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Project: RSpec Core 2.4

Publisher: RSpec

explicit subject

Use subject() in the group scope to explicitly define the value that is
returned by the subject() method in the example scope.

Scenarios
  1. subject in top level group
  2. subject in a nested group
  3. access subject from before block
  4. invoke helper method from subject block
  5. subject block is invoked at most once per example
subject in top level group
Given
a file named "top_level_subject_spec.rb" with: 
describe Array, "with some elements" do
  subject { [1,2,3] }
  it "should have the prescribed elements" do
    subject.should == [1,2,3]
  end
end
When
I run "rspec top_level_subject_spec.rb"
Then
the examples should all pass
subject in a nested group
Given
a file named "nested_subject_spec.rb" with: 
describe Array do
  subject { [1,2,3] }
  describe "with some elements" do
    it "should have the prescribed elements" do
      subject.should == [1,2,3]
    end
  end
end
When
I run "rspec nested_subject_spec.rb"
Then
the examples should all pass
access subject from before block
Given
a file named "top_level_subject_spec.rb" with: 
describe Array, "with some elements" do
  subject { [] }
  before { subject.push(1,2,3) }
  it "should have the prescribed elements" do
    subject.should == [1,2,3]
  end
end
When
I run "rspec top_level_subject_spec.rb"
Then
the examples should all pass
invoke helper method from subject block
Given
a file named "helper_subject_spec.rb" with: 
describe Array do
  def prepared_array; [1,2,3] end
  subject { prepared_array }
  describe "with some elements" do
    it "should have the prescribed elements" do
      subject.should == [1,2,3]
    end
  end
end
When
I run "rspec helper_subject_spec.rb"
Then
the examples should all pass
subject block is invoked at most once per example
Given
a file named "nil_subject_spec.rb" with: 
describe Array do
  describe "#[]" do
    context "with index out of bounds" do
      before { Array.should_receive(:one_two_three).once.and_return([1,2,3]) }
      subject { Array.one_two_three[42] }
      it { should be_nil }
    end
  end
end
When
I run "rspec nil_subject_spec.rb"
Then
the examples should all pass

Last published about 6 years ago by dchelimsky.