Common RSpec matcher cheatsheet

matcher_reference_spec.rb

# Just a nice quick example reference of some common RSpec matchers
# References: 
#   https://www.relishapp.com/rspec/rspec-expectations/docs/built-in-matchers
#   http://rspec.rubyforge.org/rspec/1.1.9/classes/Spec/Matchers.html

describe "a simple RSpec matcher" do
    it "should do Object Identity comparison" do
        3.should be(3)
        this = Array.new([1,2,3])
        this.should be this
        this.should_not be [1,2,3]
    end
    it "should do Equality comparisons" do
        true.should be_true
        false.should be_false
        nil.should be_nil
        'this'.should_not be_nil
        [].should be_empty
        this = Array.new([1,2,3])
        this.should eq [1,2,3]
    end
    it "should do String matching comparisons" do
        actual='3'
        expected = '3'
        actual.should =~ /3/
        actual.should match(/3/)
    end
    it "should handle Array & Range inclusion" do
        [1].should include(1)
        (1..10).should cover(3)
    end
    it "should handle exceptions & throws" do
        expect { raise TypeError }.to raise_error
        expect { throw :done }.to throw_symbol 
    end
    it "should " do
        { :a => 1 }.should have_key(:a)
    end

    it "should do > comparisons" do
        actual = 3
        expected = 2
        actual.should be >  expected
        actual.should be >= expected
    end
    it "should do < comparisons & delta comparison" do
        actual = 3
        expected = 4
        delta = 1
        actual.should be <= expected
        actual.should be <  expected
        actual.should be_within(delta).of(expected)
    end
    it "should do Equality comparisons" do
        actual = 3
        expected = 3
        actual.should == expected     # passes if actual == expected
        actual.should eql(expected)   # passes if actual.eql?(expected)
        actual.should equal(expected)
    end
end