Feature/arnav jacob/page footer

backend/src/app.ts

@@ -6,6 +6,7 @@ import "dotenv/config";
 import cors from "cors";
 import express, { NextFunction, Request, Response } from "express";
 import { isHttpError } from "http-errors";
+import subscriberRoutes from "src/routes/subscriber";
 
 const app = express();
 
@@ -23,7 +24,7 @@ app.use(
   }),
 );
 
-// Routes ( e.g. app.use("/api/task", taskRoutes); )
+app.use("/api/subscribers", subscriberRoutes);
 
 /**
  * Error handler; all errors thrown by server are handled here.

backend/src/controllers/subscriber.ts

@@ -0,0 +1,32 @@
+/*
+ * Controller for the newsletter subscriber route, /api/subscribers.
+ * passes error handling off to /src/util/validationErrorParser.ts
+ */
+
+import { RequestHandler } from "express";
+import { validationResult } from "express-validator";
+import Subscriber from "src/models/subscriber";
+import validationErrorParser from "src/util/validationErrorParser";
+
+export const createSubscriber: RequestHandler = async (req, res, next) => {
+  const errors = validationResult(req);
+  const { email } = req.body;
+
+  try {
+    // validationErrorParser is a helper that throws 400 if there are errors
+    validationErrorParser(errors);
+    const subscriber = await Subscriber.create({
+      email: email,
+    });
+
+    /*
+     * TODO: Handle adding the newsletter subscriber
+     * to a mailing list or however this will be handled.
+     */
+
+    // successfully created subscriber in db
+    res.status(201).json(subscriber);
+  } catch (error) {
+    next(error);
+  }
+};

backend/src/models/subscriber.ts

@@ -0,0 +1,13 @@
+/*
+ * Defines the schema for a newsletter subscriber
+ */
+
+import { InferSchemaType, Schema, model } from "mongoose";
+
+const subscriberSchema = new Schema({
+  email: { type: String, required: true },
+});
+
+type Subscriber = InferSchemaType<typeof subscriberSchema>;
+
+export default model<Subscriber>("Subscriber", subscriberSchema);

backend/src/routes/subscriber.ts

@@ -0,0 +1,13 @@
+/*
+ * Newsletter subscription route requests.
+ */
+
+import express from "express";
+import * as SubscriberController from "src/controllers/subscriber";
+import * as SubscriberValidator from "src/validators/subscriber";
+
+const router = express.Router();
+
+router.post("/", SubscriberValidator.createSubscriber, SubscriberController.createSubscriber);
+
+export default router;

backend/src/util/validationErrorParser.ts

@@ -0,0 +1,25 @@
+import { Result, ValidationError } from "express-validator";
+import createHttpError from "http-errors";
+
+/**
+ * Parses through errors thrown by validator (if any exist). Error messages are
+ * added to a string and that string is used as the error message for the HTTP
+ * error.
+ *
+ * @param errors the validation result provided by express validator middleware
+ */
+const validationErrorParser = (errors: Result<ValidationError>) => {
+  if (!errors.isEmpty()) {
+    let errorString = "";
+
+    // parse through errors returned by the validator and append them to the error string
+    for (const error of errors.array()) {
+      errorString += error.msg + " ";
+    }
+
+    // trim removes the trailing space created in the for loop
+    throw createHttpError(400, errorString.trim());
+  }
+};
+
+export default validationErrorParser;

backend/src/validators/subscriber.ts

@@ -0,0 +1,34 @@
+/*
+ * Normalize and validate emails for newsletter subscribers
+ * in the route handler.
+ */
+
+import { body } from "express-validator";
+import Subscriber from "src/models/subscriber";
+
+/*
+ * 1. Trim whitespace then
+ * 2. check if empty then
+ * 3. check if valid email then
+ * 4. normalize email then
+ * 5. check if email already exists in db
+ */
+const makeEmailValidator = () =>
+  body("email")
+    .trim()
+    .exists()
+    .withMessage("email is required")
+    .bail()
+    .isEmail()
+    .withMessage("email must be a valid email address")
+    .bail()
+    .normalizeEmail()
+    .custom(async (value) => {
+      // check if email already exists in db
+      const subscriber = await Subscriber.findOne({ email: value }).exec();
+      if (subscriber !== null) {
+        return Promise.reject(`email is already subscribed`);
+      }
+    });
+
+export const createSubscriber = [makeEmailValidator()];