1 files changed, 83 insertions, 20 deletions
diff --git a/spec/ruby/language/class_spec.rb b/spec/ruby/language/class_spec.rb
index d07454a3a7..6fb785fd56 100644
--- a/spec/ruby/language/class_spec.rb
+++ b/spec/ruby/language/class_spec.rb
@@ -17,6 +17,19 @@ describe "The class keyword" do
     eval "class ClassSpecsKeywordWithoutSemicolon end"
     ClassSpecsKeywordWithoutSemicolon.should be_an_instance_of(Class)
   end
+
+  it "can redefine a class when called from a block" do
+    ClassSpecs::DEFINE_CLASS.call
+    A.should be_an_instance_of(Class)
+
+    Object.send(:remove_const, :A)
+    defined?(A).should be_nil
+
+    ClassSpecs::DEFINE_CLASS.call
+    A.should be_an_instance_of(Class)
+  ensure
+    Object.send(:remove_const, :A) if defined?(::A)
+  end
 end
 
 describe "A class definition" do
@@ -30,27 +43,34 @@ describe "A class definition" do
   end
 
   it "raises TypeError if constant given as class name exists and is not a Module" do
-    lambda {
+    -> {
       class ClassSpecsNumber
       end
-    }.should raise_error(TypeError)
+    }.should raise_error(TypeError, /\AClassSpecsNumber is not a class/)
+  end
+
+  it "raises TypeError if constant given as class name exists and is a Module but not a Class" do
+    -> {
+      class ClassSpecs
+      end
+    }.should raise_error(TypeError, /\AClassSpecs is not a class/)
   end
 
   # test case known to be detecting bugs (JRuby, MRI)
   it "raises TypeError if the constant qualifying the class is nil" do
-    lambda {
+    -> {
       class nil::Foo
       end
     }.should raise_error(TypeError)
   end
 
   it "raises TypeError if any constant qualifying the class is not a Module" do
-    lambda {
+    -> {
       class ClassSpecs::Number::MyClass
       end
     }.should raise_error(TypeError)
 
-    lambda {
+    -> {
       class ClassSpecsNumber::MyClass
       end
     }.should raise_error(TypeError)
@@ -64,7 +84,7 @@ describe "A class definition" do
     module ClassSpecs
       class SuperclassResetToSubclass < L
       end
-      lambda {
+      -> {
         class SuperclassResetToSubclass < M
         end
       }.should raise_error(TypeError, /superclass mismatch/)
@@ -77,7 +97,7 @@ describe "A class definition" do
       end
       SuperclassReopenedBasicObject.superclass.should == A
 
-      lambda {
+      -> {
         class SuperclassReopenedBasicObject < BasicObject
         end
       }.should raise_error(TypeError, /superclass mismatch/)
@@ -92,7 +112,7 @@ describe "A class definition" do
       end
       SuperclassReopenedObject.superclass.should == A
 
-      lambda {
+      -> {
         class SuperclassReopenedObject < Object
         end
       }.should raise_error(TypeError, /superclass mismatch/)
@@ -117,7 +137,7 @@ describe "A class definition" do
       class NoSuperclassSet
       end
 
-      lambda {
+      -> {
         class NoSuperclassSet < String
         end
       }.should raise_error(TypeError, /superclass mismatch/)
@@ -127,7 +147,7 @@ describe "A class definition" do
   it "allows using self as the superclass if self is a class" do
     ClassSpecs::I::J.superclass.should == ClassSpecs::I
 
-    lambda {
+    -> {
       class ShouldNotWork < self; end
     }.should raise_error(TypeError)
   end
@@ -148,7 +168,7 @@ describe "A class definition" do
   it "raises a TypeError if inheriting from a metaclass" do
     obj = mock("metaclass super")
     meta = obj.singleton_class
-    lambda { class ClassSpecs::MetaclassSuper < meta; end }.should raise_error(TypeError)
+    -> { class ClassSpecs::MetaclassSuper < meta; end }.should raise_error(TypeError)
   end
 
   it "allows the declaration of class variables in the body" do
@@ -258,6 +278,8 @@ describe "A class definition" do
 
       AnonWithConstant.name.should == 'AnonWithConstant'
       klass.get_class_name.should == 'AnonWithConstant'
+    ensure
+      Object.send(:remove_const, :AnonWithConstant)
     end
   end
 end
@@ -274,7 +296,7 @@ describe "A class definition extending an object (sclass)" do
   end
 
   it "raises a TypeError when trying to extend numbers" do
-    lambda {
+    -> {
       eval <<-CODE
         class << 1
           def xyz
@@ -285,12 +307,20 @@ describe "A class definition extending an object (sclass)" do
     }.should raise_error(TypeError)
   end
 
-  ruby_version_is ""..."3.0" do
-    it "allows accessing the block of the original scope" do
-      suppress_warning do
-        ClassSpecs.sclass_with_block { 123 }.should == 123
-      end
-    end
+  it "raises a TypeError when trying to extend non-Class" do
+    error_msg = /superclass must be a.* Class/
+    -> { class TestClass < "";              end }.should raise_error(TypeError, error_msg)
+    -> { class TestClass < 1;               end }.should raise_error(TypeError, error_msg)
+    -> { class TestClass < :symbol;         end }.should raise_error(TypeError, error_msg)
+    -> { class TestClass < mock('o');       end }.should raise_error(TypeError, error_msg)
+    -> { class TestClass < Module.new;      end }.should raise_error(TypeError, error_msg)
+    -> { class TestClass < BasicObject.new; end }.should raise_error(TypeError, error_msg)
+  end
+
+  it "does not allow accessing the block of the original scope" do
+    -> {
+      ClassSpecs.sclass_with_block { 123 }
+    }.should raise_error(SyntaxError)
   end
 
   it "can use return to cause the enclosing method to return" do
@@ -310,11 +340,11 @@ describe "Reopening a class" do
   end
 
   it "raises a TypeError when superclasses mismatch" do
-    lambda { class ClassSpecs::A < Array; end }.should raise_error(TypeError)
+    -> { class ClassSpecs::A < Array; end }.should raise_error(TypeError)
   end
 
   it "adds new methods to subclasses" do
-    lambda { ClassSpecs::M.m }.should raise_error(NoMethodError)
+    -> { ClassSpecs::M.m }.should raise_error(NoMethodError)
     class ClassSpecs::L
       def self.m
         1
@@ -323,6 +353,39 @@ describe "Reopening a class" do
     ClassSpecs::M.m.should == 1
     ClassSpecs::L.singleton_class.send(:remove_method, :m)
   end
+
+  it "does not reopen a class included in Object" do
+    ruby_exe(<<~RUBY).should == "false"
+      module IncludedInObject
+        class IncludedClass
+        end
+      end
+      class Object
+        include IncludedInObject
+      end
+      class IncludedClass
+      end
+      print IncludedInObject::IncludedClass == Object::IncludedClass
+    RUBY
+  end
+
+  it "does not reopen a class included in non-Object modules" do
+    ruby_exe(<<~RUBY).should == "false/false"
+      module Included
+        module IncludedClass; end
+      end
+      module M
+        include Included
+        module IncludedClass; end
+      end
+      class C
+        include Included
+        module IncludedClass; end
+      end
+      print Included::IncludedClass == M::IncludedClass, "/",
+            Included::IncludedClass == C::IncludedClass
+    RUBY
+  end
 end
 
 describe "class provides hooks" do