feat: add env-script

README.md

@@ -12,6 +12,14 @@ From root directory:
 yarn install
 ```
 
+## Environment Setup
+
+To simplify providing environment variables across all tutorials, a helper script automates creating `.env` files from each existing `.env-sample`.
+
+```bash
+yarn setup-envs
+```
+
 ## Testing
 
 1. Start the nitro-testnode (you can find instructions [here](https://docs.arbitrum.io/run-arbitrum-node/run-local-full-chain-simulation)) with the following parameters:
@@ -26,6 +34,10 @@ yarn install
 yarn run testAll
 ```
 
+### Notes on RPCs and Finality
+
+Using public testnet RPCs can be slow because many tutorials wait for transaction finality or multiple confirmations. Some tests may take 10–15 minutes to complete on testnets. For faster and more reliable execution, prefer running a local node and pointing your environment variables (`CHAIN_RPC`, `PARENT_CHAIN_RPC`, and `L1_RPC` when applicable) to local RPC endpoints.
+
 ## What's included?
 
 #### :white_check_mark: Basics

package.json

@@ -14,7 +14,8 @@
     "lint": "eslint .",
     "prettier:format": "prettier './**/*.{js,json,md,sol,ts,yml}' --write && yarn run lint --fix",
     "prettier:check": "prettier './**/*.{js,json,md,sol,ts,yml}' --check && yarn run lint",
-    "testAll": "tests/runAll.sh"
+    "testAll": "tests/runAll.sh",
+    "setup-envs": "node scripts/setup-envs.js"
   },
   "devDependencies": {
     "@offchainlabs/eslint-config-typescript": "^0.2.1",

scripts/setup-envs.js

@@ -0,0 +1,155 @@
+#!/usr/bin/env node
+
+/*
+ * Environment setup script for Arbitrum Tutorials.
+ * Usage:
+ *   yarn setup-envs
+ */
+
+/* eslint-disable no-await-in-loop */
+
+const fs = require('fs');
+const path = require('path');
+const readline = require('readline');
+
+const VARS = ['PRIVATE_KEY', 'CHAIN_RPC', 'PARENT_CHAIN_RPC', 'L1_RPC'];
+
+function log(msg) {
+  console.log(msg);
+}
+function warn(msg) {
+  console.warn(msg);
+}
+function error(msg) {
+  console.error(msg);
+}
+
+async function promptForValues() {
+  const values = {};
+  const rl = readline.createInterface({ input: process.stdin, output: process.stdout });
+  const ask = (q) => new Promise((res) => rl.question(q, (ans) => res(ans.trim())));
+  for (const v of VARS) {
+    const optional = v === 'L1_RPC';
+    const existing = process.env[v] ? ` [default: ${process.env[v]}]` : '';
+    const prompt = optional ? `${v} (optional)${existing}: ` : `${v}${existing}: `;
+    const ans = await ask(prompt);
+    if (ans) {
+      values[v] = ans;
+    } else if (process.env[v]) {
+      values[v] = process.env[v];
+    } else if (!optional) {
+      error(`Required value missing: ${v}`);
+      process.exit(1);
+    }
+  }
+  rl.close();
+  return values;
+}
+
+function replaceOrAppend(contentLines, key, value) {
+  const prefix = key + '=';
+  let replaced = false;
+  for (let i = 0; i < contentLines.length; i++) {
+    const line = contentLines[i];
+    if (line.startsWith(prefix)) {
+      contentLines[i] = `${key}="${value}"`;
+      replaced = true;
+      break;
+    }
+  }
+  if (!replaced) contentLines.push(`${key}="${value}"`);
+}
+
+function processSampleFile(samplePath, envPath, values) {
+  const lines = fs.readFileSync(samplePath, 'utf8').split(/\r?\n/);
+  while (lines.length && lines[lines.length - 1].trim() === '') lines.pop();
+  for (const v of VARS) {
+    if (values[v]) replaceOrAppend(lines, v, values[v]);
+  }
+
+  const newContent = lines.join('\n') + '\n';
+  fs.writeFileSync(envPath, newContent, 'utf8');
+  if (samplePath !== envPath) {
+    fs.unlinkSync(samplePath); // remove sample after successful creation
+  }
+}
+
+function processDirectory(dir, values, summary) {
+  const samplePath = path.join(dir, '.env-sample');
+  const envPath = path.join(dir, '.env');
+  const hasSample = fs.existsSync(samplePath);
+  const hasEnv = fs.existsSync(envPath);
+
+  if (!hasSample && !hasEnv) return;
+
+  try {
+    if (hasSample) {
+      processSampleFile(samplePath, envPath, values);
+      summary.updated.push(dir);
+    } else if (hasEnv) {
+      processSampleFile(envPath, envPath, values);
+      summary.updated.push(dir);
+    }
+  } catch (e) {
+    summary.errors.push({ dir, error: e.message });
+  }
+}
+
+function validate(values) {
+  const pk = values.PRIVATE_KEY;
+  if (!/^0x[a-fA-F0-9]{64}$/.test(pk)) {
+    throw new Error('PRIVATE_KEY must be 0x + 64 hex characters.');
+  }
+  ['CHAIN_RPC', 'PARENT_CHAIN_RPC'].forEach((k) => {
+    if (!/^https?:\/\/\\S+$/i.test(values[k])) {
+      throw new Error(`${k} must be an http(s) URL.`);
+    }
+  });
+  if (values.L1_RPC && !/^https?:\/\/\\S+$/i.test(values.L1_RPC)) {
+    throw new Error('L1_RPC must be an http(s) URL if provided.');
+  }
+}
+
+async function main() {
+  log('Arbitrum Tutorials environment setup starting...');
+  const values = await promptForValues();
+
+  if (!values.PRIVATE_KEY || !values.CHAIN_RPC || !values.PARENT_CHAIN_RPC) {
+    error('PRIVATE_KEY, CHAIN_RPC, and PARENT_CHAIN_RPC are required.');
+    process.exit(1);
+  }
+
+  validate(values);
+
+  const rootDir = path.resolve(__dirname, '..');
+  const packagesDir = path.join(rootDir, 'packages');
+
+  const summary = { updated: [], errors: [] };
+
+  processDirectory(rootDir, values, summary);
+
+  if (fs.existsSync(packagesDir)) {
+    const entries = fs.readdirSync(packagesDir);
+    for (const entry of entries) {
+      const fullPath = path.join(packagesDir, entry);
+      if (fs.statSync(fullPath).isDirectory()) {
+        processDirectory(fullPath, values, summary);
+      }
+    }
+  }
+
+  log('Environment setup complete.');
+  log(`Updated: ${summary.updated.length}`);
+  if (summary.errors.length) {
+    warn('Errors encountered:');
+    for (const e of summary.errors) warn(` - ${e.dir}: ${e.error}`);
+  }
+
+  log('\nExample: run a tutorial script after env creation:');
+  log('  cd packages/greeter && npx hardhat run scripts/sendParentMessage.ts');
+}
+
+main().catch((e) => {
+  error(e.stack || e.message);
+  process.exit(1);
+});