Add nextAlphaStringMethod

community/random-values/src/main/java/org/neo4j/values/RandomValue.java

@@ -150,6 +150,25 @@ public TextValue nextDigitString( int minLength, int maxLength )
         return Values.utf8Value( bytes );
     }
 
+    public TextValue nextAlphaString( int minLength, int maxLength )
+    {
+        int length = intBetween( minLength, maxLength );
+        byte[] bytes = new byte[length];
+        for ( int i = 0; i < length; i++ )
+        {
+            if (random.nextBoolean() )
+            {
+                bytes[i] = (byte) intBetween( 'A', 'Z' );
+            }
+            else
+            {
+                bytes[i] = (byte) intBetween( 'a', 'z' );
+            }
+        }
+
+        return Values.utf8Value( bytes );
+    }
+
     private int intBetween( int min, int max )
     {
         return min + random.nextInt( max - min + 1 );

community/random-values/src/main/java/org/neo4j/values/UTF8Utils.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2002-2018 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.values;
+
+public class UTF8Utils
+{
+}

community/random-values/src/test/java/org/neo4j/values/RandomValueTest.java

@@ -25,6 +25,7 @@
 import java.util.HashSet;
 import java.util.Set;
 import java.util.function.Supplier;
+import java.util.stream.Collectors;
 
 import org.neo4j.values.storable.ByteValue;
 import org.neo4j.values.storable.DoubleValue;
@@ -162,21 +163,41 @@ public void nextNumberValue()
     @Test
     public void nextDigitString()
     {
-        Set<Character> seenDigits = new HashSet<>( Arrays.asList( '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' ) );
+        Set<Integer> seenDigits = "0123456789".chars().boxed().collect( Collectors.toSet() );
         for ( int i = 0; i < ITERATIONS; i++ )
         {
             TextValue textValue = randomValue.nextDigitString( 5, 10 );
             String asString = textValue.stringValue();
             for ( int j = 0; j < asString.length(); j++ )
             {
-                char ch = asString.charAt( j );
+                int ch = asString.charAt( j );
                 assertTrue( Character.isDigit( ch ));
                 seenDigits.remove( ch );
             }
         }
         assertThat( seenDigits, empty() );
     }
 
+    @Test
+    public void nextAlphaString()
+    {
+        Set<Integer> seenDigits = "ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvxyz".chars().boxed()
+                .collect( Collectors.toSet() );
+        for ( int i = 0; i < ITERATIONS; i++ )
+        {
+            TextValue textValue = randomValue.nextAlphaString( 5, 10 );
+            String asString = textValue.stringValue();
+            for ( int j = 0; j < asString.length(); j++ )
+            {
+                int ch = asString.charAt( j );
+                assertTrue( "Not a character " + ch,  Character.isAlphabetic( ch ));
+                seenDigits.remove( ch );
+            }
+        }
+        assertThat( seenDigits, empty() );
+    }
+
+
     private void checkDistribution( Supplier<Value> supplier )
     {
         Set<Value> values = new HashSet<>();