Add timestamps to both Flag and Gate

This is an improvement on [tompave#195](tompave#195). It adds the inserted_at and updated_at timestamps to the Gate structs, as well as a `last_modified_at` on the Flag itself which is the max of all gates' updated_at timestamps.

Author: s3cur3

lib/fun_with_flags/flag.ex

@@ -7,17 +7,29 @@ defmodule FunWithFlags.Flag do
 
   alias FunWithFlags.Gate
 
-  defstruct [name: nil, gates: []]
-  @type t :: %FunWithFlags.Flag{name: atom, gates: [FunWithFlags.Gate.t]}
-  @typep options :: Keyword.t
+  defstruct name: nil, gates: [], last_modified_at: nil
 
+  @type t :: %FunWithFlags.Flag{
+          name: atom,
+          gates: [FunWithFlags.Gate.t()],
+          last_modified_at: DateTime.t() | nil
+        }
+  @typep options :: Keyword.t()
 
   @doc false
   def new(name, gates \\ []) when is_atom(name) do
-    %__MODULE__{name: name, gates: gates}
+    last_modified_at =
+      gates
+      |> Enum.map(& &1.updated_at)
+      |> Enum.reject(&is_nil/1)
+      |> case do
+        [] -> nil
+        dates -> Enum.max(dates)
+      end
+
+    %__MODULE__{name: name, gates: gates, last_modified_at: last_modified_at}
   end
 
-
   @doc false
   @spec enabled?(t, options) :: boolean
   def enabled?(flag, options \\ [])

lib/fun_with_flags/gate.ex

@@ -16,10 +16,17 @@ defmodule FunWithFlags.Gate do
     defexception [:message]
   end
 
+  defstruct [:type, :for, :enabled, inserted_at: nil, updated_at: nil]
 
-  defstruct [:type, :for, :enabled]
-  @type t :: %FunWithFlags.Gate{type: atom, for: (nil | String.t), enabled: boolean}
-  @typep options :: Keyword.t
+  @type t :: %FunWithFlags.Gate{
+          type: atom,
+          for: nil | String.t(),
+          enabled: boolean,
+          inserted_at: DateTime.t() | nil,
+          updated_at: DateTime.t() | nil
+        }
+
+  @typep options :: Keyword.t()
 
   @doc false
   @spec new(atom, boolean | float) :: t

lib/fun_with_flags/store/persistent/ecto/record.ex

@@ -13,6 +13,7 @@ defmodule FunWithFlags.Store.Persistent.Ecto.Record do
     field :gate_type, :string
     field :target, :string
     field :enabled, :boolean
+    timestamps(type: :utc_datetime)
   end
 
   @fields [:flag_name, :gate_type, :target, :enabled]

lib/fun_with_flags/store/serializer/ecto.ex

@@ -26,24 +26,24 @@ defmodule FunWithFlags.Store.Serializer.Ecto do
   def deserialize_gate(_flag_name, _record), do: nil
 
 
-  defp do_deserialize_gate(%Record{gate_type: "boolean", enabled: enabled}) do
-    %Gate{type: :boolean, for: nil, enabled: enabled}
+  defp do_deserialize_gate(%Record{gate_type: "boolean", enabled: enabled} = record) do
+    %Gate{type: :boolean, for: nil, enabled: enabled, inserted_at: record.inserted_at, updated_at: record.updated_at}
   end
 
-  defp do_deserialize_gate(%Record{gate_type: "actor", enabled: enabled, target: target}) do
-    %Gate{type: :actor, for: target, enabled: enabled}
+  defp do_deserialize_gate(%Record{gate_type: "actor", enabled: enabled, target: target} = record) do
+    %Gate{type: :actor, for: target, enabled: enabled, inserted_at: record.inserted_at, updated_at: record.updated_at}
   end
 
-  defp do_deserialize_gate(%Record{gate_type: "group", enabled: enabled, target: target}) do
-    %Gate{type: :group, for: target, enabled: enabled}
+  defp do_deserialize_gate(%Record{gate_type: "group", enabled: enabled, target: target} = record) do
+    %Gate{type: :group, for: target, enabled: enabled, inserted_at: record.inserted_at, updated_at: record.updated_at}
   end
 
