Add etherscan gas price (#182)

* Add etherscan gas price

* Update Changelog

CHANGELOG.md

@@ -1,6 +1,7 @@
 
 # 0.1.1 (Not released)
 
+- Add `etherscan.GasPrice` function to return last block gas price [[GH-182](https://github.com/umbracle/ethgo/issues/182)]
 - Add `4byte` package and cli [[GH-178](https://github.com/umbracle/ethgo/issues/178)]
 - Install and use `ethers.js` spec tests for wallet private key decoding [[GH-177](https://github.com/umbracle/ethgo/issues/177)]
 - Add `GetLogs` function Etherscan to return logs by filter [[GH-170](https://github.com/umbracle/ethgo/issues/170)]

etherscan/etherscan.go

@@ -148,6 +148,20 @@ func (e *Etherscan) GetContractCode(addr ethgo.Address) (*ContractCode, error) {
 	return out[0], nil
 }
 
+func (e *Etherscan) GasPrice() (uint64, error) {
+	var out struct {
+		LastBlock string `json:"LastBlock"`
+	}
+	if err := e.Query("gastracker", "gasoracle", &out, map[string]string{}); err != nil {
+		return 0, err
+	}
+	num, err := strconv.Atoi(out.LastBlock)
+	if err != nil {
+		return 0, err
+	}
+	return uint64(num), nil
+}
+
 func (e *Etherscan) GetLogs(filter *ethgo.LogFilter) ([]*ethgo.Log, error) {
 	if len(filter.Address) == 0 {
 		return nil, fmt.Errorf("an address to filter is required")

etherscan/etherscan_test.go

@@ -56,3 +56,11 @@ func TestGetLogs(t *testing.T) {
 	assert.NoError(t, err)
 	assert.NotEmpty(t, logs)
 }
+
+func TestGasPrice(t *testing.T) {
+	e := testEtherscanMainnet(t)
+
+	gas, err := e.GasPrice()
+	assert.NoError(t, err)
+	assert.NotZero(t, gas)
+}

website/pages/integrations/etherscan.mdx

@@ -94,3 +94,11 @@ Input:
 Output:
 
 - `logs` <Log text="[]Log"/>: List of logs that match the filter.
+
+## GasPrice
+
+<GoDocLink href="etherscan#Etherscan.GasPrice">GasPrice</GoDocLink> returns the gas price of the latest block.
+
+Output:
+
+- `gasPrice` (`uint64`): Gas price of the latest block.