3 files changed, 115 insertions, 0 deletions
diff --git a/spec/ruby/library/stringio/initialize_spec.rb b/spec/ruby/library/stringio/initialize_spec.rb
index 1e8096e3bb..c597e328d3 100644
--- a/spec/ruby/library/stringio/initialize_spec.rb
+++ b/spec/ruby/library/stringio/initialize_spec.rb
@@ -163,6 +163,91 @@ describe "StringIO#initialize when passed [Object]" do
   end
 end
 
+# NOTE: Synchronise with core/io/new_spec.rb (core/io/shared/new.rb)
+describe "StringIO#initialize when passed keyword arguments" do
+  it "sets the mode based on the passed :mode option" do
+    io = StringIO.new("example", "r")
+    io.closed_read?.should be_false
+    io.closed_write?.should be_true
+  end
+
+  it "accepts a mode argument set to nil with a valid :mode option" do
+    @io = StringIO.new('', nil, mode: "w")
+    @io.write("foo").should == 3
+  end
+
+  it "accepts a mode argument with a :mode option set to nil" do
+    @io = StringIO.new('', "w", mode: nil)
+    @io.write("foo").should == 3
+  end
+
+  it "sets binmode from :binmode option" do
+    @io = StringIO.new('', 'w', binmode: true)
+    @io.external_encoding.to_s.should == "ASCII-8BIT" # #binmode? isn't implemented in StringIO
+  end
+
+  it "does not set binmode from false :binmode" do
+    @io = StringIO.new('', 'w', binmode: false)
+    @io.external_encoding.to_s.should == "UTF-8" # #binmode? isn't implemented in StringIO
+  end
+end
+
+# NOTE: Synchronise with core/io/new_spec.rb (core/io/shared/new.rb)
+describe "StringIO#initialize when passed keyword arguments and error happens" do
+  it "raises an error if passed encodings two ways" do
+    -> {
+      @io = StringIO.new('', 'w:ISO-8859-1', encoding: 'ISO-8859-1')
+    }.should raise_error(ArgumentError)
+    -> {
+      @io = StringIO.new('', 'w:ISO-8859-1', external_encoding: 'ISO-8859-1')
+    }.should raise_error(ArgumentError)
+    -> {
+      @io = StringIO.new('', 'w:ISO-8859-1:UTF-8', internal_encoding: 'ISO-8859-1')
+    }.should raise_error(ArgumentError)
+  end
+
+  it "raises an error if passed matching binary/text mode two ways" do
+    -> {
+      @io = StringIO.new('', "wb", binmode: true)
+    }.should raise_error(ArgumentError)
+    -> {
+      @io = StringIO.new('', "wt", textmode: true)
+    }.should raise_error(ArgumentError)
+
+    -> {
+      @io = StringIO.new('', "wb", textmode: false)
+    }.should raise_error(ArgumentError)
+    -> {
+      @io = StringIO.new('', "wt", binmode: false)
+    }.should raise_error(ArgumentError)
+  end
+
+  it "raises an error if passed conflicting binary/text mode two ways" do
+    -> {
+      @io = StringIO.new('', "wb", binmode: false)
+    }.should raise_error(ArgumentError)
+    -> {
+      @io = StringIO.new('', "wt", textmode: false)
+    }.should raise_error(ArgumentError)
+
+    -> {
+      @io = StringIO.new('', "wb", textmode: true)
+    }.should raise_error(ArgumentError)
+    -> {
+      @io = StringIO.new('', "wt", binmode: true)
+    }.should raise_error(ArgumentError)
+  end
+
+  it "raises an error when trying to set both binmode and textmode" do
+    -> {
+      @io = StringIO.new('', "w", textmode: true, binmode: true)
+    }.should raise_error(ArgumentError)
+    -> {
+      @io = StringIO.new('', File::Constants::WRONLY, textmode: true, binmode: true)
+    }.should raise_error(ArgumentError)
+  end
+end
+
 describe "StringIO#initialize when passed no arguments" do
   before :each do
     @io = StringIO.allocate
diff --git a/spec/ruby/library/stringio/new_spec.rb b/spec/ruby/library/stringio/new_spec.rb
new file mode 100644
index 0000000000..e36d210caa
--- /dev/null
+++ b/spec/ruby/library/stringio/new_spec.rb
@@ -0,0 +1,8 @@
+require_relative '../../spec_helper'
+require 'stringio'
+
+describe "StringIO.new" do
+  it "warns when called with a block" do
+    -> { eval("StringIO.new {}") }.should complain(/StringIO::new\(\) does not take block; use StringIO::open\(\) instead/)
+  end
+end
+\ No newline at end of file
diff --git a/spec/ruby/library/stringio/shared/write.rb b/spec/ruby/library/stringio/shared/write.rb
index c5a0f8f513..d9c21028e0 100644
--- a/spec/ruby/library/stringio/shared/write.rb
+++ b/spec/ruby/library/stringio/shared/write.rb
@@ -66,6 +66,28 @@ describe :stringio_write_string, shared: true do
       @io.tainted?.should be_false
     end
   end
+
+  it "handles writing non-ASCII UTF-8 after seek" do
+    @io.binmode
+    @io << "\x80"
+    @io.pos = 0
+    @io << "\x81"
+    @io.string.should == "\x812345".b
+  end
+
+  it "handles writing with position < buffer size" do
+    @io.pos = 2
+    @io.write "abc"
+    @io.string.should == "12abc"
+
+    @io.pos = 2
+    @io.write "de"
+    @io.string.should == "12dec"
+
+    @io.pos = 2
+    @io.write "fghi"
+    @io.string.should == "12fghi"
+  end
 end
 
 describe :stringio_write_not_writable, shared: true do