Add let! and subject! to RSpec adapter

- Implement let! for eagerly-evaluated memoized helpers
- Implement subject! for eagerly-evaluated subjects
- Support inheritance of eager lets from parent describe blocks
- Reorganize tests into folders (one describe per file)

Author: joeldrapper

lib/quickdraw/rspec/spec.rb

@@ -32,10 +32,15 @@ def it(description, &)
 		end
 
 		def subject(name = nil, &)
-			let("subject", &)
+			let(:subject, &)
 			let(name, &) if name
 		end
 
+		def subject!(name = nil, &)
+			let!(:subject, &)
+			let!(name, &) if name
+		end
+
 		def let(name, &block)
 			instance_variable = :"@#{name}"
 
@@ -47,12 +52,31 @@ def let(name, &block)
 				end
 			end
 		end
+
+		def let!(name, &)
+			let(name, &)
+			own_eager_lets << name
+		end
+
+		def eager_lets
+			parent = superclass.respond_to?(:eager_lets) ? superclass.eager_lets : []
+			parent + own_eager_lets
+		end
+
+		def own_eager_lets
+			@eager_lets ||= []
+		end
 	end
 
 	def described_class
 		self.class.described_class
 	end
 
+	def setup
+		super
+		self.class.eager_lets.each { |name| send(name) }
+	end
+
 	def expect(subject)
 		Quickdraw::RSpec::Expectation.new(subject, context: self)
 	end

test/rspec/let/let.test.rb

@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+require "quickdraw/rspec"
+
+Quickdraw::RSpec.describe "let" do
+	let(:value) { "hello" }
+
+	it "provides the value" do
+		expect(value).to eq("hello")
+	end
+
+	it "memoizes the value" do
+		expect(value).to equal(value)
+	end
+
+	describe "with a counter" do
+		let(:counter) { @count ||= 0; @count += 1 }
+
+		it "is lazy - not evaluated until called" do
+			# counter not called yet, so @count should be nil
+			expect(@count).to be_nil
+			expect(counter).to eq(1)
+		end
+
+		it "memoizes across multiple calls in same test" do
+			expect(counter).to eq(1)
+			expect(counter).to eq(1)
+			expect(counter).to eq(1)
+		end
+	end
+
+	describe "inheritance" do
+		let(:inherited) { "parent" }
+
+		describe "nested" do
+			it "inherits let from parent" do
+				expect(inherited).to eq("parent")
+			end
+		end
+
+		describe "override" do
+			let(:inherited) { "child" }
+
+			it "can override parent let" do
+				expect(inherited).to eq("child")
+			end
+		end
+	end
+
+	describe "referencing other lets" do
+		let(:first) { "hello" }
+		let(:second) { "#{first} world" }
+
+		it "can reference other let values" do
+			expect(second).to eq("hello world")
+		end
+	end
+end

test/rspec/let/let_bang.test.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require "quickdraw/rspec"
+
+Quickdraw::RSpec.describe "let!" do
+	let!(:eager_value) { @evaluated = true; "eager" }
+
+	it "is evaluated before the test runs" do
+		expect(@evaluated).to eq(true)
+	end
+
+	it "provides the value" do
+		expect(eager_value).to eq("eager")
+	end
+
+	it "memoizes the value" do
+		expect(eager_value).to equal(eager_value)
+	end
+
+	describe "inheritance" do
+		let!(:parent_eager) { @parent_evaluated = true; "parent" }
+
+		describe "nested" do
+			it "inherits let! from parent and evaluates it" do
+				expect(@parent_evaluated).to eq(true)
+				expect(parent_eager).to eq("parent")
+			end
+		end
+	end
+end

test/rspec/subject/subject.test.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+require "quickdraw/rspec"
+
+Quickdraw::RSpec.describe "subject" do
+	subject { "the subject" }
+
+	it "provides the subject" do
+		expect(subject).to eq("the subject")
+	end
+
+	it "memoizes the subject" do
+		expect(subject).to equal(subject)
+	end
+
+	describe "named subject" do
+		subject(:my_string) { "named" }
+
+		it "provides subject" do
+			expect(subject).to eq("named")
+		end
+
+		it "provides named accessor" do
+			expect(my_string).to eq("named")
+		end
+
+		it "named accessor equals subject" do
+			expect(my_string).to equal(subject)
+		end
+	end
+
+	describe "inheritance" do
+		subject { "parent subject" }
+
+		describe "nested" do
+			it "inherits subject from parent" do
+				expect(subject).to eq("parent subject")
+			end
+		end
+
+		describe "override" do
+			subject { "child subject" }
+
+			it "can override parent subject" do
+				expect(subject).to eq("child subject")
+			end
+		end
+	end
+end

test/rspec/subject/subject_bang.test.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require "quickdraw/rspec"
+
+Quickdraw::RSpec.describe "subject!" do
+	subject! { @evaluated = true; "eager subject" }
+
+	it "is evaluated before the test runs" do
+		expect(@evaluated).to eq(true)
+	end
+
+	it "provides the subject" do
+		expect(subject).to eq("eager subject")
+	end
+
+	describe "named subject!" do
+		subject!(:my_eager) { @named_evaluated = true; "named eager" }
+
+		it "is evaluated before the test runs" do
+			expect(@named_evaluated).to eq(true)
+		end
+
+		it "provides subject" do
+			expect(subject).to eq("named eager")
+		end
+
+		it "provides named accessor" do
+			expect(my_eager).to eq("named eager")
+		end
+	end
+end