11 files changed, 61 insertions, 31 deletions
diff --git a/spec/ruby/library/bigdecimal/divmod_spec.rb b/spec/ruby/library/bigdecimal/divmod_spec.rb
index 22b66c2d48..3a18b150dd 100644
--- a/spec/ruby/library/bigdecimal/divmod_spec.rb
+++ b/spec/ruby/library/bigdecimal/divmod_spec.rb
@@ -38,9 +38,9 @@ describe "BigDecimal#mod_part_of_divmod" do
   it "raises ZeroDivisionError if other is zero" do
     bd5667 = BigDecimal("5667.19")
 
-    lambda { bd5667.send(@method, 0) }.should raise_error(ZeroDivisionError)
-    lambda { bd5667.send(@method, BigDecimal("0")) }.should raise_error(ZeroDivisionError)
-    lambda { @zero.send(@method, @zero) }.should raise_error(ZeroDivisionError)
+    lambda { bd5667.mod_part_of_divmod(0) }.should raise_error(ZeroDivisionError)
+    lambda { bd5667.mod_part_of_divmod(BigDecimal("0")) }.should raise_error(ZeroDivisionError)
+    lambda { @zero.mod_part_of_divmod(@zero) }.should raise_error(ZeroDivisionError)
   end
 end
 
diff --git a/spec/ruby/library/bigdecimal/to_s_spec.rb b/spec/ruby/library/bigdecimal/to_s_spec.rb
index acc2e943f0..75741c5050 100644
--- a/spec/ruby/library/bigdecimal/to_s_spec.rb
+++ b/spec/ruby/library/bigdecimal/to_s_spec.rb
@@ -15,8 +15,16 @@ describe "BigDecimal#to_s" do
     @bigneg.to_s.kind_of?(String).should == true
   end
 
-  it "the default format looks like 0.xxxxEnn" do
-    @bigdec.to_s.should =~ /^0\.[0-9]*E[0-9]*$/i
+  ruby_version_is ''...'2.4' do
+    it "the default format looks like 0.xxxxEnn" do
+      @bigdec.to_s.should =~ /^0\.[0-9]*E[0-9]*$/
+    end
+  end
+
+  ruby_version_is '2.4' do
+    it "the default format looks like 0.xxxxenn" do
+      @bigdec.to_s.should =~ /^0\.[0-9]*e[0-9]*$/
+    end
   end
 
   it "takes an optional argument" do
@@ -63,10 +71,12 @@ describe "BigDecimal#to_s" do
   end
 
   it "can use conventional floating point notation" do
-    @bigdec.to_s("F").should == @bigdec_str
-    @bigneg.to_s("F").should == @bigneg_str
-    str2 = "+123.45678901 23456789"
-    BigDecimal('123.45678901234567890').to_s('+8F').should == str2
+    %w[f F].each do |format_char|
+      @bigdec.to_s(format_char).should == @bigdec_str
+      @bigneg.to_s(format_char).should == @bigneg_str
+      str2 = "+123.45678901 23456789"
+      BigDecimal('123.45678901234567890').to_s("+8#{format_char}").should == str2
+    end
   end
 
 end
diff --git a/spec/ruby/library/datetime/add_spec.rb b/spec/ruby/library/datetime/add_spec.rb
new file mode 100644
index 0000000000..a6d98914bd
--- /dev/null
+++ b/spec/ruby/library/datetime/add_spec.rb
@@ -0,0 +1,9 @@
+require_relative '../../spec_helper'
+require 'date'
+
+describe "DateTime#+" do
+  it "is able to add sub-millisecond precision values" do
+    datetime = DateTime.new(2017)
+    (datetime + 0.00001).to_time.usec.should == 864000
+  end
+end
diff --git a/spec/ruby/library/datetime/subtract_spec.rb b/spec/ruby/library/datetime/subtract_spec.rb
new file mode 100644
index 0000000000..ed88533246
--- /dev/null
+++ b/spec/ruby/library/datetime/subtract_spec.rb
@@ -0,0 +1,9 @@
+require_relative '../../spec_helper'
+require 'date'
+
+describe "DateTime#-" do
+  it "is able to subtract sub-millisecond precision values" do
+    date = DateTime.new(2017)
+    ((date + 0.00001) - date).should == Rational(1, 100000)
+  end
+end
diff --git a/spec/ruby/library/socket/unixsocket/open_spec.rb b/spec/ruby/library/socket/unixsocket/open_spec.rb
index 6c4b7c5676..ad5048fedd 100644
--- a/spec/ruby/library/socket/unixsocket/open_spec.rb
+++ b/spec/ruby/library/socket/unixsocket/open_spec.rb
@@ -19,7 +19,7 @@ describe "UNIXSocket.open" do
     end
 
     it "opens a unix socket on the specified file and yields it to the block" do
-      UNIXSocket.send(@method, @path) do |client|
+      UNIXSocket.open(@path) do |client|
         client.addr[0].should == "AF_UNIX"
         client.closed?.should == false
       end
diff --git a/spec/ruby/library/stringio/getbyte_spec.rb b/spec/ruby/library/stringio/getbyte_spec.rb
index 99737614b9..3daa3d8e02 100644
--- a/spec/ruby/library/stringio/getbyte_spec.rb
+++ b/spec/ruby/library/stringio/getbyte_spec.rb
@@ -8,9 +8,9 @@ describe "StringIO#getbyte" do
   it "returns the 8-bit byte at the current position" do
     io = StringIO.new("example")
 