-  defp do_deserialize_gate(%Record{gate_type: "percentage", target: "time/" <> ratio_s}) do
-    %Gate{type: :percentage_of_time, for: parse_float(ratio_s), enabled: true}
+  defp do_deserialize_gate(%Record{gate_type: "percentage", target: "time/" <> ratio_s} = record) do
+    %Gate{type: :percentage_of_time, for: parse_float(ratio_s), enabled: true, inserted_at: record.inserted_at, updated_at: record.updated_at}
   end
 
-  defp do_deserialize_gate(%Record{gate_type: "percentage", target: "actors/" <> ratio_s}) do
-    %Gate{type: :percentage_of_actors, for: parse_float(ratio_s), enabled: true}
+  defp do_deserialize_gate(%Record{gate_type: "percentage", target: "actors/" <> ratio_s} = record) do
+    %Gate{type: :percentage_of_actors, for: parse_float(ratio_s), enabled: true, inserted_at: record.inserted_at, updated_at: record.updated_at}
   end
 
   def to_atom(atm) when is_atom(atm), do: atm

priv/ecto_repo/migrations/00000000000001_add_timestamps.exs

@@ -0,0 +1,14 @@
+defmodule FunWithFlags.Dev.EctoRepo.Migrations.CreateFeatureFlagsTable do
+  use Ecto.Migration
+
+  # This migration assumes the default table name of "fun_with_flags_toggles"
+  # is being used. If you have overridden that via configuration, you should
+  # change this migration accordingly.
+
+  def change do
+    alter table(:fun_with_flags_toggles) do
+      add :inserted_at, :utc_datetime, null: false, default: fragment("CURRENT_TIMESTAMP")
+      add :updated_at, :utc_datetime, null: false, default: fragment("CURRENT_TIMESTAMP")
+    end
+  end
+end

test/fun_with_flags/notifications/phoenix_pubsub_test.exs

@@ -169,17 +169,21 @@ defmodule FunWithFlags.Notifications.PhoenixPubSubTest do
     setup do
       name = unique_atom()
       gate = %Gate{type: :boolean, enabled: true}
-      stored_flag = %Flag{name: name, gates: [gate]}
+      expected_stored_flag = %Flag{name: name, gates: [gate]}
 
       gate2 = %Gate{type: :boolean, enabled: false}
       cached_flag = %Flag{name: name, gates: [gate2]}
 
-      {:ok, ^stored_flag} = Config.persistence_adapter.put(name, gate)
+      {:ok, stored_flag} = Config.persistence_adapter.put(name, gate)
+      assert drop_timestamps(stored_flag) == expected_stored_flag
+
       assert_with_retries(fn ->
-        {:ok, ^cached_flag} = Cache.put(cached_flag)
+        {:ok, put} = Cache.put(cached_flag)
+        assert drop_timestamps(put) == drop_timestamps(cached_flag)
       end)
 
-      assert {:ok, ^stored_flag} = Config.persistence_adapter.get(name)
+      {:ok, persisted} = Config.persistence_adapter.get(name)
+      assert drop_timestamps(persisted) == expected_stored_flag
       assert {:ok, ^cached_flag} = Cache.get(name)
 
       wait_until_pubsub_is_ready!()
@@ -190,7 +194,7 @@ defmodule FunWithFlags.Notifications.PhoenixPubSubTest do
     # This should be in `setup` but in there it produces a compiler warning because
     # the two variables will never match (duh).
     test "verify test setup", %{cached_flag: cached_flag, stored_flag: stored_flag} do
-      refute match? ^stored_flag, cached_flag
+      refute match? ^stored_flag, drop_timestamps(cached_flag)
     end
 
 
@@ -203,7 +207,8 @@ defmodule FunWithFlags.Notifications.PhoenixPubSubTest do
       Phoenix.PubSub.broadcast!(client, channel, message)
 
       assert_with_retries(fn ->
-        assert {:ok, ^cached_flag} = Cache.get(name)
+        assert {:ok, put} = Cache.get(name)
+        assert drop_timestamps(put) == drop_timestamps(cached_flag)
       end)
     end
 
