1 files changed, 98 insertions, 0 deletions
diff --git a/spec/ruby/core/module/constants_spec.rb b/spec/ruby/core/module/constants_spec.rb
new file mode 100644
index 0000000000..f2f12761e3
--- /dev/null
+++ b/spec/ruby/core/module/constants_spec.rb
@@ -0,0 +1,98 @@
+require_relative '../../spec_helper'
+require_relative '../../fixtures/constants'
+require_relative 'fixtures/classes'
+
+describe "Module.constants" do
+  it "returns an array of the names of all toplevel constants" do
+    count = Module.constants.size
+    module ConstantSpecsAdded
+    end
+    Module.constants.size.should == count + 1
+    Object.send(:remove_const, :ConstantSpecsAdded)
+  end
+
+  it "returns an array of Symbol names" do
+    # This in NOT an exhaustive list
+    Module.constants.to_set.should >= Set[
+                                    :Array, :Class, :Comparable, :Dir,
+                                    :Enumerable, :ENV, :Exception, :FalseClass,
+                                    :File, :Float, :Hash, :Integer, :IO,
+                                    :Kernel, :Math, :Method, :Module, :NilClass,
+                                    :Numeric, :Object, :Range, :Regexp, :String,
+                                    :Symbol, :Thread, :Time, :TrueClass]
+  end
+
+  it "returns Module's constants when given a parameter" do
+    direct = Module.constants(false)
+    indirect = Module.constants(true)
+    module ConstantSpecsIncludedModule
+      MODULE_CONSTANTS_SPECS_INDIRECT = :foo
+    end
+
+    class Module
+      MODULE_CONSTANTS_SPECS_DIRECT = :bar
+      include ConstantSpecsIncludedModule
+    end
+    (Module.constants(false) - direct).should == [:MODULE_CONSTANTS_SPECS_DIRECT]
+    (Module.constants(true) - indirect).sort.should == [:MODULE_CONSTANTS_SPECS_DIRECT, :MODULE_CONSTANTS_SPECS_INDIRECT]
+
+    Module.send(:remove_const, :MODULE_CONSTANTS_SPECS_DIRECT)
+    ConstantSpecsIncludedModule.send(:remove_const, :MODULE_CONSTANTS_SPECS_INDIRECT)
+  end
+end
+
+describe "Module#constants" do
+  it "returns an array of Symbol names of all constants defined in the module and all included modules" do
+    ConstantSpecs::ContainerA.constants.sort.should == [
+      :CS_CONST10, :CS_CONST10_LINE, :CS_CONST23, :CS_CONST24, :CS_CONST5, :ChildA
+    ]
+  end
+
+  it "returns all constants including inherited when passed true" do
+    ConstantSpecs::ContainerA.constants(true).sort.should == [
+      :CS_CONST10, :CS_CONST10_LINE, :CS_CONST23, :CS_CONST24, :CS_CONST5, :ChildA
+    ]
+  end
+
+  it "returns all constants including inherited when passed some object" do
+    ConstantSpecs::ContainerA.constants(Object.new).sort.should == [
+      :CS_CONST10, :CS_CONST10_LINE, :CS_CONST23, :CS_CONST24, :CS_CONST5, :ChildA
+    ]
+  end
+
+  it "doesn't returns inherited constants when passed false" do
+    ConstantSpecs::ContainerA.constants(false).sort.should == [
+      :CS_CONST10, :CS_CONST10_LINE, :CS_CONST23, :CS_CONST5, :ChildA
+    ]
+  end
+
+  it "doesn't returns inherited constants when passed nil" do
+    ConstantSpecs::ContainerA.constants(nil).sort.should == [
+      :CS_CONST10, :CS_CONST10_LINE, :CS_CONST23, :CS_CONST5, :ChildA
+    ]
+  end
+
+  it "returns only public constants" do
+    ModuleSpecs::PrivConstModule.constants.should == [:PUBLIC_CONSTANT]
+  end
+
+  it "returns only constants starting with an uppercase letter" do
+    # e.g. fatal, IO::generic_readable and IO::generic_writable should not be returned by Module#constants
+    Object.constants.each { |c| c[0].should == c[0].upcase }
+    IO.constants.each { |c| c[0].should == c[0].upcase }
+  end
+end
+
+describe "Module#constants" do
+  before :each do
+    ConstantSpecs::ModuleM::CS_CONST251 = :const251
+  end
+
+  after :each do
+    ConstantSpecs::ModuleM.send(:remove_const, :CS_CONST251)
+  end
+
+  it "includes names of constants defined after a module is included" do
+    ConstantSpecs::ContainerA.constants.should.include?(:CS_CONST251)
+  end
+end