Add estimate message fee

scripts/test.sh

@@ -9,7 +9,7 @@ CONFIG_FILE_NAME="hardhat.config.ts"
 
 # setup example repo
 rm -rf starknet-hardhat-example
-EXAMPLE_REPO_BRANCH="plugin"
+EXAMPLE_REPO_BRANCH="estimate-message-fee"
 if [[ "$CIRCLE_BRANCH" == "master" ]] && [[ "$EXAMPLE_REPO_BRANCH" != "plugin" ]]; then
     echo "Invalid example repo branch: $EXAMPLE_REPO_BRANCH"
     exit 1

src/devnet-utils.ts

@@ -3,10 +3,11 @@ import axios, { AxiosResponse, Method } from "axios";
 import { StarknetPluginError } from "./starknet-plugin-error";
 import { Devnet, HardhatRuntimeEnvironment } from "hardhat/types";
 
-import { Block, MintResponse, L2ToL1Message } from "./starknet-types";
+import { Block, MintResponse, L2ToL1Message, FeeEstimation } from "./starknet-types";
 import { REQUEST_TIMEOUT } from "./constants";
 import { hash } from "starknet";
 import { numericToHexString } from "./utils";
+import { hexToDecimalString } from "starknet/utils/number";
 
 interface L1ToL2Message {
     address: string;
@@ -117,6 +118,34 @@ Make sure you really want to interact with Devnet and that it is running and ava
         return response.data;
     }
 
+    public async estimateMessageFee(
+        fromAddress: string,
+        toAddress: string,
+        funcionName: string,
+        payload: number[]
+    ) {
+        const body = {
+            from_address: hexToDecimalString(fromAddress),
+            to_address: toAddress,
+            entry_point_selector: hash.getSelectorFromName(funcionName),
+            payload: payload.map((item) => numericToHexString(item))
+        };
+
+        const response = await this.requestHandler<FeeEstimation>(
+            "/feeder_gateway/estimate_message_fee",
+            "POST",
+            body
+        );
+
+        const { gas_price, gas_usage, overall_fee, unit } = response.data;
+        return {
+            amount: BigInt(overall_fee),
+            unit,
+            gas_price: BigInt(gas_price),
+            gas_usage: BigInt(gas_usage)
+        };
+    }
+
     public async loadL1MessagingContract(networkUrl: string, address?: string, networkId?: string) {
         const body = {
             networkId,

src/types/devnet.ts

@@ -7,7 +7,7 @@ import {
     L1ToL2MockTxResponse,
     L2ToL1MockTxResponse
 } from "../devnet-utils";
-import { Block, MintResponse } from "../starknet-types";
+import { Block, FeeEstimation, MintResponse } from "../starknet-types";
 
 export interface Devnet {
     /**
@@ -23,6 +23,21 @@ export interface Devnet {
      */
     flush: () => Promise<FlushResponse>;
 
+    /**
+     * Computes message fee estimation
+     * @param {string} fromAddress - Address of message source
+     * @param {string} toAddress - Address of message destination
+     * @param {string} functionName - Function name for entry point selector
+     * @param {Array<number>} payload - Payload to send
+     * @returns Fee estimation
+     */
+    estimateMessageFee: (
+        fromAddress: string,
+        toAddress: string,
+        funcionName: string,
+        payload: Array<number>
+    ) => Promise<FeeEstimation>;
+
     /**
      * Deploys or loads the L1 messaging contract.
      * @param {string} networkUrl - L1 network url.

www/docs/intro.md

@@ -287,6 +287,14 @@ it("should estimate fee", async function () {
 
     const invokeFee = await account.estimateFee(contract, "method", { arg1: 10n });
     await account.invoke(contract, "method", { arg1: 10n }); // computes max fee implicitly
+
+    // computes message estimate fee
+    const estimatedMessageFee = await starknet.devnet.estimateMessageFee(
+            L1_CONTRACT_ADDRESS,
+            l2contract.address,
+            "deposit",
+            [556, 123]
+        );
 });
 ```