@@ -220,8 +225,17 @@ defmodule FunWithFlags.Notifications.PhoenixPubSubTest do
       Phoenix.PubSub.broadcast!(client, channel, message)
 
       assert_with_retries(fn ->
-        assert {:ok, ^stored_flag} = Cache.get(name)
+        assert {:ok, result} = Cache.get(name)
+        assert drop_timestamps(result) == drop_timestamps(stored_flag)
       end)
     end
   end
+
+  defp drop_timestamps(%FunWithFlags.Gate{} = gate) do
+    %{gate | inserted_at: nil, updated_at: nil}
+  end
+
+  defp drop_timestamps(%FunWithFlags.Flag{} = flag) do
+    %{flag | last_modified_at: nil, gates: Enum.map(flag.gates, &drop_timestamps/1)}
+  end
 end

test/fun_with_flags/simple_store_test.exs

@@ -26,16 +26,22 @@ defmodule FunWithFlags.SimpleStoreTest do
       assert {:ok, %Flag{name: ^name, gates: []}} = SimpleStore.lookup(name)
 
       SimpleStore.put(name, gate)
-      assert {:ok, %Flag{name: ^name, gates: [^gate]}} = SimpleStore.lookup(name)
+      {:ok, result} = SimpleStore.lookup(name)
+      assert %Flag{name: ^name} = result
+      assert [persisted_gate] = result.gates
+      assert drop_timestamps(persisted_gate) == gate
 
       gate2 = %Gate{gate | enabled: false}
       SimpleStore.put(name, gate2)
-      assert {:ok, %Flag{name: ^name, gates: [^gate2]}} = SimpleStore.lookup(name)
-      refute match? {:ok, %Flag{name: ^name, gates: [^gate]}}, SimpleStore.lookup(name)
+      {:ok, result2} = SimpleStore.lookup(name)
+      assert %Flag{name: ^name} = result2
+      assert [persisted_gate2] = result2.gates
+      assert drop_timestamps(persisted_gate2) == gate2
     end
 
     test "put() returns the tuple {:ok, %Flag{}}", %{name: name, gate: gate, flag: flag} do
-      assert {:ok, ^flag} = SimpleStore.put(name, gate)
+      {:ok, result} = SimpleStore.put(name, gate)
+      assert drop_timestamps(result) == flag
     end
 
     @tag :telemetry
@@ -91,27 +97,45 @@ defmodule FunWithFlags.SimpleStoreTest do
       SimpleStore.put(name, bool_gate)
       SimpleStore.put(name, group_gate)
       {:ok, flag} = SimpleStore.lookup(name)
-      assert %Flag{name: ^name, gates: [^bool_gate, ^group_gate]} = flag
+      assert %Flag{name: ^name} = flag
+      assert [persisted_bool, persisted_group] = flag.gates
+      assert drop_timestamps(persisted_bool) == bool_gate
+      assert drop_timestamps(persisted_group) == group_gate
 
-      {:ok, name: name, bool_gate: bool_gate, group_gate: group_gate}
+      {:ok, name: name, bool_gate: persisted_bool, group_gate: persisted_group}
     end
 
     test "delete(flag_name, gate) can change the value of a flag", %{name: name, bool_gate: bool_gate, group_gate: group_gate} do
-      assert {:ok, %Flag{name: ^name, gates: [^bool_gate, ^group_gate]}} = SimpleStore.lookup(name)
+      {:ok, flag} = SimpleStore.lookup(name)
+      assert %Flag{name: ^name} = flag
+      assert length(flag.gates) == 2
 
       SimpleStore.delete(name, bool_gate)
-      assert {:ok, %Flag{name: ^name, gates: [^group_gate]}} = SimpleStore.lookup(name)
+      {:ok, flag2} = SimpleStore.lookup(name)
+      assert %Flag{name: ^name} = flag2
+      assert [remaining_gate] = flag2.gates
+      assert drop_timestamps(remaining_gate) == drop_timestamps(group_gate)
+
       SimpleStore.delete(name, group_gate)
       assert {:ok, %Flag{name: ^name, gates: []}} = SimpleStore.lookup(name)
     end
 
     test "delete(flag_name, gate) returns the tuple {:ok, %Flag{}}", %{name: name, bool_gate: bool_gate, group_gate: group_gate} do
-      assert {:ok, %Flag{name: ^name, gates: [^group_gate]}} = SimpleStore.delete(name, bool_gate)
+      {:ok, result} = SimpleStore.delete(name, bool_gate)
+      assert %Flag{name: ^name} = result
+      assert [remaining_gate] = result.gates
+      assert drop_timestamps(remaining_gate) == drop_timestamps(group_gate)
     end
 
