Improve logs

lib/tz/updater.ex

@@ -42,6 +42,10 @@ defmodule Tz.Updater do
       {:ok, latest_version} ->
         if latest_version != latest_version_saved &&
              latest_version != PeriodsProvider.iana_version() do
+          Logger.info(
+            "New IANA time zone data version #{latest_version} available; currently using #{latest_version_saved}."
+          )
+
           case update_tz_database(latest_version) do
             {:ok, _dir} ->
               IanaDataDir.delete_tzdata_dir(latest_version_saved)
@@ -51,6 +55,10 @@ defmodule Tz.Updater do
               {:error, latest_version_saved}
           end
         else
+          Logger.info(
+            "Already using the latest IANA time zone data version: #{PeriodsProvider.iana_version()}."
+          )
+
           {:already_latest, latest_version}
         end
 
@@ -68,7 +76,6 @@ defmodule Tz.Updater do
     case HTTP.get_http_client!().request("data.iana.org", "/time-zones/tzdb/version") do
       %HTTPResponse{body: body, status_code: 200} ->
         version = body |> String.trim()
-        Logger.info("Latest version of the IANA time zone data is #{version}")
         {:ok, version}
 
       _ ->

lib/tz/watch_periodically.ex

@@ -37,6 +37,10 @@ defmodule Tz.WatchPeriodically do
           )
 
           on_update_callback && on_update_callback.(latest_version)
+        else
+          Logger.info(
+            "Already using the latest IANA time zone data version: #{PeriodsProvider.iana_version()}."
+          )
         end
 
       :error ->

test/updater_test.exs

@@ -7,5 +7,7 @@ defmodule UpdaterTest do
 
     assert {:ok, _} = start_supervised(Tz.WatchPeriodically)
     assert {:error, _} = start_supervised(Tz.WatchPeriodically)
+
+    :timer.sleep(6_000)
   end
 end