ricardohsd/typecaster — pull request #3 by fellix (2012-10-10 02:11:19+00:00)
Title: Add a simple validation when defining some values inside the Typecaster ...

...object

Sometimes we make some typos when writing a new object
in greater objects is harder to find where it happens.
this validation checks with a friendly message instead the ugly

```
NoMethodError:
undefined method `[]=' for nil:NilClass
```

now it will raise something like that

```
attribute xpto is not defined
```