1 files changed, 148 insertions, 0 deletions
diff --git a/spec/ruby/core/io/read_nonblock_spec.rb b/spec/ruby/core/io/read_nonblock_spec.rb
new file mode 100644
index 0000000000..511cf03263
--- /dev/null
+++ b/spec/ruby/core/io/read_nonblock_spec.rb
@@ -0,0 +1,148 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "IO#read_nonblock" do
+  before :each do
+    @read, @write = IO.pipe
+  end
+
+  after :each do
+    @read.close if @read && !@read.closed?
+    @write.close if @write && !@write.closed?
+  end
+
+  it "raises an exception extending IO::WaitReadable when there is no data" do
+    -> { @read.read_nonblock(5) }.should.raise(IO::WaitReadable) { |e|
+      platform_is_not :windows do
+        e.should.is_a?(Errno::EAGAIN)
+      end
+      platform_is :windows do
+        e.should.is_a?(Errno::EWOULDBLOCK)
+      end
+    }
+  end
+
+  context "when exception option is set to false" do
+    context "when there is no data" do
+      it "returns :wait_readable" do
+        @read.read_nonblock(5, exception: false).should == :wait_readable
+      end
+    end
+
+    context "when the end is reached" do
+      it "returns nil" do
+        @write << "hello"
+        @write.close
+
+        @read.read_nonblock(5)
+
+        @read.read_nonblock(5, exception: false).should == nil
+      end
+    end
+  end
+
+  platform_is_not :windows do
+    it 'sets the IO in nonblock mode' do
+      require 'io/nonblock'
+      @write.write "abc"
+      @read.read_nonblock(1).should == "a"
+      @read.should.nonblock?
+    end
+  end
+
+  it "returns at most the number of bytes requested" do
+    @write << "hello"
+    @read.read_nonblock(4).should == "hell"
+  end
+
+  it "reads after ungetc with data in the buffer" do
+    @write.write("foobar")
+    @read.set_encoding(
+      'utf-8', universal_newline: false
+    )
+    c = @read.getc
+    @read.ungetc(c)
+    @read.read_nonblock(3).should == "foo"
+    @read.read_nonblock(3).should == "bar"
+  end
+
+  it "raises an exception after ungetc with data in the buffer and character conversion enabled" do
+    @write.write("foobar")
+    @read.set_encoding(
+      'utf-8', universal_newline: true
+    )
+    c = @read.getc
+    @read.ungetc(c)
+    -> { @read.read_nonblock(3).should == "foo" }.should.raise(IOError)
+  end
+
+  it "returns less data if that is all that is available" do
+    @write << "hello"
+    @read.read_nonblock(10).should == "hello"
+  end
+
+  it "allows for reading 0 bytes before any write" do
+    @read.read_nonblock(0).should == ""
+  end
+
+  it "allows for reading 0 bytes after a write" do
+    @write.write "1"
+    @read.read_nonblock(0).should == ""
+    @read.read_nonblock(1).should == "1"
+  end
+
+  it "raises ArgumentError when length is less than 0" do
+    -> { @read.read_nonblock(-1) }.should.raise(ArgumentError)
+  end
+
+  it "reads into the passed buffer" do
+    buffer = +""
+    @write.write("1")
+    @read.read_nonblock(1, buffer)
+    buffer.should == "1"
+  end
+
+  it "returns the passed buffer" do
+    buffer = +""
+    @write.write("1")
+    output = @read.read_nonblock(1, buffer)
+    output.should.equal?(buffer)
+  end
+
+  it "discards the existing buffer content upon successful read" do
+    buffer = +"existing content"
+    @write.write("hello world")
+    @write.close
+    @read.read_nonblock(11, buffer)
+    buffer.should == "hello world"
+  end
+
+  it "discards the existing buffer content upon error" do
+    buffer = +"existing content"
+    @write.close
+    -> { @read.read_nonblock(1, buffer) }.should.raise(EOFError)
+    buffer.should.empty?
+  end
+
+  it "raises IOError on closed stream" do
+    -> { IOSpecs.closed_io.read_nonblock(5) }.should.raise(IOError)
+  end
+
+  it "raises EOFError when the end is reached" do
+    @write << "hello"
+    @write.close
+
+    @read.read_nonblock(5)
+
+    -> { @read.read_nonblock(5) }.should.raise(EOFError)
+  end
+
+  it "preserves the encoding of the given buffer" do
+    buffer = ''.encode(Encoding::ISO_8859_1)
+    @write.write("abc")
+    @write.close
+    @read.read_nonblock(10, buffer)
+
+    buffer.encoding.should == Encoding::ISO_8859_1
+  end
+end