docs(examples): Add Node.js express server validate email example (#343)

* docs(examples): Added Node.js express server validate email example

* Fix email

* Remove body parser as its built in

* Add dependabot config

* Update examples/nodejs-express-validate-email/index.js

---------

Co-authored-by: blaine-arcjet <[email protected]>

.github/dependabot.yml

@@ -237,6 +237,23 @@ updates:
         patterns:
           - "*"
 
+  - package-ecosystem: npm
+    directory: /examples/nodejs-express-validate-email
+    schedule:
+      # Our dependencies should be checked daily
+      interval: daily
+    assignees:
+      - blaine-arcjet
+    reviewers:
+      - blaine-arcjet
+    commit-message:
+      prefix: deps(example)
+      prefix-development: deps(example)
+    groups:
+      dependencies:
+        patterns:
+          - "*"
+
   - package-ecosystem: npm
     directory: /examples/nodejs-rl
     schedule:

examples/nodejs-express-rl/README.md

@@ -21,7 +21,7 @@ This example shows how to use Arcjet with a Node.js
 2. Enter this directory and install the example's dependencies.
 
    ```bash
-   cd examples/nodejs-express
+   cd examples/nodejs-express-rl
    npm ci
    ```
 

examples/nodejs-express-validate-email/.env.local.example

@@ -0,0 +1 @@
+ARCJET_KEY=

examples/nodejs-express-validate-email/README.md

@@ -0,0 +1,47 @@
+<a href="https://arcjet.com" target="_arcjet-home">
+  <picture>
+    <source media="(prefers-color-scheme: dark)" srcset="https://arcjet.com/arcjet-logo-minimal-dark-mark-all.svg">
+    <img src="https://arcjet.com/arcjet-logo-minimal-light-mark-all.svg" alt="Arcjet Logo" height="128" width="auto">
+  </picture>
+</a>
+
+# Arcjet email verification with Express for Node.js
+
+This example shows how to use Arcjet with a Node.js
+[Express](https://expressjs.com/) server.
+
+## How to use
+
+1. From the root of the project, install the SDK dependencies.
+
+   ```bash
+   npm ci
+   ```
+
+2. Enter this directory and install the example's dependencies.
+
+   ```bash
+   cd examples/nodejs-express-validate-email
+   npm ci
+   ```
+
+3. Rename `.env.local.example` to `.env.local` and add your Arcjet key.
+
+4. Start the server.
+
+   ```bash
+   npm start
+   ```
+
+   This assumes you're using Node.js 20 or later because the `start` script
+   loads a local environment file with `--env-file`. If you're using an older
+   version of Node.js, you can use a package like
+   [dotenv](https://www.npmjs.com/package/dotenv) to load the environment file.
+
+5. Execute a curl request with an invalid email e.g.
+
+   ```bash
+   curl -X POST -d '[email protected]' http://localhost:3000/
+   ```
+
+6. The request will be blocked and the server logs will show the details.

examples/nodejs-express-validate-email/index.js

@@ -0,0 +1,40 @@
+import arcjet, { validateEmail } from "@arcjet/node";
+import express from "express";
+
+const app = express();
+const port = 3000;
+
+app.use(express.urlencoded({ extended: false }));
+
+const aj = arcjet({
+  // Get your site key from https://app.arcjet.com and set it as an environment
+  // variable rather than hard coding.
+  key: process.env.ARCJET_KEY,
+  rules: [
+    validateEmail({
+      mode: "LIVE", // will block requests. Use "DRY_RUN" to log only
+      block: ["NO_MX_RECORDS"], // block email addresses with no MX records
+    }),
+  ],
+});
+
+app.post('/', async (req, res) => {
+  console.log("Email received: ", req.body.email)
+
+  const decision = await aj.protect(req, {
+    email: req.body.email,
+  });
+  console.log("Arcjet decision", decision);
+
+  if (decision.isDenied()) {
+    res.writeHead(403, { "Content-Type": "application/json" });
+    res.end(JSON.stringify({ error: "Forbidden" }));
+  } else {
+    res.writeHead(200, { "Content-Type": "application/json" });
+    res.end(JSON.stringify({ message: "Hello World", email: req.body.email }));
+  }
+})
+
+app.listen(port, () => {
+  console.log(`Example app listening on port ${port}`)
+})