add today's token balance from previous value

apps/explorer/lib/explorer/chain.ex

@@ -2613,11 +2613,20 @@ defmodule Explorer.Chain do
   end
 
   defp normalize_balances_by_day(balances_by_day) do
-    balances_by_day
-    |> Enum.map(fn day -> Map.take(day, [:date, :value]) end)
-    |> Enum.filter(fn day -> day.value end)
-    |> Enum.map(fn day -> Map.update!(day, :date, &to_string(&1)) end)
-    |> Enum.map(fn day -> Map.update!(day, :value, &Wei.to(&1, :ether)) end)
+    result =
+      balances_by_day
+      |> Enum.map(fn day -> Map.take(day, [:date, :value]) end)
+      |> Enum.filter(fn day -> day.value end)
+      |> Enum.map(fn day -> Map.update!(day, :date, &to_string(&1)) end)
+      |> Enum.map(fn day -> Map.update!(day, :value, &Wei.to(&1, :ether)) end)
+
+    today = Date.to_string(NaiveDateTime.utc_now())
+
+    if Enum.count(result) > 0 && !Enum.any?(result, fn map -> map[:data] == today end) do
+      result ++ [%{date: today, value: List.last(result)[:value]}]
+    else
+      result
+    end
   end
 
   @spec fetch_token_holders_from_token_hash(Hash.Address.t(), [paging_options]) :: [TokenBalance.t()]

apps/explorer/test/explorer/chain_test.exs

@@ -3665,6 +3665,22 @@ defmodule Explorer.ChainTest do
                %{date: today |> NaiveDateTime.to_date() |> Date.to_string(), value: Decimal.new("1E-15")}
              ]
     end
+
+    test "adds todays entry" do
+      address = insert(:address)
+      today = NaiveDateTime.utc_now()
+      noon = Timex.set(today, hour: 12)
+      yesterday = Timex.shift(noon, days: -1)
+      block_one_day_ago = insert(:block, timestamp: yesterday)
+      insert(:fetched_balance, address_hash: address.hash, value: 1000, block_number: block_one_day_ago.number)
+
+      balances = Chain.address_to_balances_by_day(address.hash)
+
+      assert balances == [
+               %{date: "2019-04-14", value: Decimal.new("1E-15")},
+               %{date: "2019-04-15", value: Decimal.new("1E-15")}
+             ]
+    end
   end
 
   describe "block_combined_rewards/1" do