RSpec Demonstration is Missing Three Very Useful Things

[Marko A.]

I was pretty shocked that RSpec demonstration only scratched the surface.

RSpec is to me far superior to C# tests that come out of visual studio by default  because of these 3 things:

1) RSpec has ability to format tests as documentation and print it as such.

This is snipped example of such output (for specifications table class Specs in module Specs)

To get documentation for a file_spec.rb you'd type

rspec --format documentation file_spec.rb

or short -f d

rspec -f d file_spec.rb

This is output

Specs::ConvertableProperty

  behaves like a validated property

    .type_valid?

      returns true for all known types

      returns false for unknown type

    #allowed_units

      returns array when allowed_units for that type is an array

        for type :weight returns ["lbs", "kg"]

        for type :torque returns ["ft-lb", "Nm"]

    #unit_valid?

      when allowed units are given as array

        for type :weight

          returns true for

            "lbs"

            "kg"

          returns false for

            unit not listed in allowed_units[:weight]

            :weight unit is "lb" (missing last letter)

            :weight unit is "LBS" (wrong case)

            :weight unit is "k" (missing last letter)

            :weight unit is "KG" (wrong case)

        for type :torque

          returns true for

            "ft-lb"

            "Nm"

          returns false for

            unit not listed in allowed_units[:torque]

            :torque unit is "ft-l" (missing last letter)

            :torque unit is "FT-LB" (wrong case)

            :torque unit is "N" (missing last letter)

            :torque unit is "nM" (wrong case)

...

When you are reading tests for code you didn't write it's much better to start with an overview like this and read into test code if you want to.

2) Specs (tests) can be created dynamically

3) Specs (tests) can be reused

Here is example that explains both. I have added comments for non ruby programmers # this is a comment

For non ruby - rspec users:

 describe or context is a nested block of tests

 it is a test

    shared_examples_for 'close looking strings' do |unit, type|

      subject { tested_class.new(type) }

      missing_letter_unit = unit[0..-2]

      it "#{type.inspect} unit is #{missing_letter_unit.inspect} \

(missing last letter)" do

        expect(subject.unit_valid?(missing_letter_unit)).to be false

      end

      if wrong_case = unit.dup.swapcase!

        it "#{type.inspect} unit is #{wrong_case.inspect} (wrong case)" do

          expect(subject.unit_valid?(wrong_case)).to be false

        end

      end

    end

This is generating test cases for missing last letter and wrong case. I am using them like this:

          context 'returns false for' do

             # irrelevant code snipped

             units.each do |unit|

              include_examples 'close looking strings', unit, type

            end

          end

Result is that test cases for missing last letter and wrong case are auto generated for each type

This is documentation output for the relevant part.

        for type :weight

          returns true for

            "lbs"

            "kg"

          returns false for

            unit not listed in allowed_units[:weight]

            :weight unit is "lb" (missing last letter)

            :weight unit is "LBS" (wrong case)

            :weight unit is "k" (missing last letter)

            :weight unit is "KG" (wrong case)

Is everything clear or do I need to explain something further?

I think C# / Java test tools don't have any of these features. Am I correct?