feat: render block time with up to one decimal point of accuracy

apps/block_scout_web/lib/block_scout_web/channels/block_channel.ex

@@ -36,7 +36,7 @@ defmodule BlockScoutWeb.BlockChannel do
       )
 
     push(socket, "new_block", %{
-      average_block_time: Timex.format_duration(average_block_time, :humanized),
+      average_block_time: Timex.format_duration(average_block_time, Explorer.Counters.AverageBlockTimeDurationFormat),
       chain_block_html: rendered_chain_block,
       block_html: rendered_block,
       block_number: block.number,

apps/block_scout_web/lib/block_scout_web/templates/chain/show.html.eex

@@ -41,7 +41,7 @@
                 <%= gettext "Average block time" %>
               </span>
               <span class="dashboard-banner-network-stats-value" data-selector="average-block-time">
-                <%= Timex.format_duration(average_block_time, :humanized) %>
+                <%= Timex.format_duration(average_block_time, Explorer.Counters.AverageBlockTimeDurationFormat) %>
               </span>
             </div>
         <% end %>

apps/explorer/lib/explorer/counters/average_block_time.ex

@@ -26,7 +26,7 @@ defmodule Explorer.Counters.AverageBlockTime do
       |> Keyword.fetch!(:enabled)
 
     if enabled? do
-      block = if block, do: {block.number, DateTime.to_unix(block.timestamp)}
+      block = if block, do: {block.number, DateTime.to_unix(block.timestamp, :millisecond)}
       GenServer.call(__MODULE__, {:average_block_time, block})
     else
       {:error, :disabled}
@@ -48,7 +48,7 @@ defmodule Explorer.Counters.AverageBlockTime do
       timestamps_query
       |> Repo.all()
       |> Enum.map(fn {number, timestamp} ->
-        {number, DateTime.to_unix(timestamp)}
+        {number, DateTime.to_unix(timestamp, :millisecond)}
       end)
 
     {:ok, %{timestamps: timestamps, average: average_distance(timestamps)}}
@@ -73,8 +73,8 @@ defmodule Explorer.Counters.AverageBlockTime do
     %{state | timestamps: timestamps, average: average_distance(timestamps)}
   end
 
-  defp average_distance([]), do: Duration.from_seconds(0)
-  defp average_distance([_]), do: Duration.from_seconds(0)
+  defp average_distance([]), do: Duration.from_milliseconds(0)
+  defp average_distance([_]), do: Duration.from_milliseconds(0)
 
   defp average_distance(timestamps) do
     durations = durations(timestamps)
@@ -88,7 +88,7 @@ defmodule Explorer.Counters.AverageBlockTime do
 
     average
     |> round()
-    |> Duration.from_seconds()
+    |> Duration.from_milliseconds()
   end
 
   defp durations(timestamps) do

apps/explorer/lib/explorer/counters/average_block_time_duration_format.ex

@@ -0,0 +1,99 @@
+defmodule Explorer.Counters.AverageBlockTimeDurationFormat do
+  @moduledoc """
+  A `Timex.Format.Duration.Formatter` that renders the most significant unit out to one decimal point.
+  """
+
+  use Timex.Format.Duration.Formatter
+  alias Timex.Translator
+
+  @millisecond 1
+  @second @millisecond * 1000
+  @minute @second * 60
+  @hour @minute * 60
+  @day @hour * 24
+  @week @day * 7
+  @month @day * 30
+  @year @day * 365
+
+  @unit_term_mapping [
+    {@year, "year"},
+    {@month, "month"},
+    {@week, "week"},
+    {@day, "day"},
+    {@hour, "hour"},
+    {@minute, "minute"},
+    {@second, "second"},
+    {@millisecond, "millisecond"}
+  ]
+
+  @doc """
+  Formats a duration as a single value and a decimal part.
+
+  See `lformat/2` for more information.
+
+      iex> use Timex
+      ...> Duration.from_erl({0, 65, 0}) |> #{__MODULE__}.format()
+      "1.1 minutes"
+  """
+  @spec format(Duration.t()) :: String.t() | {:error, term}
+  def format(%Duration{} = duration), do: lformat(duration, Translator.default_locale())
+  def format(_), do: {:error, :invalid_duration}
+
+  @doc """
+  Formats a duration as a single value and a decimal part.
+
+  Chooses the greatest whole unit available from:
+
+  * year
+  * month
+  * week
+  * day
+  * hour
+  * minute
+  * second
+  * millisecond
+
+  Accepts a translation locale and honors it for the units.
+
+      iex> use Timex
+      ...> Duration.from_erl({0, 65, 0}) |> #{__MODULE__}.lformat("en")
+      "1.1 minutes"
+
+      iex> use Timex
+      ...> Duration.from_erl({0, 0, 0}) |> #{__MODULE__}.lformat("en")
+      "0 milliseconds"
+  """
+  def lformat(%Duration{} = duration, locale) do
+    duration
+    |> Duration.to_milliseconds()
+    |> round()
+    |> do_format(locale)
+  end
+
+  def lformat(_, _locale), do: {:error, :invalid_duration}
+
+  defp do_format(0, locale) do
+    Translator.translate_plural(locale, "units", "%{count}, millisecond", "%{count} milliseconds", 0)
+  end
+
+  for {unit, name} <- @unit_term_mapping do
+    defp do_format(value, locale) when value >= unquote(unit) do
+      format_unit(locale, unquote(unit), value, unquote(name))
+    end
+  end
+
+  defp format_unit(locale, unit, value, singular) do
+    decimal_value = value / unit
+    truncated = trunc(decimal_value)
+
+    # remove any trailing `.0`
+    formatted_value =
+      if decimal_value == truncated do
+        truncated
+      else
+        Float.round(decimal_value, 1)
+      end
+
+    Translator.translate_plural(locale, "units", "%{count} #{singular}", "%{count} #{singular}s", formatted_value)
+  end
+end

apps/explorer/test/explorer/counters/average_block_time_test.exs

@@ -1,6 +1,8 @@
 defmodule Explorer.Counters.AverageBlockTimeTest do
   use Explorer.DataCase
 
+  doctest Explorer.Counters.AverageBlockTimeDurationFormat
+
   alias Explorer.Counters.AverageBlockTime
 
   defp block(number, last, duration), do: %{number: number, timestamp: Timex.shift(last, seconds: duration)}