Initial commit

spec/services/tickers_service_spec.rb

@@ -0,0 +1,85 @@
+# frozen_string_literal: true
+
+describe TickersService, '#ticker' do
+  let(:market) { Market.all.sample.id.to_sym }
+  let(:service) { TickersService }
+  context 'no trades executed' do
+    let(:default) do
+      {
+        amount: '0.0',
+        avg_price: '0.0',
+        high: '0.0',
+        last: '0.0',
+        low: '0.0',
+        open: '0.0',
+        price_change_percent: '+0.00%',
+        volume: '0.0'
+      }
+    end
+
+    it 'returns zero tickers' do
+      expect(service[:btcusd].ticker.except(:at)).to eq default
+    end
+  end
+
+  context 'single trade executed during last 24 hours' do
+    after { delete_measurments('trades') }
+    let!(:trade) { create(:trade, :btcusd, price: 5, amount: 2) }
+
+    let(:ticker) do
+      {
+        amount: '2.0',
+        avg_price: '5.0',
+        high: '5.0',
+        last: '5.0',
+        low: '5.0',
+        open: '5.0',
+        price_change_percent: '+0.00%',
+        volume: '10.0'
+      }
+    end
+
+    before do
+      trade.write_to_influx
+    end
+
+    it 'returns trade price' do
+      expect(service[:btcusd].ticker.except(:at)).to eq(ticker)
+    end
+  end
+
+  context 'multiple trades executed during last 24 hours' do
+    after { delete_measurments('trades') }
+
+    let(:trades) do
+      [
+        create(:trade, :btcusd, price: 12.to_d, amount: 10.to_d),
+        create(:trade, :btcusd, price: 11.to_d, amount: 17.to_d),
+        create(:trade, :btcusd, price: 10.to_d, amount: 25.to_d),
+        create(:trade, :btcusd, price:  9.to_d, amount: 18.to_d),
+        create(:trade, :btcusd, price:  8.to_d, amount: 10.to_d)
+      ]
+    end
+
+    let(:ticker) do
+      {
+        amount: '80.0',
+        avg_price: '9.9875',
+        high: '12.0',
+        last: '8.0',
+        low: '8.0',
+        open: '12.0',
+        price_change_percent: '-33.33%',
+        volume: '799.0'
+      }
+    end
+
+    before do
+      trades.map(&:write_to_influx)
+    end
+
+    it 'returns trade price' do
+      expect(service[:btcusd].ticker.except(:at)).to eq(ticker)
+    end
+  end
+end