Refactor percentage helper and extract it to Plausible.Stats.Util

Author: zoldar

extra/lib/plausible/stats/funnel.ex

@@ -11,6 +11,7 @@ defmodule Plausible.Stats.Funnel do
 
   import Ecto.Query
   import Plausible.Stats.SQL.Fragments
+  import Plausible.Stats.Util, only: [percentage: 2]
 
   alias Plausible.ClickhouseRepo
   alias Plausible.Stats.{Base, Query}
@@ -167,24 +168,4 @@ defmodule Plausible.Stats.Funnel do
     |> elem(2)
     |> Enum.reverse()
   end
-
-  defp percentage(x, y) when x in [0, nil] or y in [0, nil] do
-    "0"
-  end
-
-  defp percentage(x, y) do
-    result =
-      x
-      |> Decimal.div(y)
-      |> Decimal.mult(100)
-      |> Decimal.round(2)
-      |> Decimal.to_string()
-
-    case result do
-      <<compact::binary-size(1), ".00">> -> compact
-      <<compact::binary-size(2), ".00">> -> compact
-      <<compact::binary-size(3), ".00">> -> compact
-      decimal -> decimal
-    end
-  end
 end

lib/plausible/stats/exploration.ex

@@ -14,6 +14,7 @@ defmodule Plausible.Stats.Exploration do
 
   import Ecto.Query
   import Plausible.Stats.SQL.Fragments
+  import Plausible.Stats.Util, only: [percentage: 2]
 
   alias Plausible.ClickhouseRepo
   alias Plausible.Stats.Base
@@ -240,24 +241,4 @@ defmodule Plausible.Stats.Exploration do
     |> Map.fetch!(:funnel)
     |> Enum.reverse()
   end
-
-  defp percentage(x, y) when x in [0, nil] or y in [0, nil] do
-    "0"
-  end
-
-  defp percentage(x, y) do
-    result =
-      x
-      |> Decimal.div(y)
-      |> Decimal.mult(100)
-      |> Decimal.round(2)
-      |> Decimal.to_string()
-
-    case result do
-      <<compact::binary-size(1), ".00">> -> compact
-      <<compact::binary-size(2), ".00">> -> compact
-      <<compact::binary-size(3), ".00">> -> compact
-      decimal -> decimal
-    end
-  end
 end

lib/plausible/stats/util.ex

@@ -29,4 +29,24 @@ defmodule Plausible.Stats.Util do
     index = Enum.find_index(query.dimensions, &(&1 == dimension))
     :"dim#{index}"
   end
+
+  def percentage(x, y) when is_integer(x) and x > 0 and is_integer(y) and y > 0 do
+    result =
+      x
+      |> Decimal.div(y)
+      |> Decimal.mult(100)
+      |> Decimal.round(2)
+      |> Decimal.to_string()
+
+    case result do
+      <<compact::binary-size(1), ".00">> -> compact
+      <<compact::binary-size(2), ".00">> -> compact
+      <<compact::binary-size(3), ".00">> -> compact
+      decimal -> decimal
+    end
+  end
+
+  def percentage(_x, _y) do
+    "0"
+  end
 end