Fixed formatting, improved test

Author: PetrPytelka

src/main/java/com/scriptbasic/utility/functions/StringFunctions.java

@@ -79,7 +79,7 @@ static public String cstr(final Object o) throws BasicRuntimeException {
     @BasicFunction(classification = {com.scriptbasic.classification.String.class,
             com.scriptbasic.classification.Utility.class})
     static public String ltrim(final Object o) throws BasicRuntimeException {
-        if(o==null) {
+        if (o == null) {
             return null;
         }
         final String s = cstr(o);

src/test/resources/com/scriptbasic/testprograms/TestStringFunctions.bas

@@ -10,9 +10,9 @@ assert("trim", trim(v)="1234")
 assert("rtrim", rtrim(v)=" 1234")
 
 ' Test null values
-assert("ltrim_with_null", IsNull(ltrim(xxx)))
-assert("trim_with_null", IsNull(trim(xxx)))
-assert("rtrim_with_null", IsNull(rtrim(xxx)))
+assert("ltrim_with_null", IsNull(ltrim(undefined_var)))
+assert("trim_with_null", IsNull(trim(undefined_var)))
+assert("rtrim_with_null", IsNull(rtrim(undefined_var)))
 
 ' Test left, mid, right functions
 v = 1234