-    io.send(@method).should == 101
-    io.send(@method).should == 120
-    io.send(@method).should ==  97
+    io.getbyte.should == 101
+    io.getbyte.should == 120
+    io.getbyte.should ==  97
   end
 end
 
diff --git a/spec/ruby/library/stringio/getc_spec.rb b/spec/ruby/library/stringio/getc_spec.rb
index 9c0a28a1f0..263d418316 100644
--- a/spec/ruby/library/stringio/getc_spec.rb
+++ b/spec/ruby/library/stringio/getc_spec.rb
@@ -8,9 +8,9 @@ describe "StringIO#getc" do
   it "returns the character at the current position" do
     io = StringIO.new("example")
 
-    io.send(@method).should == ?e
-    io.send(@method).should == ?x
-    io.send(@method).should == ?a
+    io.getc.should == ?e
+    io.getc.should == ?x
+    io.getc.should == ?a
   end
 end
 
diff --git a/spec/ruby/library/stringio/getch_spec.rb b/spec/ruby/library/stringio/getch_spec.rb
index cd846705de..06670a178c 100644
--- a/spec/ruby/library/stringio/getch_spec.rb
+++ b/spec/ruby/library/stringio/getch_spec.rb
@@ -12,32 +12,32 @@ describe "StringIO#getch" do
   it "returns the character at the current position" do
     io = StringIO.new("example")
 
-    io.send(@method).should == ?e
-    io.send(@method).should == ?x
-    io.send(@method).should == ?a
+    io.getch.should == ?e
+    io.getch.should == ?x
+    io.getch.should == ?a
   end
 
   with_feature :encoding do
     it "increments #pos by the byte size of the character in multibyte strings" do
       io = StringIO.new("föóbar")
 
-      io.send(@method); io.pos.should == 1 # "f" has byte size 1
-      io.send(@method); io.pos.should == 3 # "ö" has byte size 2
-      io.send(@method); io.pos.should == 5 # "ó" has byte size 2
-      io.send(@method); io.pos.should == 6 # "b" has byte size 1
+      io.getch; io.pos.should == 1 # "f" has byte size 1
+      io.getch; io.pos.should == 3 # "ö" has byte size 2
+      io.getch; io.pos.should == 5 # "ó" has byte size 2
+      io.getch; io.pos.should == 6 # "b" has byte size 1
     end
   end
 
   it "returns nil at the end of the string" do
     # empty string case
     io = StringIO.new("")
-    io.send(@method).should == nil
-    io.send(@method).should == nil
+    io.getch.should == nil
+    io.getch.should == nil
 
     # non-empty string case
     io = StringIO.new("a")
-    io.send(@method) # skip one
-    io.send(@method).should == nil
+    io.getch # skip one
+    io.getch.should == nil
   end
 
   describe "StringIO#getch when self is not readable" do
diff --git a/spec/ruby/library/stringio/readbyte_spec.rb b/spec/ruby/library/stringio/readbyte_spec.rb
index b87b88b9c2..41a0911293 100644
--- a/spec/ruby/library/stringio/readbyte_spec.rb
+++ b/spec/ruby/library/stringio/readbyte_spec.rb
@@ -8,10 +8,10 @@ describe "StringIO#readbyte" do
   it "reads the next 8-bit byte from self's current position" do
     io = StringIO.new("example")
 
-    io.send(@method).should == 101
+    io.readbyte.should == 101
 
     io.pos = 4
-    io.send(@method).should == 112
+    io.readbyte.should == 112
   end
 end
 
diff --git a/spec/ruby/library/stringio/readchar_spec.rb b/spec/ruby/library/stringio/readchar_spec.rb
index 1d2ad45b9a..38944819a2 100644
--- a/spec/ruby/library/stringio/readchar_spec.rb
+++ b/spec/ruby/library/stringio/readchar_spec.rb
@@ -8,10 +8,10 @@ describe "StringIO#readchar" do
   it "reads the next 8-bit byte from self's current position" do
     io = StringIO.new("example")
 
-    io.send(@method).should == ?e
+    io.readchar.should == ?e
 
     io.pos = 4
-    io.send(@method).should == ?p
+    io.readchar.should == ?p
   end
 end
 
diff --git a/spec/ruby/library/zlib/crc32_spec.rb b/spec/ruby/library/zlib/crc32_spec.rb
index 5c39586ed9..02f95fd92c 100644
--- a/spec/ruby/library/zlib/crc32_spec.rb
+++ b/spec/ruby/library/zlib/crc32_spec.rb
@@ -24,6 +24,8 @@ describe "Zlib.crc32" do
     Zlib.crc32(test_string, 1).should == 1809313411
     Zlib.crc32(test_string, 2**8).should == 1722745982
     Zlib.crc32(test_string, 2**16).should == 1932511220
+    Zlib.crc32("p", ~305419896).should == 4046865307
+    Zlib.crc32("p", -305419897).should == 4046865307
     lambda { Zlib.crc32(test_string, 2**128) }.should raise_error(RangeError)
   end