1 files changed, 60 insertions, 0 deletions
diff --git a/spec/ruby/core/queue/initialize_spec.rb b/spec/ruby/core/queue/initialize_spec.rb
new file mode 100644
index 0000000000..592fbe2487
--- /dev/null
+++ b/spec/ruby/core/queue/initialize_spec.rb
@@ -0,0 +1,60 @@
+require_relative '../../spec_helper'
+
+describe "Queue#initialize" do
+  it "can be passed no arguments for an empty Queue" do
+    q = Queue.new
+    q.size.should == 0
+    q.should.empty?
+  end
+
+  it "is a private method" do
+    Queue.private_instance_methods.include?(:initialize).should == true
+  end
+
+  it "adds all elements of the passed Enumerable to self" do
+    q = Queue.new([1, 2, 3])
+    q.size.should == 3
+    q.should_not.empty?
+    q.pop.should == 1
+    q.pop.should == 2
+    q.pop.should == 3
+    q.should.empty?
+  end
+
+  describe "converts the given argument to an Array using #to_a" do
+    it "uses #to_a on the provided Enumerable" do
+      enumerable = MockObject.new('mock-enumerable')
+      enumerable.should_receive(:to_a).and_return([1, 2, 3])
+      q = Queue.new(enumerable)
+      q.size.should == 3
+      q.should_not.empty?
+      q.pop.should == 1
+      q.pop.should == 2
+      q.pop.should == 3
+      q.should.empty?
+    end
+
+    it "raises a TypeError if the given argument can't be converted to an Array" do
+      -> { Queue.new(42) }.should raise_error(TypeError)
+      -> { Queue.new(:abc) }.should raise_error(TypeError)
+    end
+
+    it "raises a NoMethodError if the given argument raises a NoMethodError during type coercion to an Array" do
+      enumerable = MockObject.new('mock-enumerable')
+      enumerable.should_receive(:to_a).and_raise(NoMethodError)
+      -> { Queue.new(enumerable) }.should raise_error(NoMethodError)
+    end
+  end
+
+  it "raises TypeError if the provided Enumerable does not respond to #to_a" do
+    enumerable = MockObject.new('mock-enumerable')
+    -> { Queue.new(enumerable) }.should raise_error(TypeError, "can't convert MockObject into Array")
+  end
+
+  it "raises TypeError if #to_a does not return Array" do
+    enumerable = MockObject.new('mock-enumerable')
+    enumerable.should_receive(:to_a).and_return("string")
+
+    -> { Queue.new(enumerable) }.should raise_error(TypeError, "can't convert MockObject to Array (MockObject#to_a gives String)")
+  end
+end