Fix tests

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

@@ -103,7 +103,7 @@ defmodule Explorer.Counters.AverageBlockTime do
         {sum + duration, count + 1}
       end)
 
-    average = sum / count
+    average = if count == 0, do: 0, else: sum / count
 
     average
     |> round()
@@ -115,8 +115,13 @@ defmodule Explorer.Counters.AverageBlockTime do
     |> Enum.reduce({[], nil, nil}, fn {block_number, timestamp}, {durations, last_block_number, last_timestamp} ->
       if last_timestamp do
         block_numbers_range = last_block_number - block_number
+
+        if block_numbers_range == 0 do
+          {durations, block_number, timestamp}
+        else
           duration = (last_timestamp - timestamp) / block_numbers_range
           {[duration | durations], block_number, timestamp}
+        end
       else
         {durations, block_number, timestamp}
       end

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

@@ -34,19 +34,27 @@ defmodule Explorer.Counters.AverageBlockTimeTest do
 
       first_timestamp = Timex.now()
 
-      insert(:block, number: block_number, consensus: true, timestamp: Timex.shift(first_timestamp, seconds: -100 - 3))
+      insert(:block, number: block_number, consensus: true, timestamp: Timex.shift(first_timestamp, seconds: -100 - 6))
+
+      insert(:block, number: block_number, consensus: false, timestamp: Timex.shift(first_timestamp, seconds: -100 - 12))
+
       insert(:block, number: block_number, consensus: false, timestamp: Timex.shift(first_timestamp, seconds: -100 - 9))
-      insert(:block, number: block_number, consensus: false, timestamp: Timex.shift(first_timestamp, seconds: -100 - 6))
+
+      insert(:block,
+        number: block_number + 1,
+        consensus: true,
+        timestamp: Timex.shift(first_timestamp, seconds: -100 - 3)
+      )
 
       Enum.each(1..100, fn i ->
         insert(:block,
-          number: block_number + i,
+          number: block_number + 1 + i,
           consensus: true,
-          timestamp: Timex.shift(first_timestamp, seconds: -(101 - i) - 9)
+          timestamp: Timex.shift(first_timestamp, seconds: -(101 - i) - 12)
         )
       end)
 
-      assert Repo.aggregate(Block, :count, :hash) == 103
+      assert Repo.aggregate(Block, :count, :hash) == 104
 
       AverageBlockTime.refresh()