Do not add properties 'errors', 'isValid' and 'isAnyMessageShown' to grouped obj

[delixfe]

The group function surprised me a bit by adding the following properties to view model:

var vm = {};
var group = ko.validation.group(vm);
typeof vm.errors === 'function'; // true
typeof vm.isValid=== 'function'; // true
typeof vm.isAnyMessageShown=== 'function'; // true

I stumbled over that after trying to find out why some unit tests failed (the reason being these properties).

Therefore I have added a new option addResultToVM to group which configures if to set these properties.

I have set that configuration to false because I think we should follow the principle of least surprise. But that might break existing code.

[khakulov]

@crissdev What do you think about this pull request? Can you merge changes to master?

[crissdev]

Adding new configuration options is something I'm trying to avoid in order to keep the API simple. This means configuration options should be well justified before adding them.
The validatedObservable has been updated to allow grouping options to be passed in fd8f408 - so further extension to ko.validation.group is possible.
I can see how the properties published to the view model can cause some issues, but why would you use validatedObservable if you're not interested about the properties it adds?

[khakulov]

ko.validation.init();

var form = ko.validatedObservable({
    first_name: ko.observable('John').extend({required: true}),
    last_name: ko.observable('Doe').extend({required: true}),
    email: ko.observable('john.doe(at)example.com').extend({required: true, email: true}),
});

form.isValid(); // <-- OK
form().isValid(); // <-- WTF???
form.errors(); // <-- OK
form().errors(); // <-- WTF???

form.errors.showAllMessages(); // <-- OK
form().isAnyMessageShown(); // <-- WTF??? should be form.errors.isAnyMessageShown()

ko.toJS(form()); // <-- WTF??? contains errors because email is not valid

[khakulov]

@crissdev i did new pull request on actual master state #465

[crissdev]

@khakulov Thanks. I'll take a closer look and see how mergeable it is 👍

[crissdev]

Closed in favor of #465