1 files changed, 114 insertions, 0 deletions
diff --git a/spec/ruby/language/class_variable_spec.rb b/spec/ruby/language/class_variable_spec.rb
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+++ b/spec/ruby/language/class_variable_spec.rb
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+require_relative '../spec_helper'
+require_relative '../fixtures/class_variables'
+
+describe "A class variable" do
+  after :each do
+    ClassVariablesSpec::ClassA.new.cvar_a = :cvar_a
+  end
+
+  it "can be accessed from a subclass" do
+    ClassVariablesSpec::ClassB.new.cvar_a.should == :cvar_a
+  end
+
+  it "is set in the superclass" do
+    a = ClassVariablesSpec::ClassA.new
+    b = ClassVariablesSpec::ClassB.new
+    b.cvar_a = :new_val
+
+    a.cvar_a.should == :new_val
+  end
+end
+
+describe "A class variable defined in a module" do
+  after :each do
+    ClassVariablesSpec::ClassC.cvar_m = :value
+    ClassVariablesSpec::ClassC.remove_class_variable(:@@cvar) if ClassVariablesSpec::ClassC.cvar_defined?
+  end
+
+  it "can be accessed from classes that extend the module" do
+    ClassVariablesSpec::ClassC.cvar_m.should == :value
+  end
+
+  it "is not defined in these classes" do
+    ClassVariablesSpec::ClassC.cvar_defined?.should be_false
+  end
+
+  it "is only updated in the module a method defined in the module is used" do
+    ClassVariablesSpec::ClassC.cvar_m = "new value"
+    ClassVariablesSpec::ClassC.cvar_m.should == "new value"
+
+    ClassVariablesSpec::ClassC.cvar_defined?.should be_false
+  end
+
+  it "is updated in the class when a Method defined in the class is used" do
+    ClassVariablesSpec::ClassC.cvar_c = "new value"
+    ClassVariablesSpec::ClassC.cvar_defined?.should be_true
+  end
+
+  it "can be accessed inside the class using the module methods" do
+    ClassVariablesSpec::ClassC.cvar_c = "new value"
+    ClassVariablesSpec::ClassC.cvar_m.should == :value
+  end
+
+  it "can be accessed from modules that extend the module" do
+    ClassVariablesSpec::ModuleO.cvar_n.should == :value
+  end
+
+  it "is defined in the extended module" do
+    ClassVariablesSpec::ModuleN.class_variable_defined?(:@@cvar_n).should be_true
+  end
+
+  it "is not defined in the extending module" do
+    ClassVariablesSpec::ModuleO.class_variable_defined?(:@@cvar_n).should be_false
+  end
+end
+
+describe 'A class variable definition' do
+  it "is created in a module if any of the parents do not define it" do
+    a = Class.new
+    b = Class.new(a)
+    c = Class.new(b)
+    b.class_variable_set(:@@cv, :value)
+
+    -> { a.class_variable_get(:@@cv) }.should raise_error(NameError)
+    b.class_variable_get(:@@cv).should == :value
+    c.class_variable_get(:@@cv).should == :value
+
+    # updates the same variable
+    c.class_variable_set(:@@cv, :next)
+
+    -> { a.class_variable_get(:@@cv) }.should raise_error(NameError)
+    b.class_variable_get(:@@cv).should == :next
+    c.class_variable_get(:@@cv).should == :next
+  end
+end
+
+describe 'Accessing a class variable' do
+  it "raises a RuntimeError when accessed from the toplevel scope (not in some module or class)" do
+    -> {
+      eval "@@cvar_toplevel1"
+    }.should raise_error(RuntimeError, 'class variable access from toplevel')
+    -> {
+      eval "@@cvar_toplevel2 = 2"
+    }.should raise_error(RuntimeError, 'class variable access from toplevel')
+  end
+
+  it "does not raise an error when checking if defined from the toplevel scope" do
+    -> {
+      eval "defined?(@@cvar_toplevel1)"
+    }.should_not raise_error
+  end
+
+  it "raises a RuntimeError when a class variable is overtaken in an ancestor class" do
+    parent = Class.new()
+    subclass = Class.new(parent)
+    subclass.class_variable_set(:@@cvar_overtaken, :subclass)
+    parent.class_variable_set(:@@cvar_overtaken, :parent)
+
+    -> {
+      subclass.class_variable_get(:@@cvar_overtaken)
+    }.should raise_error(RuntimeError, /class variable @@cvar_overtaken of .+ is overtaken by .+/)
+
+    parent.class_variable_get(:@@cvar_overtaken).should == :parent
+  end
+end