Allow lib user set buffer for request price to pay and remove hardcoded buffer from EIP-1559 gas pricing (#23)

* allow lib user set buffer for request price to pay

* update tests

Author: najienka

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "randomness-js",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "description": "A library for consuming, verifying and using randomness from the dcipher network",
   "source": "src/index.ts",
   "main": "./dist/cjs/index.cjs",

package.json

@@ -48,6 +48,7 @@ export type RandomnessVerificationConfig = {
 
 type RequestRandomnessParams = {
     callbackGasLimit: bigint
+    bufferPercent: bigint
     timeoutMs: number
     confirmations: number
     pollingIntervalMs: number
@@ -66,6 +67,7 @@ export class Randomness {
         this.contract = RandomnessSender__factory.connect(this.networkConfig.contractAddress, rpc)
         this.defaultRequestParams = {
             callbackGasLimit: networkConfig.callbackGasLimitDefault,
+            bufferPercent: 50n,
             timeoutMs: defaultRequestTimeoutMs,
             confirmations: 1,
             pollingIntervalMs: 500,
@@ -99,7 +101,7 @@ export class Randomness {
         const maxPriorityFeePerGas = feeData.maxPriorityFeePerGas!;
 
         // 2. Use EIP-1559 pricing
-        const txGasPrice = (maxFeePerGas + maxPriorityFeePerGas) * 10n;
+        const txGasPrice = maxFeePerGas + maxPriorityFeePerGas;
 
         // 3. Estimate request price using the selected txGasPrice
         const requestPrice = await this.contract.estimateRequestPriceNative(
@@ -108,7 +110,9 @@ export class Randomness {
         );
 
         // 4. Apply buffer (e.g. 100% = 2× total)
-        const bufferPercent = isFilecoin(Number(chainId)) ? 300n : 50n;
+        const bufferPercent = config.bufferPercent !== undefined
+            ? config.bufferPercent
+            : (isFilecoin(Number(chainId)) ? 300n : 100n);
         const valueToSend = requestPrice + (requestPrice * bufferPercent) / 100n;
 
         // 5. Estimate gas
@@ -191,7 +195,7 @@ export class Randomness {
      * @param callbackGasLimit The callbackGasLimit to use when fulfilling the request with a decryption key.
      * @returns The estimated request price and the transaction gas price used
      */
-    async calculateRequestPriceNative(callbackGasLimit: bigint): Promise<[bigint, bigint]> {
+    async calculateRequestPriceNative(callbackGasLimit: bigint, config: Partial<RequestRandomnessParams> = this.defaultRequestParams): Promise<[bigint, bigint]> {
         if (this.rpc.provider == null) {
             throw Error("RPC requires a provider to request randomness")
         }
@@ -209,7 +213,7 @@ export class Randomness {
         const maxPriorityFeePerGas = feeData.maxPriorityFeePerGas!;
 
         // 2. Use EIP-1559 pricing
-        const txGasPrice = (maxFeePerGas + maxPriorityFeePerGas) * 10n;
+        const txGasPrice = maxFeePerGas + maxPriorityFeePerGas;
 
         // 3. Estimate request price using the selected txGasPrice
         const requestPrice = await this.contract.estimateRequestPriceNative(
@@ -218,7 +222,9 @@ export class Randomness {
         );
 
         // 4. Apply buffer (e.g. 100% = 2× total)
-        const bufferPercent = isFilecoin(Number(chainId)) ? 300n : 100n;
+        const bufferPercent = config.bufferPercent !== undefined
+            ? config.bufferPercent
+            : (isFilecoin(Number(chainId)) ? 300n : 100n);
         const valueToSend = requestPrice + (requestPrice * bufferPercent) / 100n;
 
         return [valueToSend, txGasPrice];

src/index.ts

@@ -47,7 +47,7 @@ describe("randomness", () => {
         const randomness = Randomness.createBaseSepolia(wallet)
         expect(randomness).not.toEqual(null)
 
-        const response = await randomness.requestRandomness({ callbackGasLimit: 100_000n })
+        const response = await randomness.requestRandomness({ callbackGasLimit: 100_000n, bufferPercent: 10n })
         expect(await randomness.verify(response)).toBeTruthy()
 
         rpc.destroy()
@@ -73,7 +73,7 @@ describe("randomness", () => {
         const randomness = Randomness.createPolygonPos(wallet)
         expect(randomness).not.toEqual(null)
 
-        const response = await randomness.requestRandomness({ callbackGasLimit: 100_000n })
+        const response = await randomness.requestRandomness({ callbackGasLimit: 100_000n, bufferPercent: 10n })
         expect(await randomness.verify(response)).toBeTruthy()
 
         rpc.destroy()