fix market history overriding

apps/explorer/lib/explorer/market/history/source/crypto_compare.ex

@@ -48,6 +48,7 @@ defmodule Explorer.Market.History.Source.CryptoCompare do
   defp format_data(data) do
     json = Jason.decode!(data)
 
+    items =
       for item <- json["Data"] do
         %{
           closing_price: Decimal.new(to_string(item["close"])),
@@ -55,6 +56,10 @@ defmodule Explorer.Market.History.Source.CryptoCompare do
           opening_price: Decimal.new(to_string(item["open"]))
         }
       end
+
+    Enum.reject(items, fn item ->
+      Decimal.equal?(item.closing_price, 0) && Decimal.equal?(item.opening_price, 0)
+    end)
   end
 
   @spec history_url(non_neg_integer()) :: String.t()

apps/explorer/lib/explorer/market/market.ex

@@ -40,7 +40,12 @@ defmodule Explorer.Market do
 
   @doc false
   def bulk_insert_history(records) do
-    Repo.insert_all(MarketHistory, records, on_conflict: :replace_all, conflict_target: [:date])
+    records_without_zeroes =
+      Enum.reject(records, fn item ->
+        Decimal.equal?(item.closing_price, 0) && Decimal.equal?(item.opening_price, 0)
+      end)
+
+    Repo.insert_all(MarketHistory, records_without_zeroes, on_conflict: :replace_all, conflict_target: [:date])
   end
 
   def add_price(%{symbol: symbol} = token) do

apps/explorer/test/explorer/market/history/source/crypto_compare_test.exs

@@ -86,5 +86,59 @@ defmodule Explorer.Market.History.Source.CryptoCompareTest do
 
       assert :error == CryptoCompare.fetch_history(3)
     end
+
+    test "rejects empty prices", %{bypass: bypass} do
+      json = """
+      {
+        "Response": "Success",
+        "Type": 100,
+        "Aggregated": false,
+        "Data": [
+          {
+            "time": 1524528000,
+            "close": 0,
+            "high": 9741.91,
+            "low": 8957.68,
+            "open": 0,
+            "volumefrom": 136352.05,
+            "volumeto": 1276464750.74
+          },
+          {
+            "time": 1524614400,
+            "close": 0,
+            "high": 9765.23,
+            "low": 8757.06,
+            "open": 0,
+            "volumefrom": 192797.41,
+            "volumeto": 1779806222.98
+          },
+          {
+            "time": 1524700800,
+            "close": 8804.32,
+            "high": 8965.84,
+            "low": 8669.38,
+            "open": 8873.57,
+            "volumefrom": 74704.5,
+            "volumeto": 661168891
+          }
+        ],
+        "TimeTo": 1524700800,
+        "TimeFrom": 1523836800,
+        "FirstValueInArray": true,
+        "ConversionType": {
+          "type": "direct",
+          "conversionSymbol": ""
+        }
+      }
+      """
+
+      Bypass.expect(bypass, fn conn -> Conn.resp(conn, 200, json) end)
+
+      expected = [
+        %{closing_price: Decimal.from_float(8804.32), date: ~D[2018-04-26], opening_price: Decimal.from_float(8873.57)}
+      ]
+
+      assert {:ok, expected} == CryptoCompare.fetch_history(3)
+    end
   end
 end

apps/explorer/test/explorer/market/market_test.exs

@@ -72,6 +72,25 @@ defmodule Explorer.MarketTest do
       assert missing_records == %{}
     end
 
+    test "doesn't replace existing records with zeros" do
+      date = ~D[2018-04-01]
+
+      {:ok, old_record} =
+        Repo.insert(%MarketHistory{date: date, closing_price: Decimal.new(1), opening_price: Decimal.new(1)})
+
+      new_record = %{
+        date: date,
+        closing_price: Decimal.new(0),
+        opening_price: Decimal.new(0)
+      }
+
+      Market.bulk_insert_history([new_record])
+
+      fetched_record = Repo.get_by(MarketHistory, date: date)
+      assert fetched_record.closing_price == old_record.closing_price
+      assert fetched_record.opening_price == old_record.opening_price
+    end
+
     test "overrides existing records on date conflict" do
       date = ~D[2018-04-01]
       Repo.insert(%MarketHistory{date: date})