module RSpec::SubjectAsLambda
SubjectAsLambda
provides a convenient way of turning a regular subject into a proc
@author Mikael Henriksson <mikael@zoolutions.se>
Public Instance Methods
# File lib/rspec/subject_as_lambda.rb, line 116 def is_expected # rubocop:disable Lint/NestedMethodDefinition, Naming/PredicateName expect { __it_lambda_subject } end
Creates a nested example group named by the submitted `attribute`, and then generates an example using the submitted block.
@example
# This ... describe Array do its(:size) { should eq(0) } end # ... generates the same runtime structure as this: describe Array do describe "size" do it "should eq(0)" do subject.size.should eq(0) end end end
The attribute can be a `Symbol` or a `String`. Given a `String` with dots, the result is as though you concatenated that `String` onto the subject in an expression.
@example
describe Person do subject do Person.new.tap do |person| person.phone_numbers << "555-1212" end end its("phone_numbers.first") { should eq("555-1212") } end
When the subject is a `Hash`, you can refer to the Hash
keys by specifying a `Symbol` or `String` in an array.
@example
describe "a configuration Hash" do subject do { :max_users => 3, 'admin' => :all_permissions. 'john_doe' => {:permissions => [:read, :write]}} end its([:max_users]) { should eq(3) } its(['admin']) { should eq(:all_permissions) } its(['john_doe', :permissions]) { should eq([:read, :write]) } # You can still access its regular methods this way: its(:keys) { should include(:max_users) } its(:count) { should eq(2) } end
With an implicit subject, `is_expected` can be used as an alternative to `should` (e.g. for one-liner use). An `are_expected` alias is also supplied.
@example
describe Array do its(:size) { is_expected.to eq(0) } end
You can pass more than one argument on the `its` block to add some metadata to the generated example
@example
# This ... describe Array do its(:size, :focus) { should eq(0) } end # ... generates the same runtime structure as this: describe Array do describe "size" do it "should eq(0)", :focus do subject.size.should eq(0) end end end
Note that this method does not modify `subject` in any way, so if you refer to `subject` in `let` or `before` blocks, you're still referring to the outer subject.
@example
describe Person do subject { Person.new } before { subject.age = 25 } its(:age) { should eq(25) } end
# File lib/rspec/subject_as_lambda.rb, line 109 def it!(*options, &block) it_lambda_caller = caller.reject { |file_line| file_line =~ %r{/rspec/subject_as_lambda} } describe(nil, caller: it_lambda_caller) do let(:__it_lambda_subject) do subject end def is_expected # rubocop:disable Lint/NestedMethodDefinition, Naming/PredicateName expect { __it_lambda_subject } end alias_method :are_expected, :is_expected options << {} unless options.last.is_a?(Hash) options.last[:caller] = it_lambda_caller example(nil, *options, &block) end end