ConfigurationBuilder.getDefaultXYZ returns internal instances

[per-erik]

Because ConfigurationBuilder.getDefaultXYZ returns the internal instances (and because of the way the documentation suggests to add stuff to the configuration builder), one can easily add for example matchers multiple times.

public int estimate(String password) {
    List<PasswordMatcher> matchers = ConfigurationBuilder.getDefaultPasswordMatchers();
            matchers.add(new PasswordMatcher() {
                @Override
                public List<Match> match(Configuration configuration, String password) {
                    System.out.println("Called with: " + password);
                    return new ArrayList<>();
                }
            });
    Configuration config = new ConfigurationBuilder()
        .setPasswordMatchers(matchers)
        .createConfiguration();
    Nbvcxz tester = new Nbvcxz(config)
    Result result = tester.estimate(password);
    return result.getBasicScore(); // Yes I've seen that you dislike this, but just to illustrate! :)
}

Running the above once will print "Called with ...". Running it a second time will print "Called with ..." twice, a third time trice, a fourth time will print it four times and so on.

One can get around this by either creating the configuration once (and not every time a test is made) or by wrapping the return value of ConfiguratioBuilder.getDefaultPasswordMatchers() in a new ArrayList.

This is not a big bug but given the documentation I spent a good half hour scratching my head as to why I was getting multiple calls to my "PasswordMatcher".

Best Regards,
Per-Erik

[Tostino]

Appreciate the bug report. Will look into it and get that fixed.

[ashleyfrieze]

I think the above may also result in a lack of thread safety. I was getting arraylist concurrent modification exceptions.

[Tostino]

Yeah, it absolutely would. I just got back from a two week vacation, so I have a bit to catch up on, but will try and get this sorted as quickly as I can. Pull requests are always welcome if someone gets to this before me.

[Tostino]

Took me a little bit, but have a fix in-progress: #82