Add index length option for MySQL

lib/SQL/Translator/Schema/Index.pm

@@ -221,7 +221,7 @@ around equals => sub {
     foreach my $otherField ($other->fields) {
       my $name = ref $otherField ? $otherField->{name} : $otherField;
       $name = uc($name) if $case_insensitive;
-      $otherFields{$name} = ref $otherField ? $otherField->{size} : -1; # -1 == no length. Easier comparison.
+      $otherFields{$name} = ref $otherField ? $otherField->{prefix_length} : -1; # -1 == no length. Easier comparison.
     }
     foreach my $selfField ($self->fields) { # check for self fields in hash
       my ($name, $size) = ref $selfField ? ($selfField->{name}, $selfField->{prefix_length}) : ($selfField, -1);

t/13schema.t

@@ -259,13 +259,13 @@ require_ok( 'SQL::Translator::Schema' );
 
     # Same indexes with different lengths
     my $index4 = SQL::Translator::Schema::Index->new(
-        name => "sized", fields => [ { name => 'forename', size => 20} ]
+        name => "sized", fields => [ { name => 'forename', prefix_length => 20} ]
     );
     ok( !$index3->equals($index4), "2 different indexes return false on equals() function (index length different)" );
 
     # Identical indexes with lengths
     my $index5 = SQL::Translator::Schema::Index->new(
-        name => "sized", fields => [ { name => 'forename', size => 15} ]
+        name => "sized", fields => [ { name => 'forename', prefix_length => 15} ]
     );
     ok( $index3->equals($index5), "2 identical indexes return true on equals() (with index length)" );