     test "deleting is safe and idempotent", %{name: name, bool_gate: bool_gate, group_gate: group_gate} do
-      assert {:ok, %Flag{name: ^name, gates: [^group_gate]}} = SimpleStore.delete(name, bool_gate)
-      assert {:ok, %Flag{name: ^name, gates: [^group_gate]}} = SimpleStore.delete(name, bool_gate)
+      {:ok, result1} = SimpleStore.delete(name, bool_gate)
+      assert [g1] = result1.gates
+      assert drop_timestamps(g1) == drop_timestamps(group_gate)
+
+      {:ok, result2} = SimpleStore.delete(name, bool_gate)
+      assert [g2] = result2.gates
+      assert drop_timestamps(g2) == drop_timestamps(group_gate)
+
       assert {:ok, %Flag{name: ^name, gates: []}} = SimpleStore.delete(name, group_gate)
       assert {:ok, %Flag{name: ^name, gates: []}} = SimpleStore.delete(name, group_gate)
     end
@@ -169,13 +193,18 @@ defmodule FunWithFlags.SimpleStoreTest do
       SimpleStore.put(name, bool_gate)
       SimpleStore.put(name, group_gate)
       {:ok, flag} = SimpleStore.lookup(name)
-      assert %Flag{name: ^name, gates: [^bool_gate, ^group_gate]} = flag
+      assert %Flag{name: ^name} = flag
+      assert [persisted_bool, persisted_group] = flag.gates
+      assert drop_timestamps(persisted_bool) == bool_gate
+      assert drop_timestamps(persisted_group) == group_gate
 
-      {:ok, name: name, bool_gate: bool_gate, group_gate: group_gate}
+      {:ok, name: name, bool_gate: persisted_bool, group_gate: persisted_group}
     end
 
-    test "delete(flag_name) will reset all the flag gates", %{name: name, bool_gate: bool_gate, group_gate: group_gate} do
-      assert {:ok, %Flag{name: ^name, gates: [^bool_gate, ^group_gate]}} = SimpleStore.lookup(name)
+    test "delete(flag_name) will reset all the flag gates", %{name: name} do
+      {:ok, flag} = SimpleStore.lookup(name)
+      assert %Flag{name: ^name} = flag
+      assert length(flag.gates) == 2
 
       SimpleStore.delete(name)
       assert {:ok, %Flag{name: ^name, gates: []}} = SimpleStore.lookup(name)
@@ -246,7 +275,10 @@ defmodule FunWithFlags.SimpleStoreTest do
 
       assert {:ok, %Flag{name: ^name, gates: []}} = SimpleStore.lookup(name)
       SimpleStore.put(name, gate)
-      assert {:ok, %Flag{name: ^name, gates: [^gate]}} = SimpleStore.lookup(name)
+      {:ok, result} = SimpleStore.lookup(name)
+      assert %Flag{name: ^name} = result
+      assert [persisted_gate] = result.gates
+      assert drop_timestamps(persisted_gate) == gate
     end
 
     @tag :telemetry
@@ -327,12 +359,14 @@ defmodule FunWithFlags.SimpleStoreTest do
       {:ok, result} = SimpleStore.all_flags()
       assert 3 = length(result)
 
+      result_without_timestamps = Enum.map(result, &drop_timestamps/1)
+
       for flag <- [
         %Flag{name: name1, gates: [g_1a, g_1b, g_1c]},
         %Flag{name: name2, gates: [g_2a, g_2b]},
         %Flag{name: name3, gates: [g_3a]}
       ] do
-        assert flag in result
+        assert flag in result_without_timestamps
       end
     end
 
@@ -531,4 +565,12 @@ defmodule FunWithFlags.SimpleStoreTest do
       end
     end
   end
+
+  defp drop_timestamps(%Gate{} = gate) do
+    %{gate | inserted_at: nil, updated_at: nil}
+  end
+
+  defp drop_timestamps(%Flag{} = flag) do
+    %{flag | last_modified_at: nil, gates: Enum.map(flag.gates, &drop_timestamps/1)}
+  end
 end