diff --git a/spec/cbor_spec.cr b/spec/cbor_spec.cr
index 4d6dc79..66bfa87 100644
--- a/spec/cbor_spec.cr
+++ b/spec/cbor_spec.cr
@@ -1,5 +1,96 @@
 require "./spec_helper"
 
-describe CBOR do
-  # TODO: Write tests
+class Location
+  include CBOR::Serializable
+
+  @[CBOR::Field(key: "lat")]
+  property latitude : Float64
+
+  @[CBOR::Field(key: "lng")]
+  property longitude : Float64
+
+  def initialize(@latitude, @longitude)
+  end
+end
+
+class House
+  include CBOR::Serializable
+
+  property address   : String
+  property location  : Location?
+
+  def initialize(@address)
+  end
+end
+
+class Person
+	include CBOR::Serializable
+	include CBOR::Serializable::Unmapped
+
+	property name : String?
+	def initialize(@name = nil)
+	end
+end
+
+describe CBOR do
+
+  describe "basics: to_cbor" do
+    it "array - strings" do
+      ["a", "b", "c"].to_cbor.hexstring.should eq "83616161626163"
+    end
+    it "array - " do
+      ["a", "b", "c"].to_cbor.hexstring.should eq "83616161626163"
+    end
+    it "hash" do
+      {"a" => 10, "b" => true, "c" => nil}.to_cbor.hexstring.should eq "a361610a6162f56163f6"
+    end
+  end
+
+  describe "CBOR library annotations and features" do
+    it "Person#from_cbor with unmapped values" do
+      h = Hash(String | Int32, String | Int32).new
+      h["name"] = "Alice"
+      h["age"]  = 30
+      h["size"] = 160
+      alice = Person.from_cbor h.to_cbor
+      alice.to_cbor.hexstring.should eq "a3646e616d6565416c69636563616765181e6473697a6518a0"
+    end
+
+    it "Person#to_cbor with unmapped values" do
+      alice = Person.new "Alice"
+      alice.cbor_unmapped["age"] = 30
+      alice.cbor_unmapped["size"] = 160
+      alice.to_cbor.hexstring.should eq "a3646e616d6565416c69636563616765181e6473697a6518a0"
+    end
+  end
+
+  describe "CBOR::Any" do
+    it "from JSON::Any - 1" do
+      h_any = {"a" => "b", "c" => "d", "e" => true, "f" => 10}
+      json_any = JSON.parse h_any.to_json
+      cbor_any = CBOR::Any.new json_any
+      cbor_any.to_cbor.hexstring.should eq "a461616162616361646165f561660a"
+    end
+
+    it "from JSON::Any - 2" do
+      h_any = {"a" => "b", "c" => "d", "e" => true, "f" => 10}
+      json_any = JSON.parse h_any.to_json
+      cbor_any = CBOR::Any.new json_any
+      cbor_any["f"].should eq 10
+    end
+
+    it "from array" do
+      array = CBOR::Any.from_cbor [ "a", "b", "c", "d" ].to_cbor
+      array.to_cbor.hexstring.should eq "846161616261636164"
+    end
+
+    it "from hash" do
+      h_cany = Hash(String | Int32, String | Int32).new
+      h_cany["name"] = "Alice"
+      h_cany["age"]  = 30
+      h_cany["size"] = 160
+      cbor_any_hash = CBOR::Any.from_cbor h_cany.to_cbor
+      cbor_any_hash.to_cbor.hexstring.should eq "a3646e616d6565416c69636563616765181e6473697a6518a0"
+    end
+  end
 end