9 files changed, 56 insertions, 13 deletions
diff --git a/spec/ruby/library/bigdecimal/BigDecimal_spec.rb b/spec/ruby/library/bigdecimal/BigDecimal_spec.rb
index 52f026fb2b..03f0c0adfd 100644
--- a/spec/ruby/library/bigdecimal/BigDecimal_spec.rb
+++ b/spec/ruby/library/bigdecimal/BigDecimal_spec.rb
@@ -1,6 +1,12 @@
 require_relative '../../spec_helper'
 require 'bigdecimal'
 
+describe "BigDecimal" do
+  it "is not defined unless it is required" do
+    ruby_exe('puts Object.const_defined?(:BigDecimal)').should == "false\n"
+  end
+end
+
 describe "Kernel#BigDecimal" do
 
   it "creates a new object of class BigDecimal" do
diff --git a/spec/ruby/library/bigdecimal/minus_spec.rb b/spec/ruby/library/bigdecimal/minus_spec.rb
index 02f7f02296..267a0f7eab 100644
--- a/spec/ruby/library/bigdecimal/minus_spec.rb
+++ b/spec/ruby/library/bigdecimal/minus_spec.rb
@@ -55,4 +55,12 @@ describe "BigDecimal#-" do
     (@one_minus - @infinity).should == @infinity_minus
   end
 
+  describe "with Object" do
+    it "tries to coerce the other operand to self" do
+      object = mock("Object")
+      object.should_receive(:coerce).with(@one).and_return([@one, BigDecimal("42")])
+      (@one - object).should == BigDecimal("-41")
+    end
+  end
+
 end
diff --git a/spec/ruby/library/bigdecimal/plus_spec.rb b/spec/ruby/library/bigdecimal/plus_spec.rb
index 9247ff6146..cefc43aeaa 100644
--- a/spec/ruby/library/bigdecimal/plus_spec.rb
+++ b/spec/ruby/library/bigdecimal/plus_spec.rb
@@ -44,4 +44,11 @@ describe "BigDecimal#+" do
     (@infinity + @infinity_minus).nan?.should == true
   end
 
+  describe "with Object" do
+    it "tries to coerce the other operand to self" do
+      object = mock("Object")
+      object.should_receive(:coerce).with(@one).and_return([@one, BigDecimal("42")])
+      (@one + object).should == BigDecimal("43")
+    end
+  end
 end
diff --git a/spec/ruby/library/ipaddr/operator_spec.rb b/spec/ruby/library/ipaddr/operator_spec.rb
index fe94a39ae1..a0984bfcfe 100644
--- a/spec/ruby/library/ipaddr/operator_spec.rb
+++ b/spec/ruby/library/ipaddr/operator_spec.rb
@@ -2,14 +2,11 @@ require_relative '../../spec_helper'
 require 'ipaddr'
 
 describe "IPAddr Operator" do
-  IN6MASK32  = "ffff:ffff::"
-  IN6MASK128 = "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff"
-
   before do
     @in6_addr_any = IPAddr.new()
     @a = IPAddr.new("3ffe:505:2::/48")
     @b = IPAddr.new("0:0:0:1::")
-    @c = IPAddr.new(IN6MASK32)
+    @c = IPAddr.new("ffff:ffff::")
   end
 
   it "bitwises or" do
@@ -48,7 +45,7 @@ describe "IPAddr Operator" do
 
   it "inverts" do
     a = ~@in6_addr_any
-    a.to_s.should == IN6MASK128
+    a.to_s.should == "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff"
     @in6_addr_any.to_s.should == "::"
   end
 
