Handle query errors

lib/nocturne.rb

@@ -3,6 +3,7 @@
 require "socket"
 require "digest"
 require_relative "nocturne/error"
+require_relative "nocturne/protocol"
 require_relative "nocturne/protocol/connection"
 require_relative "nocturne/protocol/query"
 require_relative "nocturne/read/packet"

lib/nocturne/error.rb

@@ -6,4 +6,7 @@ class Error < StandardError
 
   class ConnectionError < Error
   end
+
+  class QueryError < Error
+  end
 end

lib/nocturne/protocol.rb

@@ -0,0 +1,14 @@
+#frozen_string_literal: true
+
+class Nocturne
+  module Protocol
+    def self.read_error(packet)
+      packet.int
+      code = packet.int(2)
+      packet.strn(1)
+      packet.strn(5)
+      message = packet.eof_str
+      [code, message]
+    end
+  end
+end

lib/nocturne/protocol/connection.rb

@@ -18,7 +18,7 @@ def establish
           if packet.ok?
             return
           elsif packet.err?
-            code, message = read_error(packet)
+            code, message = Protocol.read_error(packet)
             raise ConnectionError, "#{code}: #{message}"
           elsif packet.int == 0xFE # auth switch
             plugin = packet.nulstr
@@ -85,7 +85,7 @@ def auth_switch(plugin, data)
 
         @sock.read_packet do |packet|
           if packet.err?
-            code, message = read_error(packet)
+            code, message = Protocol.read_error(packet)
             raise ConnectionError, "#{code}: #{message}"
           end
         end
@@ -107,15 +107,6 @@ def mysql_native_password(scramble)
 
         bytes.pack("C*")
       end
-
-      def read_error(packet)
-        packet.int
-        code = packet.int(2)
-        packet.strn(1)
-        packet.strn(5)
-        message = packet.eof_str
-        [code, message]
-      end
     end
   end
 end

lib/nocturne/protocol/query.rb

@@ -20,6 +20,9 @@ def query(sql)
         @sock.read_packet do |payload|
           if payload.ok?
             # Done. No results.
+          elsif payload.err?
+            code, message = Protocol.read_error(payload)
+            raise QueryError, "#{code}: #{message}"
           else
             column_count = payload.lenenc_int
           end