Merge pull request ipaddress-gem#21 from Adam21e/find_adjacent

Find adjacent

.byebug_history

@@ -0,0 +1,25 @@
+c
+[split.map{|i| i.to_string} - [current_subnet]][0]
+c
+[current_subnet]
+split - [current_subnet]
+split[0] == current_subnet
+current_subnet
+split - [current_subnet]
+current_subnet
+split
+prefix
+prfix
+c
+self.prefix
+prefix
+self
+@prefix
+prefix
+continue
+c
+@prefix.host_prefix
+@prefix
+current_subnet
+n
+current_subnet

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## [Unreleased]
 
+### Enhancements
+* Added 'find\_adjacent_subnet' to IPv6
+
 ## 0.10.0
 
 ### Enhancements

lib/ipaddress/ipv4.rb

@@ -1151,6 +1151,22 @@ def allocate(skip=0)
         self.class.parse_u32(network_u32+@allocator, @prefix)
     end
 
+    #
+    # Finds the adjacent block to a subnet.
+    #
+    # Example:
+    #
+    #    ip = IPAddress("10.0.0.0/24")
+    #    ip.find_adjacent_subnet
+    #      #=> "10.0.1.0/24"
+    #
+    def find_adjacent_subnet
+      return false if prefix == 0
+      current_subnet = to_string
+      self.prefix = @prefix - 1
+      (split.map{|i| i.to_string} - [current_subnet])[0]
+    end
+
     #
     # private methods
     #

lib/ipaddress/ipv6.rb

@@ -964,6 +964,22 @@ def allocate(skip=0)
         self.class.parse_u128(next_ip, @prefix)
     end
 
+    #
+    # Finds the adjacent block to a subnet.
+    #
+    # Example:
+    #
+    #    ip = IPAddress("2001:db8::/32")
+    #    ip.find_adjacent_subnet
+    #      #=> "2001:db9::/32"
+    #
+    def find_adjacent_subnet
+      return false if prefix == 0
+      current_subnet = to_string
+      self.prefix = @prefix - 1
+      (split.map{|i| i.to_string} - [current_subnet])[0]
+    end
+
     private
 
     def newprefix(num)

test/ipaddress/ipv4_test.rb

@@ -686,6 +686,16 @@ def test_allocate_will_raise_stopiteration
     end
   end
 
-end # class IPv4Test
+  def test_finds_adjacent_subnet
+    ip = @klass.new("10.0.0.0/24")
+    assert_equal "10.0.1.0/24", ip.find_adjacent_subnet
+    refute @klass.new("10.0.0.0/0").find_adjacent_subnet 
+    assert_equal "10.0.0.0/8", @klass.new("11.0.0.0/8").find_adjacent_subnet 
+    assert_equal "172.16.0.0/16", @klass.new("172.17.0.0/16").find_adjacent_subnet 
+    assert_equal "192.168.4.0/24", @klass.new("192.168.5.0/24").find_adjacent_subnet 
+    assert_equal "192.168.100.4/30", @klass.new("192.168.100.0/30").find_adjacent_subnet 
+    assert_equal "192.168.1.2/31", @klass.new("192.168.1.0/31").find_adjacent_subnet 
+    assert_equal "192.168.2.5/32", @klass.new("192.168.2.4/32").find_adjacent_subnet 
+  end
 
-  
+end # class IPv4Test

test/ipaddress/ipv6_test.rb

@@ -570,6 +570,15 @@ def test_group_updates
     assert_equal "2001:db8:4d2:0:8:800:200c:417a/64", ip.to_string
   end
 
+  def test_finds_adjacent_subnet
+    refute @klass.new("::/0").find_adjacent_subnet 
+    assert_equal "2001:db9::/32", @klass.new("2001:db8::/32").find_adjacent_subnet 
+    assert_equal "2001:db8:0:1::/64", @klass.new("2001:db8::/64").find_adjacent_subnet 
+    assert_equal "2001:db8:8:2000::/51", @klass.new("2001:db8:8::/51").find_adjacent_subnet 
+    # assert_equal "", @klass.new("").find_adjacent_subnet 
+    # assert_equal "", @klass.new("").find_adjacent_subnet 
+  end
+
 end # class IPv6Test
 
 class IPv6UnspecifiedTest < Minitest::Test