diff --git a/spec/ruby/library/mathn/mathn_spec.rb b/spec/ruby/library/mathn/mathn_spec.rb
index c9e8c05a8d..129c8f3288 100644
--- a/spec/ruby/library/mathn/mathn_spec.rb
+++ b/spec/ruby/library/mathn/mathn_spec.rb
@@ -3,7 +3,11 @@ require_relative '../../spec_helper'
 describe "mathn" do
   ruby_version_is "2.5" do
     it "is no longer part of the standard library" do
-      -> { require "mathn" }.should raise_error(LoadError)
+      -> {
+        require "mathn"
+      }.should raise_error(LoadError) { |e|
+        e.path.should == 'mathn'
+      }
     end
   end
 end
diff --git a/spec/ruby/library/rbconfig/rbconfig_spec.rb b/spec/ruby/library/rbconfig/rbconfig_spec.rb
index caa557c32c..af74043c9c 100644
--- a/spec/ruby/library/rbconfig/rbconfig_spec.rb
+++ b/spec/ruby/library/rbconfig/rbconfig_spec.rb
@@ -1,11 +1,23 @@
 require_relative '../../spec_helper'
 require 'rbconfig'
 
-describe 'RbConfig::CONFIG values' do
-  it 'are all strings' do
+describe 'RbConfig::CONFIG' do
+  it 'values are all strings' do
     RbConfig::CONFIG.each do |k, v|
       k.should be_kind_of String
       v.should be_kind_of String
     end
   end
+
+  it "['rubylibdir'] returns the directory containing Ruby standard libraries" do
+    rubylibdir = RbConfig::CONFIG['rubylibdir']
+    File.directory?(rubylibdir).should == true
+    File.exist?("#{rubylibdir}/fileutils.rb").should == true
+  end
+
+  it "['archdir'] returns the directory containing standard libraries C extensions" do
+    archdir = RbConfig::CONFIG['archdir']
+    File.directory?(archdir).should == true
+    File.exist?("#{archdir}/etc.#{RbConfig::CONFIG['DLEXT']}").should == true
+  end
 end
diff --git a/spec/ruby/library/stringio/puts_spec.rb b/spec/ruby/library/stringio/puts_spec.rb
index 396d9f25f4..152bfb13f8 100644
--- a/spec/ruby/library/stringio/puts_spec.rb
+++ b/spec/ruby/library/stringio/puts_spec.rb
@@ -51,6 +51,14 @@ describe "StringIO#puts when passed an Array" do
     @io.puts([obj])
     @io.string.should == "to_s\n"
   end
+
+  it "returns general object info if :to_s does not return a string" do
+    object = mock('hola')
+    object.should_receive(:to_s).and_return(false)
+
+    @io.puts(object).should == nil
+    @io.string.should == object.inspect.split(" ")[0] + ">\n"
+  end
 end
 
 describe "StringIO#puts when passed 1 or more objects" do
diff --git a/spec/ruby/library/yaml/fixtures/example_class.rb b/spec/ruby/library/yaml/fixtures/example_class.rb
index 751435a305..8259870799 100644
--- a/spec/ruby/library/yaml/fixtures/example_class.rb
+++ b/spec/ruby/library/yaml/fixtures/example_class.rb
@@ -1,5 +1,7 @@
-class FooBar
-  def initialize(name)
-    @name = name
+module YAMLSpecs
+  class Example
+    def initialize(name)
+      @name = name
+    end
   end
 end
diff --git a/spec/ruby/library/yaml/to_yaml_spec.rb b/spec/ruby/library/yaml/to_yaml_spec.rb
index 9713657a26..d73ae9bee4 100644
--- a/spec/ruby/library/yaml/to_yaml_spec.rb
+++ b/spec/ruby/library/yaml/to_yaml_spec.rb
@@ -13,8 +13,7 @@ describe "Object#to_yaml" do
   end
 
   it "returns the YAML representation of a Class object" do
-    FooBar.new("baz").to_yaml.should match_yaml("--- !ruby/object:FooBar\nname: baz\n")
-
+    YAMLSpecs::Example.new("baz").to_yaml.should match_yaml("--- !ruby/object:YAMLSpecs::Example\nname: baz\n")
   end
 
   it "returns the YAML representation of a Date object" do