Add geodist command

Author: TheSmartnik

lib/redis.rb

@@ -2755,6 +2755,18 @@ def geopos(key, member)
     end
   end
 
+  # Returns the distance between two members of a geospatial index
+  #
+  # @param [String ]key
+  # @param [Array<String>] members
+  # @param ['m', 'km', 'mi', 'ft'] unit
+  # @return [String, nil] returns distance in spefied unit if both members present, nil otherwise.
+  def geodist(key, member1, member2, unit = 'm')
+    synchronize do |client|
+      client.call([:geodist, key, member1, member2, unit])
+    end
+  end
+
   # Interact with the sentinel command (masters, master, slaves, failover)
   #
   # @param [String] subcommand e.g. `masters`, `master`, `slaves`

test/commands_on_geo_test.rb

@@ -59,4 +59,17 @@ def test_geopos_nonexistant_location
     locations = r.geopos("Sicily", ["Rome", "Catania"])
     assert_equal [nil, ["15.08726745843887329", "37.50266842333162032"]], locations
   end
+
+  def test_geodist
+    distination_in_meters = r.geodist("Sicily", "Palermo", "Catania")
+    assert_equal "166274.1516", distination_in_meters
+
+    distination_in_feet = r.geodist("Sicily", "Palermo", "Catania", 'ft')
+    assert_equal "545518.8700", distination_in_feet
+  end
+
+  def test_geodist_with_nonexistant_location
+    distination = r.geodist("Sicily", "Palermo", "Rome")
+    assert_equal nil, distination
+  end
 end