1 files changed, 37 insertions, 13 deletions
diff --git a/spec/ruby/library/stringio/shared/read.rb b/spec/ruby/library/stringio/shared/read.rb
index 139c4fb02f..22f76b0fb0 100644
--- a/spec/ruby/library/stringio/shared/read.rb
+++ b/spec/ruby/library/stringio/shared/read.rb
@@ -5,30 +5,48 @@ describe :stringio_read, shared: true do
 
   it "returns the passed buffer String" do
     # Note: Rubinius bug:
-    # @io.send(@method, 7, buffer = "").should equal(buffer)
-    ret = @io.send(@method, 7, buffer = "")
+    # @io.send(@method, 7, buffer = +"").should equal(buffer)
+    ret = @io.send(@method, 7, buffer = +"")
     ret.should equal(buffer)
   end
 
   it "reads length bytes and writes them to the buffer String" do
-    @io.send(@method, 7, buffer = "")
+    @io.send(@method, 7, buffer = +"").should.equal?(buffer)
     buffer.should == "example"
   end
 
+  guard -> { StringIO::VERSION < "3.1.2" } do
+    it "does not preserve the encoding of the given buffer" do
+      buffer = ''.encode(Encoding::ISO_8859_1)
+      @io.send(@method, 7, buffer)
+
+      buffer.encoding.should_not == Encoding::ISO_8859_1
+    end
+  end
+
+  guard -> { StringIO::VERSION >= "3.1.2" } do
+    it "preserves the encoding of the given buffer" do
+      buffer = ''.encode(Encoding::ISO_8859_1)
+      @io.send(@method, 7, buffer)
+
+      buffer.encoding.should == Encoding::ISO_8859_1
+    end
+  end
+
   it "tries to convert the passed buffer Object to a String using #to_str" do
     obj = mock("to_str")
-    obj.should_receive(:to_str).and_return(buffer = "")
+    obj.should_receive(:to_str).and_return(buffer = +"")
 
     @io.send(@method, 7, obj)
     buffer.should == "example"
   end
 
   it "raises a TypeError when the passed buffer Object can't be converted to a String" do
-    lambda { @io.send(@method, 7, Object.new) }.should raise_error(TypeError)
+    -> { @io.send(@method, 7, Object.new) }.should raise_error(TypeError)
   end
 
-  it "raises a #{frozen_error_class} error when passed a frozen String as buffer" do
-    lambda { @io.send(@method, 7, "".freeze) }.should raise_error(frozen_error_class)
+  it "raises a FrozenError error when passed a frozen String as buffer" do
+    -> { @io.send(@method, 7, "".freeze) }.should raise_error(FrozenError)
   end
 end
 
@@ -61,11 +79,11 @@ describe :stringio_read_length, shared: true do
   end
 
   it "raises a TypeError when the passed length can't be converted to an Integer" do
-    lambda { @io.send(@method, Object.new) }.should raise_error(TypeError)
+    -> { @io.send(@method, Object.new) }.should raise_error(TypeError)
   end
 
   it "raises a TypeError when the passed length is negative" do
-    lambda { @io.send(@method, -2) }.should raise_error(ArgumentError)
+    -> { @io.send(@method, -2) }.should raise_error(ArgumentError)
   end
 
   it "returns a binary String" do
@@ -75,7 +93,7 @@ end
 
 describe :stringio_read_no_arguments, shared: true do
   before :each do
-    @io = StringIO.new("example")
+    @io = StringIO.new(+"example")
   end
 
   it "reads the whole content starting from the current position" do
@@ -89,6 +107,12 @@ describe :stringio_read_no_arguments, shared: true do
     @io.send(@method)
     @io.pos.should eql(7)
   end
+
+  it "correctly update the current position in bytes when multi-byte characters are used" do
+    @io.print("example\u03A3") # Overwrite the original string with 8 characters containing 9 bytes.
+    @io.send(@method)
+    @io.pos.should eql(9)
+  end
 end
 
 describe :stringio_read_nil, shared: true do
@@ -111,11 +135,11 @@ end
 
 describe :stringio_read_not_readable, shared: true do
   it "raises an IOError" do
-    io = StringIO.new("test", "w")
-    lambda { io.send(@method) }.should raise_error(IOError)
+    io = StringIO.new(+"test", "w")
+    -> { io.send(@method) }.should raise_error(IOError)
 
     io = StringIO.new("test")
     io.close_read
-    lambda { io.send(@method) }.should raise_error(IOError)
+    -> { io.send(@method) }.should raise_error(IOError)
   end
 end