fix CoinGecko tests

apps/explorer/lib/explorer/exchange_rates/source/coin_gecko.ex

@@ -11,7 +11,7 @@ defmodule Explorer.ExchangeRates.Source.CoinGecko do
   @behaviour Source
 
   @impl Source
-  def format_data(data) do
+  def format_data(%{"market_data" => _} = data) do
     {:ok, price} = get_btc_price()
     btc_price = to_decimal(price)
 
@@ -41,6 +41,9 @@ defmodule Explorer.ExchangeRates.Source.CoinGecko do
     ]
   end
 
+  @impl Source
+  def format_data(_), do: []
+
   @impl Source
   def source_url do
     "#{base_url()}/coins/#{coin_id()}"

apps/explorer/test/explorer/exchange_rates/source/coin_gecko_test.exs

@@ -18,34 +18,6 @@ defmodule Explorer.ExchangeRates.Source.CoinGeckoTest do
   }
   """
 
-  @json_mkt_data """
-  [
-    {
-      "id": "poa-network",
-      "symbol": "poa",
-      "name": "POA Network",
-      "image": "https://assets.coingecko.com/coins/images/3157/large/poa.jpg?1520829019",
-      "current_price": 0.114782883773693,
-      "market_cap": 25248999.6735956,
-      "market_cap_rank": 185,
-      "total_volume": 2344442.13578437,
-      "high_24h": 0.115215129840519,
-      "low_24h": 0.101039753612939,
-      "price_change_24h": 0.0135970966607094,
-      "price_change_percentage_24h": 13.437753511298,
-      "market_cap_change_24h": 3058195.58191147,
-      "market_cap_change_percentage_24h": 13.7813644304017,
-      "circulating_supply": "219935174.0",
-      "total_supply": 252193195,
-      "ath": 0.935923393359191,
-      "ath_change_percentage": -87.731057963078,
-      "ath_date": "2018-05-10T09:45:31.809Z",
-      "roi": null,
-      "last_updated": "2018-10-23T01:25:31.764Z"
-    }
-  ]
-  """
-
   describe "format_data/1" do
     setup do
       bypass = Bypass.open()
@@ -59,31 +31,30 @@ defmodule Explorer.ExchangeRates.Source.CoinGeckoTest do
         Conn.resp(conn, 200, @json_btc_price)
       end)
 
-      {:ok, expected_date, 0} = "2018-10-23T01:25:31.764Z" |> DateTime.from_iso8601()
+      json_data =
+        "#{File.cwd!()}/test/support/fixture/exchange_rates/coin_gecko.json"
+        |> File.read!()
+        |> Jason.decode!()
 
       expected = [
         %Token{
-          available_supply: Decimal.new("252193195"),
-          total_supply: Decimal.new("252193195"),
-          btc_value: Decimal.new("0.00001753101509231471092879666458"),
+          available_supply: Decimal.new("220167621.0"),
+          total_supply: Decimal.new("252193195.0"),
+          btc_value: Decimal.new("0.000002055310963802830367634997491"),
           id: "poa-network",
-          last_updated: expected_date,
-          market_cap_usd: Decimal.new("25248999.6735956"),
+          last_updated: ~U[2019-08-21 08:36:49.371Z],
+          market_cap_usd: Decimal.new("2962791"),
           name: "POA Network",
-          symbol: "poa",
-          usd_value: Decimal.new("0.114782883773693"),
-          volume_24h_usd: Decimal.new("2344442.13578437")
+          symbol: "POA",
+          usd_value: Decimal.new("0.01345698"),
+          volume_24h_usd: Decimal.new("119946")
         }
       ]
 
-      assert expected == CoinGecko.format_data(@json_mkt_data)
+      assert expected == CoinGecko.format_data(json_data)
     end
 
-    test "returns nothing when given bad data", %{bypass: bypass} do
-      Bypass.expect(bypass, "GET", "/exchange_rates", fn conn ->
-        Conn.resp(conn, 200, @json_btc_price)
-      end)
-
+    test "returns nothing when given bad data" do
       bad_data = """
         [{"id": "poa-network"}]
       """