1 files changed, 99 insertions, 0 deletions
diff --git a/spec/ruby/core/method/compose_spec.rb b/spec/ruby/core/method/compose_spec.rb
new file mode 100644
index 0000000000..7506e33ea8
--- /dev/null
+++ b/spec/ruby/core/method/compose_spec.rb
@@ -0,0 +1,99 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+require_relative '../proc/shared/compose'
+
+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
+      (pow_2 << double).should_not.lambda?
+    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).should.lambda?
+    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