test/io_test.rb in bindata-2.3.1 vs test/io_test.rb in bindata-2.3.2

@@ -140,9 +140,88 @@
     io.with_buffer(10) do
       io.seekbytes(-1)
       io.offset.must_equal(2)
     end
   end
+
+  it "greater than stream size consumes all bytes" do
+    io.with_buffer(30) do
+      io.readbytes(4).must_equal "abcd"
+    end
+    io.offset.must_equal(20)
+  end
+
+  it "restricts #num_bytes_remaining" do
+    io.with_buffer(10) do
+      io.readbytes(2)
+      io.num_bytes_remaining.must_equal 8
+    end
+  end
+
+  it "greater than stream size doesn't restrict #num_bytes_remaining" do
+    io.with_buffer(30) do
+      io.readbytes(2)
+      io.num_bytes_remaining.must_equal 18
+    end
+  end
+end
+
+module IOReadWithReadahead
+  def test_rolls_back_short_reads
+    io.readbytes(2).must_equal "ab"
+    io.with_readahead do
+      io.readbytes(4).must_equal "cdef"
+    end
+    io.offset.must_equal 2
+  end
+
+  def test_rolls_back_read_all_bytes
+    io.readbytes(3).must_equal "abc"
+    io.with_readahead do
+      io.read_all_bytes.must_equal "defghijklmnopqrst"
+    end
+    io.offset.must_equal 3
+  end
+
+  def test_inside_buffer_rolls_back_reads
+    io.with_buffer(10) do
+      io.with_readahead do
+        io.readbytes(4).must_equal "abcd"
+      end
+      io.offset.must_equal 0
+    end
+    io.offset.must_equal 10
+  end
+
+  def test_outside_buffer_rolls_back_reads
+    io.with_readahead do
+      io.with_buffer(10) do
+        io.readbytes(4).must_equal "abcd"
+      end
+      io.offset.must_equal 10
+    end
+    io.offset.must_equal 0
+  end
+end
+
+describe BinData::IO::Read, "#with_readahead" do
+  let(:stream) { StringIO.new "abcdefghijklmnopqrst" }
+  let(:io) { BinData::IO::Read.new(stream) }
+
+  include IOReadWithReadahead
+end
+
+describe BinData::IO::Read, "unseekable stream #with_readahead" do
+  let(:stream) {
+    io = StringIO.new "abcdefghijklmnopqrst"
+    def io.pos
+      raise Errno::EPIPE
+    end
+    io
+  }
+  let(:io) { BinData::IO::Read.new(stream) }
+
+  include IOReadWithReadahead
 end
 
 describe BinData::IO::Write, "writing to non seekable stream" do
   before do
     @rd, @wr = IO::pipe