Merge pull request #16 from getsafle/feature-calculate-tx-fees

Function to get the tx fees

Author: apoorvq

.gitignore

@@ -1 +1,3 @@
-node_modules
+node_modules
+.vscode
+test.js

CHANGELOG.md

@@ -39,3 +39,9 @@
 ##### Implement transaction broadcast functionality
 
 - Added `sendTransaction()` function to send a signed transaction to the blockchain.
+
+### 1.4.0 (2022-04-12)
+
+##### Function to get the transaction fees
+
+- Added `getFees()` function to get the transaction fees for a raw transaction object.

README.md

@@ -84,3 +84,9 @@ const balance = await getBalance(address, web3);
 ```
 const receipt = await ethController.sendTransaction(signedTx, web3);
 ```
+
+### Calculate Tx Fees
+
+```
+const fees = await ethController.getFees(rawTx, web3);
+```

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@getsafle/vault-eth-controller",
-  "version": "1.3.0",
+  "version": "1.4.0",
   "description": "Ethereum controller for safle vault.",
   "main": "src/index.js",
   "scripts": {

package.json

@@ -532,6 +532,19 @@ class KeyringController extends EventEmitter {
     const receipt = await web3.eth.sendSignedTransaction(signedTx);
     return { transactionDetails: receipt.transactionHash }
   }
+
+  async getFees(rawTx, web3) {
+    const { from, to, value, data, gasLimit, maxFeePerGas } = rawTx
+    const estimate = gasLimit ? gasLimit : await web3.eth.estimateGas({ to, from, value, data });
+
+    const re = /[0-9A-Fa-f]{6}/g;
+
+    const maxFee = (re.test(maxFeePerGas)) ? parseInt(maxFeePerGas, 16) : maxFeePerGas;
+
+    const gas = (re.test(estimate)) ? parseInt(estimate, 16) : estimate
+    
+    return { transactionFees: web3.utils.fromWei((gas * maxFee).toString(), 'ether') }
+  }
 }
 
 const getBalance = async (address, web3) => {