Module: RSpec::Core::Let::ClassMethods
- Defined in:
- lib/rspec/core/let.rb
Instance Method Summary collapse
-
#let(name, &block) ⇒ Object
Generates a method whose return value is memoized after the first call.
-
#let!(name, &block) ⇒ Object
Just like
let()
, except the block is invoked by an implicitbefore
hook.
Instance Method Details
#let(name, &block) ⇒ Object
Generates a method whose return value is memoized after the first call.
Examples
describe Thing do
let(:thing) { Thing.new }
it "does something" do
# first invocation, executes block, memoizes and returns result
thing.do_something
# second invocation, returns the memoized value
thing.should be_something
end
end
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# File 'lib/rspec/core/let.rb', line 22 def let(name, &block) define_method(name) do __memoized[name] ||= instance_eval(&block) end end |
#let!(name, &block) ⇒ Object
Just like let()
, except the block is invoked by an implicit before
hook. This serves a dual purpose of setting up state and providing a memoized reference to that state.
Examples
class Thing
def self.count
@count ||= 0
end
def self.count=(val)
@count += val
end
def self.reset_count
@count = 0
end
def initialize
self.class.count += 1
end
end
describe Thing do
after(:each) { Thing.reset_count }
context "using let" do
let(:thing) { Thing.new }
it "is not invoked implicitly" do
Thing.count.should == 0
end
it "can be invoked explicitly" do
thing
Thing.count.should == 1
end
end
context "using let!" do
let!(:thing) { Thing.new }
it "is invoked implicitly" do
Thing.count.should == 1
end
it "returns memoized version on first invocation" do
thing
Thing.count.should == 1
end
end
end
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# File 'lib/rspec/core/let.rb', line 82 def let!(name, &block) let(name, &block) before { __send__(name) } end |