added #empty? to MySql2::Result

lib/mysql2/result.rb

@@ -2,6 +2,10 @@ module Mysql2
   class Result
     attr_reader :server_flags
 
+    def empty?
+      count.zero?
+    end
+
     include Enumerable
   end
 end

spec/mysql2/result_spec.rb

@@ -45,6 +45,7 @@
     r = @client.query "SELECT 1"
     expect(r.count).to eql(1)
     expect(r.size).to eql(1)
+    expect(r.empty?).to eq(false)
   end
 
   context "metadata queries" do
@@ -53,6 +54,18 @@
     end
   end
 
+  context "#empty?" do
+    it "should return true when result is not exists" do
+      r = @client.query "SELECT * FROM mysql2_test WHERE 0 = 1"
+      expect(r).to be_empty
+    end
+
+    it "should return false when result exists" do
+      r = @client.query "SELECT 1"
+      expect(r).not_to be_empty
+    end
+  end
+
   context "#each" do
     it "should yield rows as hash's" do
       @result.each do |row|