Fix race condition on proxy server (#374)

* [skip testnet]

---------

Co-authored-by: FabijanC <fabijan.corak@gmail.com>

package.json

@@ -37,6 +37,7 @@
     "dependencies": {
         "@nomiclabs/hardhat-docker": "^2.0.2",
         "axios": "^1.0.0",
+        "axios-retry": "^3.5.0",
         "exit-hook": "2.2.1",
         "form-data": "^4.0.0",
         "glob": "^10.0.0",

src/external-server/external-server.ts

@@ -5,6 +5,7 @@ import { StarknetPluginError } from "../starknet-plugin-error";
 import { IntegratedDevnetLogger } from "./integrated-devnet-logger";
 import { StringMap } from "../types";
 import { HardhatRuntimeEnvironment } from "hardhat/types";
+import axiosRetry from "axios-retry";
 
 function sleep(amountMillis: number): Promise<void> {
     return new Promise((resolve) => {
@@ -46,6 +47,7 @@ export async function getFreePort(): Promise<string> {
 export abstract class ExternalServer {
     protected childProcess: ChildProcess;
     private connected = false;
+    private connecting = false; // Flag indicating whether the proxy server is currently in the process of connecting
     private lastError: string = null;
     private _isDockerDesktop: boolean = null;
 
@@ -177,8 +179,11 @@ export abstract class ExternalServer {
     }
 
     public async post<T>(data: StringMap): Promise<T> {
+        await this.ensurePort();
         await this.ensureStarted();
 
+        // The default value of retries, which is 3, does not work on CircleCI
+        axiosRetry(axios, { retries: 5, retryDelay: axiosRetry.exponentialDelay });
         const hre: HardhatRuntimeEnvironment = await import("hardhat");
 
         try {
@@ -193,10 +198,19 @@ export abstract class ExternalServer {
         }
     }
 
+    private async ensurePort(): Promise<void> {
+        if (this.port) {
+            return;
+        }
+        this.port = await getFreePort();
+    }
+
     private async ensureStarted(): Promise<void> {
-        if (this.connected) {
+        if (this.connected || this.connecting) {
             return;
         }
+        this.connecting = true;
         await this.start();
+        this.connecting = false;
     }
 }

src/starknet-venv-proxy.ts

@@ -1,6 +1,5 @@
 import { ChildProcess, spawn } from "child_process";
 import { ExternalServer } from "./external-server";
-import { getFreePort } from "./external-server/external-server";
 
 import path from "path";
 
@@ -10,7 +9,6 @@ export class StarknetVenvProxy extends ExternalServer {
     }
 
     protected async spawnChildProcess(): Promise<ChildProcess> {
-        this.port = await getFreePort();
         const proxyServerPath = path.join(__dirname, "starknet_cli_wrapper.py");
         return spawn(this.pythonPath, [proxyServerPath, this.port]);
     }

test/integrated-devnet-tests/predeployed-accounts-test/check.ts

@@ -0,0 +1,12 @@
+import { hardhatStarknetTest } from "../../utils/cli-functions";
+import { checkDevnetIsNotRunning } from "../../utils/utils";
+
+// Tests race condition on proxy server by making multiple calls to the
+// function getAccountFromAddress and that the proxy server
+// handles simultaneous requests correctly and that the port assignment
+// on the integrated-devnet environment is implemented correctly
+(async () => {
+    await checkDevnetIsNotRunning();
+    hardhatStarknetTest("--no-compile test/get-predeployed-accounts.test.ts".split(" "));
+    await checkDevnetIsNotRunning();
+})();

test/integrated-devnet-tests/predeployed-accounts-test/hardhat.config.ts

@@ -0,0 +1,13 @@
+import "@shardlabs/starknet-hardhat-plugin";
+
+module.exports = {
+    starknet: {
+        network: process.env.NETWORK
+    },
+    networks: {
+        integratedDevnet: {
+            venv: "active",
+            url: "http://127.0.0.1:5050"
+        }
+    }
+};

test/integrated-devnet-tests/predeployed-accounts-test/network.json

@@ -0,0 +1,4 @@
+{
+    "$schema": "../../network.schema",
+    "integrated-devnet": true
+}