Since `ignoring_interference_by_writer` is on by default now, we don't
need to explicitly document it (unless someone wants to turn it off, but
that's unlikely).
[ci skip]
`allow_value` matcher is, of course, concerned with setting values on a
particular attribute on a particular record, and then checking that the
record is valid after doing so. That comes with a caveat: if the
attribute is overridden in such a way so that the same value going into
the attribute isn't the same value coming out of it, then `allow_value`
will balk -- it'll say, "I can't do that because that changes how I
work."
That's all well and good, but what the attribute intentionally changes
incoming values? ActiveRecord's typecasting behavior, for instance,
would trigger such an exception. What if the developer needs a way to
get around this? This is where `ignoring_interference_by_writer` comes
into play. You can tack it on to the end of the matcher, and you're free
to go on your way.
So, prior to this commit you could already apply it to `allow_value`,
but now in this commit it also works on any other matcher.
But, one little thing: sometimes using this qualifier isn't going to
work. Perhaps you or something else actually *is* overriding the
attribute to change incoming values in a specific way, and perhaps the
value that comes out makes the record fail validation, and there's
nothing you can do about it. So in this case, even if you're using
`ignoring_interference_by_writer`, we want to inform you about what the
attribute is doing -- what the input and output was. And so we do.
Modify descriptions and failure messages for all matchers by way of
allow_value and put small angle brackets around inspected values. This
is to visually distinguish an inspected value from the rest of the text,
and is especially noticeable for complex values such as an array that
contains an object, particularly if the inspected version of the value
wraps onto another line. It's a little easier to see:
When attempting to set :attr on Example to ‹[#<Child id:
nil>]›...
rather than:
When attempting to set :attr on Example to [#<Child id:
nil>]...
This is part of a collection of commits that aim to improve failure
messages across the board, in order to make matchers easier to debug
when something goes wrong.
* Make the description of the matcher more readable.
* Add boolean methods to check whether `allow_nil` or `allow_blank` have
been specified, to conform to the interface that ValidationMatcher
introduces.
* Fix or fill in tests involving failure messages and descriptions to
match these changes and recent changes to ValidationMatcher and
allow_value.
Elliot Winkler