Accepting method arguments about rspec-its

[d-Pixie]

Nice trick to accomplish this with the gem as is:

RSpec.describe Range do
  let(:range) { described_class.new( 1, 10 )}

  describe '#cover?' do
    subject { range.method(:cover?) }

    its([2]) { is_expected.to eq true }
    its([1..4]) { is_expected.to eq true }
  end
end

Unfortunately not my idea 🙂 All credit goes to https://zverok.github.io/blog/2017-11-01-rspec-method-call.html

[ArturT]

I like it. Many times I felt lack of that feature. Would be great to have it.

[BenMorganIO]

I'm +1 for #its carrying multiple arguments.

[michael-harrison]

+1 :)

[stp-che]

I would like to have the second #its argument as a description overriding rather than the argument for tested method.

I mean I want to write like this

Person = Struct.new(:name)

describe Person do
  subject { Person.new("Jack") }
  its(:name, 'should be taken from initialization argument') { should == "Jack" }
end

so that it would generate the following documentation output:

Person
  name
    should be taken from initialization argument

[vamereh]

@stp-che 👍

[ArturT]

I think multiple arguments feature for tested method is more needed. We can also add as a last argument of its the description but what if tested method takes multiple arguments.

[BenMorganIO]

We could use a hash as a parameter. There could be a methods key with an
array or a single object as an input. For a description override, we could
have a should key.

On Thursday, August 14, 2014, Artur [email protected] wrote:

I think multiple arguments feature for tested method is more needed. We
can also add as a last argument of its the description but what if tested
method takes multiple arguments.

—
Reply to this email directly or view it on GitHub
#19 (comment).

[stp-che]

A hash, indeed, could solve the problem.
I imagine something like this:

its(:method, with: [arg1, arg2], should: 'return a value'){ ... }

[ArturT]

@stp-che +1 It looks nice. :)

[dnagir]

Just FYI guys.

There's a gem that does just this: https://github.com/dnagir/its

Although it hasn't been updated for a whilte I regularly use it in all my projects and it seems to be solid.

But TBH I would really love it to be part of rspec-it.

[jeremyf]

👍 This looks very nice.

[palfvin]

My apologies for not responding to this or any other issues/PRs for the last several months. I'll try to be better going forward.

That said, I'm inclined not to support this on the grounds that:

• The its method has historically been in place to support "attributes", i.e. argument-less methods which can be thought of as returning some "property" of the object, rather than arbitrary methods which "do something". Introducing support for arbitrary methods seems like it's heading down a slippery support of incorporating more general support for expectations.
• I'd rather see additional arguments be used to provide support for other RSpec cababilities (e.g. metadata).

I see that others have supported this extension, but I'd like to hear from anyone who might be opposed.

[DArrigoni]

Personally, I probably would not use this and would end up ignoring it. I agree that "its" semantically feels appropriate for properties rather than method calls.

That said, a corollary that might work would be something like a 'call' or 'send' method, so it would look like...

call(:some_method, with: [an_arguement, another_argument]) { should pass_some_assertion }

Such a thing seems beyond the scope of this project however.

[pirj]

Another option that doesn't involve rspec-its:

describe '#root' do
  def root(x)
    MathExample.new.root(x)
  end

  it { expect(root(16)).to eq 4 }
  it { expect(root(9)).to eq 3 }
end

RSpec.describe Range do
  subject(:range) { described_class.new( 1, 10 )}

  describe '#cover?' do
    def cover?(range_or_value)
      range.cover?(range_or_value)
    end

    it { expect(cover?(2)).to be(true) }
    it { expect(cover?(1..4)).to be(true) }
  end
end

All credit goes to the Effective Testing with RSpec 3 book.