function hamming_distance(str1, str2)
   -- Your solution here
end

-- Tests -----------------------------------------------------------------------

package.path = package.path .. ";../luaunit/?.lua"
local luaunit = require("luaunit")

function test_distance_between_foo_and_bar_is_3()
   luaunit.assertEquals(hamming_distance("foo", "bar"), 3)
end

function test_distance_between_bar_and_baz_is_1()
   luaunit.assertEquals(hamming_distance("bar", "baz"), 1)
end

os.exit(luaunit.LuaUnit.run())