1 files changed, 76 insertions, 0 deletions
diff --git a/spec/ruby/core/io/write_nonblock_spec.rb b/spec/ruby/core/io/write_nonblock_spec.rb
new file mode 100644
index 0000000000..a6a263e931
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+++ b/spec/ruby/core/io/write_nonblock_spec.rb
@@ -0,0 +1,76 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+require File.expand_path('../shared/write', __FILE__)
+
+# See https://bugs.ruby-lang.org/issues/5954#note-5
+platform_is_not :windows do
+  describe "IO#write_nonblock on a file" do
+    before :each do
+      @filename = tmp("IO_syswrite_file") + $$.to_s
+      File.open(@filename, "w") do |file|
+        file.write_nonblock("012345678901234567890123456789")
+      end
+      @file = File.open(@filename, "r+")
+      @readonly_file = File.open(@filename)
+    end
+
+    after :each do
+      @file.close if @file
+      @readonly_file.close if @readonly_file
+      rm_r @filename
+    end
+
+    it "writes all of the string's bytes but does not buffer them" do
+      written = @file.write_nonblock("abcde")
+      written.should == 5
+      File.open(@filename) do |file|
+        file.sysread(10).should == "abcde56789"
+        file.seek(0)
+        @file.fsync
+        file.sysread(10).should == "abcde56789"
+      end
+    end
+
+    it "checks if the file is writable if writing zero bytes" do
+      lambda { @readonly_file.write_nonblock("") }.should raise_error
+    end
+  end
+
+  describe "IO#write_nonblock" do
+    it_behaves_like :io_write, :write_nonblock
+  end
+end
+
+describe 'IO#write_nonblock' do
+  before do
+    @read, @write = IO.pipe
+  end
+
+  after do
+    @read.close
+    @write.close
+  end
+
+  it "raises an exception extending IO::WaitWritable when the write would block" do
+    lambda {
+      loop { @write.write_nonblock('a' * 10_000) }
+    }.should raise_error(IO::WaitWritable) { |e|
+      platform_is_not :windows do
+        e.should be_kind_of(Errno::EAGAIN)
+      end
+      platform_is :windows do
+        e.should be_kind_of(Errno::EWOULDBLOCK)
+      end
+    }
+  end
+
+  ruby_version_is "2.3" do
+    context "when exception option is set to false" do
+      it "returns :wait_writable when the operation would block" do
+        loop { break if @write.write_nonblock("a" * 10_000, exception: false) == :wait_writable }
+        1.should == 1
+      end
+    end
+  end
+
+end