diff --git a/test/similarity/cosine_test.exs b/test/similarity/cosine_test.exs
index 5496bbf..cdefe29 100644
--- a/test/similarity/cosine_test.exs
+++ b/test/similarity/cosine_test.exs
@@ -49,4 +49,32 @@ defmodule Similarity.CosineTest do
 
     assert Cosine.between(s, "barna", "somebody") |> Float.round(3) == 0.585
   end
+
+  test "new" do
+    assert %Cosine{attributes_counter: 0, attributes_map: %{}, map: %{}} = Cosine.new()
+  end
+
+  test "add with empty attributes" do
+    s = Cosine.new()
+    s = Cosine.add(s, "empty", [])
+    assert %Cosine{attributes_counter: 0, attributes_map: %{}, map: %{"empty" => []}} = s
+  end
+
+  test "between with identical entries" do
+    s = Cosine.new()
+    s = Cosine.add(s, "a", [{"attr", 1}])
+    s = Cosine.add(s, "b", [{"attr", 1}])
+    assert Cosine.between(s, "a", "b") == 1.0
+  end
+
+  test "stream" do
+    s = Cosine.new()
+    s = Cosine.add(s, "a", [{"attr", 1}])
+    s = Cosine.add(s, "b", [{"attr", 2}])
+    s = Cosine.add(s, "c", [{"attr", 3}])
+
+    result = Cosine.stream(s) |> Enum.to_list()
+    assert length(result) == 3
+    assert Enum.all?(result, fn {_, _, similarity} -> is_float(similarity) end)
+  end
 end