Use #public_send to disallow hitting private methods

[jamesottaway]

Fixes #28.

If the subject looks like this:

class Person < Struct.new(:name)
  private
  def inner_name
    "Inner #{name}"
  end
end

then its shouldn't be able to hit the inner_name method. The following test:

describe Person do
  subject { Person.new('John') }
  describe '#inner_name' do
    its(:inner_name} { is_expected.to eq 'Inner John' }
  end
end

should raise a NoMethodError.

[jamesottaway]

I finally remembered to come back to this and fix the broken build.

The easiest solution seemed to be to not run the broken spec on MRI 1.8.7

[jamesottaway]

@palfvin any idea when this could be merged?

There's also the conversation over in #28 about whether to drop support for 1.8.7 and bump the major version number.

[jamesottaway]

Bump.

[magni-]

Bump... maybe this could be part of a 1.3.0 release ? Had something break in production recently because we were unaware that its could call private methods 😞

[JonRowe]

This would require a 2.0.0 release as it's a breaking change, we could do this if theres enough interest however.

[JonRowe]

Whats that they say about better late than never? Theres been a few bugfixes recently so I'm launching a very minimal 2.0.0 and well as promised, this is included. Thank you.

[jamesottaway]

I love that this finally landed Jon, seriously thank you, but I'll admit that I'm a little sad I didn't get to celebrate this PR's 10th birthday. I had the date marked in my calendar, and it was only a month-and-a-bit away 😭