Fix BufferedIO to search with byteindex

As of #184,
the buffer String is no longer BINARY but UTF-8.

I missed that the code that search for newlines was using `.index`
instead of `.byteindex`, causing the buffer offset to go out of
sync.

Author: byroot

.rubocop.yml

@@ -208,3 +208,6 @@ Style/CaseLikeIf:
 
 Style/EmptyMethod:
   Enabled: false
+
+Style/AccessModifierDeclarations:
+  Enabled: false

lib/redis_client/ruby_connection/buffered_io.rb

@@ -10,14 +10,80 @@ class BufferedIO
 
       attr_accessor :read_timeout, :write_timeout
 
-      def initialize(io, read_timeout:, write_timeout:, chunk_size: 4096)
-        @io = io
-        @buffer = +""
-        @offset = 0
-        @chunk_size = chunk_size
-        @read_timeout = read_timeout
-        @write_timeout = write_timeout
-        @blocking_reads = false
+      if String.method_defined?(:byteindex) # Ruby 3.2+
+        ENCODING = Encoding::UTF_8
+
+        def initialize(io, read_timeout:, write_timeout:, chunk_size: 4096)
+          @io = io
+          @buffer = +""
+          @offset = 0
+          @chunk_size = chunk_size
+          @read_timeout = read_timeout
+          @write_timeout = write_timeout
+          @blocking_reads = false
+        end
+
+        def gets_chomp
+          fill_buffer(false) if @offset >= @buffer.bytesize
+          until eol_index = @buffer.byteindex(EOL, @offset)
+            fill_buffer(false)
+          end
+
+          line = @buffer.byteslice(@offset, eol_index - @offset)
+          @offset = eol_index + EOL_SIZE
+          line
+        end
+
+        def read_chomp(bytes)
+          ensure_remaining(bytes + EOL_SIZE)
+          str = @buffer.byteslice(@offset, bytes)
+          @offset += bytes + EOL_SIZE
+          str
+        end
+
+        private def ensure_line
+          fill_buffer(false) if @offset >= @buffer.bytesize
+          until @buffer.byteindex(EOL, @offset)
+            fill_buffer(false)
+          end
+        end
+      else
+        ENCODING = Encoding::BINARY
+
+        def initialize(io, read_timeout:, write_timeout:, chunk_size: 4096)
+          @io = io
+          @buffer = "".b
+          @offset = 0
+          @chunk_size = chunk_size
+          @read_timeout = read_timeout
+          @write_timeout = write_timeout
+          @blocking_reads = false
+        end
+
+        def gets_chomp
+          fill_buffer(false) if @offset >= @buffer.bytesize
+          until eol_index = @buffer.index(EOL, @offset)
+            fill_buffer(false)
+          end
+
+          line = @buffer.byteslice(@offset, eol_index - @offset)
+          @offset = eol_index + EOL_SIZE
+          line
+        end
+
+        def read_chomp(bytes)
+          ensure_remaining(bytes + EOL_SIZE)
+          str = @buffer.byteslice(@offset, bytes)
+          @offset += bytes + EOL_SIZE
+          str.force_encoding(Encoding::UTF_8)
+        end
+
+        private def ensure_line
+          fill_buffer(false) if @offset >= @buffer.bytesize
+          until @buffer.index(EOL, @offset)
+            fill_buffer(false)
+          end
+        end
       end
 
       def close
@@ -90,17 +156,6 @@ def getbyte
         byte
       end
 
-      def gets_chomp
-        fill_buffer(false) if @offset >= @buffer.bytesize
-        until eol_index = @buffer.index(EOL, @offset)
-          fill_buffer(false)
-        end
-
-        line = @buffer.byteslice(@offset, eol_index - @offset)
-        @offset = eol_index + EOL_SIZE
-        line
-      end
-
       def gets_integer
         int = 0
         offset = @offset
@@ -124,22 +179,8 @@ def gets_integer
         int
       end
 
-      def read_chomp(bytes)
-        ensure_remaining(bytes + EOL_SIZE)
-        str = @buffer.byteslice(@offset, bytes)
-        @offset += bytes + EOL_SIZE
-        str
-      end
-
       private
 
-      def ensure_line
-        fill_buffer(false) if @offset >= @buffer.bytesize
-        until @buffer.index(EOL, @offset)
-          fill_buffer(false)
-        end
-      end
-
       def ensure_remaining(bytes)
         needed = bytes - (@buffer.bytesize - @offset)
         if needed > 0
@@ -171,9 +212,9 @@ def fill_buffer(strict, size = @chunk_size)
             if empty_buffer
               @offset = start
               empty_buffer = false
-              @buffer.force_encoding(Encoding::UTF_8) unless @buffer.encoding == Encoding::UTF_8
+              @buffer.force_encoding(ENCODING) unless @buffer.encoding == ENCODING
             else
-              @buffer << bytes.force_encoding(Encoding::UTF_8)
+              @buffer << bytes.force_encoding(ENCODING)
             end
             remaining -= bytes.bytesize
             return if !strict || remaining <= 0

test/redis_client/resp3_test.rb

@@ -108,6 +108,11 @@ def test_load_array
       assert_parses [1, 2, 3], "*3\r\n:1\r\n:2\r\n:3\r\n"
     end
 
+    def test_load_multibyte_chars
+      # Check that the buffer is properly operating over bytes and not characters
+      assert_parses ["۪۪", 2], "*2\r\n$12\r\n۪۪\r\n:2\r\n"
+    end
+
     def test_load_set
       assert_parses ['orange', 'apple', true, 100, 999], "~5\r\n+orange\r\n+apple\r\n#t\r\n:100\r\n:999\r\n"
     end