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ruby--ruby/spec/ruby/core/method/compose_spec.rb
Alan Wu 99c7b0b7ea
Decide lambdaness of (f << g) using g (#2729)
* Deciding lambdaness of (f << g) using g

* Use version guards for spec changes
2019-12-30 17:47:58 -05:00

102 lines
3.1 KiB
Ruby

require_relative '../../spec_helper'
require_relative 'fixtures/classes'
require_relative '../proc/shared/compose'
ruby_version_is "2.6" do
describe "Method#<<" do
it "returns a Proc that is the composition of self and the passed Proc" do
succ = MethodSpecs::Composition.new.method(:succ)
upcase = proc { |s| s.upcase }
(succ << upcase).call('Ruby').should == "RUBZ"
end
it "calls passed Proc with arguments and then calls self with result" do
pow_2_proc = proc { |x| x * x }
double_proc = proc { |x| x + x }
pow_2_method = MethodSpecs::Composition.new.method(:pow_2)
double_method = MethodSpecs::Composition.new.method(:double)
(pow_2_method << double_proc).call(2).should == 16
(double_method << pow_2_proc).call(2).should == 8
end
it "accepts any callable object" do
inc = MethodSpecs::Composition.new.method(:inc)
double = Object.new
def double.call(n); n * 2; end
(inc << double).call(3).should == 7
end
it_behaves_like :proc_compose, :<<, -> { MethodSpecs::Composition.new.method(:upcase) }
describe "composition" do
it "is a lambda" do
pow_2 = MethodSpecs::Composition.new.method(:pow_2)
double = proc { |x| x + x }
(pow_2 << double).is_a?(Proc).should == true
ruby_version_is(''...'2.8') { (pow_2 << double).lambda?.should == true }
ruby_version_is('2.8') { (pow_2 << double).lambda?.should == false }
end
it "may accept multiple arguments" do
inc = MethodSpecs::Composition.new.method(:inc)
mul = proc { |n, m| n * m }
(inc << mul).call(2, 3).should == 7
end
end
end
describe "Method#>>" do
it "returns a Proc that is the composition of self and the passed Proc" do
upcase = proc { |s| s.upcase }
succ = MethodSpecs::Composition.new.method(:succ)
(succ >> upcase).call('Ruby').should == "RUBZ"
end
it "calls passed Proc with arguments and then calls self with result" do
pow_2_proc = proc { |x| x * x }
double_proc = proc { |x| x + x }
pow_2_method = MethodSpecs::Composition.new.method(:pow_2)
double_method = MethodSpecs::Composition.new.method(:double)
(pow_2_method >> double_proc).call(2).should == 8
(double_method >> pow_2_proc).call(2).should == 16
end
it "accepts any callable object" do
inc = MethodSpecs::Composition.new.method(:inc)
double = Object.new
def double.call(n); n * 2; end
(inc >> double).call(3).should == 8
end
it_behaves_like :proc_compose, :>>, -> { MethodSpecs::Composition.new.method(:upcase) }
describe "composition" do
it "is a lambda" do
pow_2 = MethodSpecs::Composition.new.method(:pow_2)
double = proc { |x| x + x }
(pow_2 >> double).is_a?(Proc).should == true
(pow_2 >> double).lambda?.should == true
end
it "may accept multiple arguments" do
mul = MethodSpecs::Composition.new.method(:mul)
inc = proc { |n| n + 1 }
(mul >> inc).call(2, 3).should == 7
end
end
end
end