1 files changed, 104 insertions, 0 deletions
diff --git a/spec/ruby/core/enumerator/each_spec.rb b/spec/ruby/core/enumerator/each_spec.rb
new file mode 100644
index 0000000000..03be53fe05
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+++ b/spec/ruby/core/enumerator/each_spec.rb
@@ -0,0 +1,104 @@
+require_relative '../../spec_helper'
+
+describe "Enumerator#each" do
+  before :each do
+    object_each_with_arguments = Object.new
+    def object_each_with_arguments.each_with_arguments(arg, *args)
+      yield arg, *args
+      :method_returned
+    end
+
+    @enum_with_arguments = object_each_with_arguments.to_enum(:each_with_arguments, :arg0, :arg1, :arg2)
+
+    @enum_with_yielder = Enumerator.new { |y| y.yield :ok }
+  end
+
+  it "yields each element of self to the given block" do
+    acc = []
+    [1, 2, 3].to_enum.each { |e| acc << e }
+    acc.should == [1, 2, 3]
+  end
+
+  it "calls #each on the object given in the constructor by default" do
+    each = mock('each')
+    each.should_receive(:each)
+    each.to_enum.each { |e| e }
+  end
+
+  it "calls #each on the underlying object until it's exhausted" do
+    each = mock('each')
+    each.should_receive(:each).and_yield(1).and_yield(2).and_yield(3)
+    acc = []
+    each.to_enum.each { |e| acc << e }
+    acc.should == [1, 2, 3]
+  end
+
+  it "calls the method given in the constructor instead of #each" do
+    each = mock('peach')
+    each.should_receive(:peach)
+    each.to_enum(:peach).each { |e| e }
+  end
+
+  it "calls the method given in the constructor until it's exhausted" do
+    each = mock('peach')
+    each.should_receive(:peach).and_yield(1).and_yield(2).and_yield(3)
+    acc = []
+    each.to_enum(:peach).each { |e| acc << e }
+    acc.should == [1, 2, 3]
+  end
+
+  it "raises a NoMethodError if the object doesn't respond to #each" do
+    enum = Object.new.to_enum
+    -> do
+      enum.each { |e| e }
+    end.should.raise(NoMethodError)
+  end
+
+  it "returns self if not given arguments and not given a block" do
+    @enum_with_arguments.each.should.equal?(@enum_with_arguments)
+
+    @enum_with_yielder.each.should.equal?(@enum_with_yielder)
+  end
+
+  it "returns the same value from receiver.each if block is given" do
+    @enum_with_arguments.each {}.should.equal?(:method_returned)
+  end
+
+  it "passes given arguments at initialized to receiver.each" do
+    @enum_with_arguments.each.to_a.should == [[:arg0, :arg1, :arg2]]
+  end
+
+  it "requires multiple arguments" do
+    Enumerator.instance_method(:each).arity.should < 0
+  end
+
+  it "appends given arguments to receiver.each" do
+    @enum_with_arguments.each(:each0, :each1).to_a.should == [[:arg0, :arg1, :arg2, :each0, :each1]]
+    @enum_with_arguments.each(:each2, :each3).to_a.should == [[:arg0, :arg1, :arg2, :each2, :each3]]
+  end
+
+  it "returns the same value from receiver.each if block and arguments are given" do
+    @enum_with_arguments.each(:each1, :each2) {}.should.equal?(:method_returned)
+  end
+
+  it "returns new Enumerator if given arguments but not given a block" do
+    ret = @enum_with_arguments.each 1
+    ret.should.instance_of?(Enumerator)
+    ret.should_not.equal?(@enum_with_arguments)
+  end
+
+  it "does not destructure yielded array values when chaining each.map" do
+    result = [[[1]]].each.map { |a, b| [a, b] }
+    result.should == [[[1], nil]]
+  end
+
+  it "preserves array values yielded from the enumerator" do
+    result = [[1, 2]].each.map { |a| a }
+    result.should == [[1, 2]]
+  end
+
+  it "allows destructuring to occur in the block, not the enumerator" do
+    result = [[1, 2]].each.map { |a, b| a }
+    result.should == [1]
+  end
+end