1 files changed, 37 insertions, 0 deletions
diff --git a/spec/ruby/core/string/plus_spec.rb b/spec/ruby/core/string/plus_spec.rb
new file mode 100644
index 0000000000..9da17451c6
--- /dev/null
+++ b/spec/ruby/core/string/plus_spec.rb
@@ -0,0 +1,37 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+require_relative 'shared/concat'
+
+describe "String#+" do
+  it_behaves_like :string_concat_encoding, :+
+  it_behaves_like :string_concat_type_coercion, :+
+
+  it "returns a new string containing the given string concatenated to self" do
+    ("" + "").should == ""
+    ("" + "Hello").should == "Hello"
+    ("Hello" + "").should == "Hello"
+    ("Ruby !" + "= Rubinius").should == "Ruby != Rubinius"
+  end
+
+  it "converts any non-String argument with #to_str" do
+    c = mock 'str'
+    c.should_receive(:to_str).any_number_of_times.and_return(' + 1 = 2')
+
+    ("1" + c).should == '1 + 1 = 2'
+  end
+
+  it "raises a TypeError when given any object that fails #to_str" do
+    -> { "" + Object.new }.should raise_error(TypeError)
+    -> { "" + 65 }.should raise_error(TypeError)
+  end
+
+  it "doesn't return subclass instances" do
+    (StringSpecs::MyString.new("hello") + "").should be_an_instance_of(String)
+    (StringSpecs::MyString.new("hello") + "foo").should be_an_instance_of(String)
+    (StringSpecs::MyString.new("hello") + StringSpecs::MyString.new("foo")).should be_an_instance_of(String)
+    (StringSpecs::MyString.new("hello") + StringSpecs::MyString.new("")).should be_an_instance_of(String)
+    (StringSpecs::MyString.new("") + StringSpecs::MyString.new("")).should be_an_instance_of(String)
+    ("hello" + StringSpecs::MyString.new("foo")).should be_an_instance_of(String)
+    ("hello" + StringSpecs::MyString.new("")).should be_an_instance_of(String)
+  end
+end