Use floats for all gas values (#642)

Author: ansermino

connections/ethereum/connection.go

@@ -138,7 +138,7 @@ func (c *Connection) SafeEstimateGas(ctx context.Context) (*big.Int, error) {
 	if c.egsApiKey != "" {
 		price, err := egs.FetchGasPrice(c.egsApiKey, c.egsSpeed)
 		if err != nil {
-			c.log.Debug("Couldn't fetch gasPrice from GSN", err)
+			c.log.Error("Couldn't fetch gasPrice from GSN", "err", err)
 		} else {
 			suggestedGasPrice = price
 		}

connections/ethereum/egs/egs.go

@@ -24,10 +24,10 @@ const (
 )
 
 type gasPriceResponse struct {
-	Fast          int64       `json:"fast"`
-	Fastest       int64       `json:"fastest"`
-	SafeLow       int64       `json:"safeLow"`
-	Average       int64       `json:"average"`
+	Fast          float32     `json:"fast"`
+	Fastest       float32     `json:"fastest"`
+	SafeLow       float32     `json:"safeLow"`
+	Average       float32     `json:"average"`
 	BlockTime     float32     `json:"block_time"`
 	BlockNum      int64       `json:"blockNum"`
 	Speed         float32     `json:"speed"`
@@ -92,14 +92,19 @@ func parsePrice(result *gasPriceResponse, speed string) *big.Int {
 	var res *big.Int
 	switch speed {
 	case Fastest:
-		res = big.NewInt(result.Fastest)
+		res = big.NewInt(int64(result.Fastest))
 	case Fast:
-		res = big.NewInt(result.Fast)
+		res = big.NewInt(int64(result.Fast))
 	case Average:
-		res = big.NewInt(result.Average)
+		res = big.NewInt(int64(result.Average))
 	default:
-		res = big.NewInt(result.Fast)
+		res = big.NewInt(int64(result.Fast))
 	}
+	// Make sure we get at least 10 gwei to avoid prices of 0
+	if res.Cmp(big.NewInt(1)) == -1 {
+		res = big.NewInt(1)
+	}
+
 	base := big.NewInt(8) // we are using 8 here but not 9 bcs ethgas station returns values in Gwei * 10
 	return res.Mul(res, big.NewInt(0).Exp(big.NewInt(10), base, nil))
 }

connections/ethereum/egs/egs_test.go

@@ -20,7 +20,7 @@ var exampleResponse = &gasPriceResponse{
 }
 
 // Captured by querying endpoint manually
-var rawResponse = "{\"fast\":590,\"fastest\":700,\"safeLow\":490,\"average\":500,\"block_time\":15.9,\"blockNum\":12389059,\"speed\":0.995538884040233,\"safeLowWait\":13.6,\"avgWait\":2.1,\"fastWait\":0.9,\"fastestWait\":0.6,\"gasPriceRange\":{\"4\":265,\"6\":265,\"8\":265,\"10\":265,\"20\":265,\"30\":265,\"40\":265,\"50\":265,\"60\":265,\"70\":265,\"80\":265,\"90\":265,\"100\":265,\"110\":265,\"120\":265,\"130\":265,\"140\":265,\"150\":265,\"160\":265,\"170\":265,\"180\":265,\"190\":265,\"200\":265,\"220\":265,\"240\":265,\"260\":265,\"280\":265,\"300\":265,\"320\":265,\"340\":265,\"360\":265,\"380\":265,\"400\":265,\"420\":265,\"440\":265,\"460\":265,\"480\":15,\"490\":13.6,\"500\":2.1,\"520\":1.7,\"540\":1.2,\"560\":1,\"580\":0.9,\"590\":0.9,\"600\":0.8,\"620\":0.7,\"640\":0.7,\"660\":0.7,\"680\":0.7,\"700\":0.6}}"
+var rawResponse = "{\"fast\":590,\"fastest\":700,\"safeLow\":490,\"average\":0.5,\"block_time\":15.9,\"blockNum\":12389059,\"speed\":0.995538884040233,\"safeLowWait\":13.6,\"avgWait\":2.1,\"fastWait\":0.9,\"fastestWait\":0.6,\"gasPriceRange\":{\"4\":265,\"6\":265,\"8\":265,\"10\":265,\"20\":265,\"30\":265,\"40\":265,\"50\":265,\"60\":265,\"70\":265,\"80\":265,\"90\":265,\"100\":265,\"110\":265,\"120\":265,\"130\":265,\"140\":265,\"150\":265,\"160\":265,\"170\":265,\"180\":265,\"190\":265,\"200\":265,\"220\":265,\"240\":265,\"260\":265,\"280\":265,\"300\":265,\"320\":265,\"340\":265,\"360\":265,\"380\":265,\"400\":265,\"420\":265,\"440\":265,\"460\":265,\"480\":15,\"490\":13.6,\"500\":2.1,\"520\":1.7,\"540\":1.2,\"560\":1,\"580\":0.9,\"590\":0.9,\"600\":0.8,\"620\":0.7,\"640\":0.7,\"660\":0.7,\"680\":0.7,\"700\":0.6}}"
 
 func TestParsePrice(t *testing.T) {
 	assert.Equal(t, parsePrice(exampleResponse, Fastest), big.NewInt(200000000))