommand.execute(SYSTEM_DB_NAME);
-        useCommand.execute(DEFAULT_DB_NAME);
+        useCommand.execute(DEFAULT_DEFAULT_DB_NAME);
 
         assertThat(linePrinter.output(), is(""));
     }

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

@@ -7,6 +7,9 @@
  */
 public interface DatabaseManager
 {
+    String DEFAULT_DEFAULT_DB_NAME = "neo4j";
+    String SYSTEM_DB_NAME = "system";
+
     void setActiveDatabase(String databaseName) throws CommandException;
 
     String getActiveDatabase();

cypher-shell/src/main/java/org/neo4j/shell/cli/InteractiveShellRunner.java

@@ -25,14 +25,17 @@
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import static org.neo4j.driver.internal.messaging.request.MultiDatabaseUtil.ABSENT_DB_NAME;
+import static org.neo4j.shell.DatabaseManager.DEFAULT_DEFAULT_DB_NAME;
+
 /**
  * A shell runner intended for interactive sessions where lines are input one by one and execution should happen
  * along the way.
  */
 public class InteractiveShellRunner implements ShellRunner, SignalHandler {
     static final String INTERRUPT_SIGNAL = "INT";
     private final static String freshPrompt = "> ";
-    private final static AnsiFormattedText continuationPrompt = AnsiFormattedText.s().bold().append("       ");
+    private final static AnsiFormattedText continuationPrompt = AnsiFormattedText.s().bold().append("  ");
     private final static String transactionPrompt = "# ";
     // Need to know if we are currently executing when catch Ctrl-C, needs to be atomic due to
     // being called from different thread
@@ -155,10 +158,21 @@ AnsiFormattedText getPrompt() {
             return continuationPrompt;
         }
 
+        String databaseName = databaseManager.getActiveDatabase();
+
+        // Substitute empty name for the default default-database-name
+        // For now we just use a hard-coded default name
+        // Ideally we would like to receive the actual name in the ResultSummary when we connect (in BoltStateHandler.reconnect())
+        // (If the user is an admin we could also query for the default database config value with:
+        //   "CALL dbms.listConfig() YIELD name, value WHERE name = "dbms.default_database" RETURN value"
+        //  but that does not work in general)
+        databaseName = ABSENT_DB_NAME.equals(databaseName) ? DEFAULT_DEFAULT_DB_NAME : databaseName;
+
         AnsiFormattedText prompt = AnsiFormattedText.s().bold()
                 .append(connectionConfig.username())
                 .append("@")
-                .append(databaseManager.getActiveDatabase())
+                .append(databaseName)
+                .appendNewLine()
                 .append(txHandler.isTransactionOpen()? transactionPrompt : freshPrompt);
         return prompt;
     }

cypher-shell/src/main/java/org/neo4j/shell/log/AnsiFormattedText.java

@@ -132,6 +132,15 @@ public AnsiFormattedText append(String s) {
         return this;
     }
 
+    /**
+     * Append a new line
+     * @return this
+     */
+    public AnsiFormattedText appendNewLine() {
+        pieces.add(new AnsiFormattedString(color, attributes, System.lineSeparator()));
+        return this;
+    }
+
     /**
      * Set formatting to bold. Note that this has no effect on strings already in the text.
      *

cypher-shell/src/main/java/org/neo4j/shell/state/BoltStateHandler.java

@@ -151,6 +151,7 @@ private void reconnect(boolean keepBookmark) {
 
         StatementResult run = session.run("RETURN 1");
         this.version = run.summary().server().version();
+        // It would be nice if we could also get the actual database name here, in the case where we used ABSENT_DB_NAME
         run.consume();
     }
 

cypher-shell/src/test/java/org/neo4j/shell/cli/InteractiveShellRunnerTest.java

@@ -34,6 +34,7 @@
 import java.util.List;
 import java.util.concurrent.atomic.AtomicReference;
 
+import static java.lang.String.format;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertEquals;
@@ -269,21 +270,21 @@ public void testPrompt() throws Exception {
         AnsiFormattedText prompt = runner.getPrompt();
 
         // then
-        assertEquals("myusername@mydb> ", prompt.plainString());
+        assertEquals( format("myusername@mydb%n> "), prompt.plainString());
 
         // when
         statementParser.parseMoreText("  \t \n   "); // whitespace
         prompt = runner.getPrompt();
 
         // then
-        assertEquals("myusername@mydb> ", prompt.plainString());
+        assertEquals( format("myusername@mydb%n> "), prompt.plainString());
 
         // when
         statementParser.parseMoreText("bla bla"); // non whitespace
         prompt = runner.getPrompt();
 
         // then
-        assertEquals("       ", prompt.plainString());
+        assertEquals("  ", prompt.plainString());
     }
 
     @Test
@@ -298,21 +299,21 @@ public void testPromptInTx() throws Exception {
         AnsiFormattedText prompt = runner.getPrompt();
 
         // then
-        assertEquals("myusername@mydb# ", prompt.plainString());
+        assertEquals(format("myusername@mydb%n# "), prompt.plainString());
 
         // when
         statementParser.parseMoreText("  \t \n   "); // whitespace
         prompt = runner.getPrompt();
 
         // then
-        assertEquals("myusername@mydb# ", prompt.plainString());
+        assertEquals(format("myusername@mydb%n# "), prompt.plainString());
 
         // when
         statementParser.parseMoreText("bla bla"); // non whitespace
         prompt = runner.getPrompt();
 
         // then
-        assertEquals("       ", prompt.plainString());
+        assertEquals("  ", prompt.plainString());
     }
 
     @Test