1 files changed, 83 insertions, 0 deletions
diff --git a/spec/ruby/core/module/attr_writer_spec.rb b/spec/ruby/core/module/attr_writer_spec.rb
new file mode 100644
index 0000000000..6089b52495
--- /dev/null
+++ b/spec/ruby/core/module/attr_writer_spec.rb
@@ -0,0 +1,83 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+require_relative 'shared/attr_added'
+
+describe "Module#attr_writer" do
+  it "creates a setter for each given attribute name" do
+    c = Class.new do
+      attr_writer :test1, "test2"
+    end
+    o = c.new
+
+    o.respond_to?("test1").should == false
+    o.respond_to?("test2").should == false
+
+    o.respond_to?("test1=").should == true
+    o.test1 = "test_1"
+    o.instance_variable_get(:@test1).should == "test_1"
+
+    o.respond_to?("test2=").should == true
+    o.test2 = "test_2"
+    o.instance_variable_get(:@test2).should == "test_2"
+    o.send(:test1=,"test_1 updated")
+    o.instance_variable_get(:@test1).should == "test_1 updated"
+    o.send(:test2=,"test_2 updated")
+    o.instance_variable_get(:@test2).should == "test_2 updated"
+  end
+
+  it "not allows for adding an attr_writer to an immediate" do
+    class TrueClass
+      attr_writer :spec_attr_writer
+    end
+
+    -> { true.spec_attr_writer = "a" }.should.raise(FrozenError)
+  end
+
+  it "raises FrozenError if the receiver if frozen" do
+    c = Class.new do
+      attr_writer :foo
+    end
+    obj = c.new
+    obj.freeze
+
+    -> { obj.foo = 42 }.should.raise(FrozenError)
+  end
+
+  it "converts non string/symbol names to strings using to_str" do
+    (o = mock('test')).should_receive(:to_str).any_number_of_times.and_return("test")
+    c = Class.new do
+      attr_writer o
+    end
+
+    c.new.respond_to?("test").should == false
+    c.new.respond_to?("test=").should == true
+  end
+
+  it "raises a TypeError when the given names can't be converted to strings using to_str" do
+    o = mock('test1')
+    -> { Class.new { attr_writer o } }.should.raise(TypeError)
+    (o = mock('123')).should_receive(:to_str).and_return(123)
+    -> { Class.new { attr_writer o } }.should.raise(TypeError)
+  end
+
+  it "applies current visibility to methods created" do
+    c = Class.new do
+      protected
+      attr_writer :foo
+    end
+
+    -> { c.new.foo=1 }.should.raise(NoMethodError)
+  end
+
+  it "is a public method" do
+    Module.public_instance_methods(false).should.include?(:attr_writer)
+  end
+
+  it "returns an array of defined method names as symbols" do
+    Class.new do
+      (attr_writer :foo, 'bar').should == [:foo=, :bar=]
+    end
+  end
+
+  it_behaves_like :module_attr_added, :attr_writer
+end