Prototype custom URL shortener sample

Node/custom-url-shortener/.gitignore

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+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+firebase-debug.log*
+firebase-debug.*.log*
+
+# Firebase cache
+.firebase/
+
+# Firebase config
+
+# Uncomment this if you'd like others to create their own Firebase project.
+# For a team working on the same Firebase project(s), it is recommended to leave
+# it commented so all members can deploy to the same project(s) in .firebaserc.
+# .firebaserc
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (http://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env

Node/custom-url-shortener/README.md

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+# Custom shortlinks with Firestore and Firebase Hosting
+
+1. Write a document to the `links` collection in Firestore to create a new shortLink:
+ ```
+ {
+ longUrl: "https://firebase.google.com"
+ }
+ ```
+1. View the available shortlinks at the `/links` path on your Hosting site
+1. Visit a shortlink's path on your hosting site `https://<your-site>/<shortlink>` to be redirected!

Node/custom-url-shortener/firebase.json

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+{
+ "hosting": {
+ "rewrites": [ {
+ "source": "/list",
+ "function": "listAllRedirects"
+ }, {
+ "source": "**",
+ "function": "redirectToFullURL"
+ }]
+ },
+ "functions": [
+ {
+ "source": "functions",
+ "codebase": "default",
+ "ignore": [
+ "node_modules",
+ ".git",
+ "firebase-debug.log",
+ "firebase-debug.*.log"
+ ]
+ }
+ ],
+ "firestore": {
+ "rules": "firestore.rules",
+ "indexes": "firestore.indexes.json"
+ },
+ "emulators": {
+ "functions": {
+ "port": 5001
+ },
+ "firestore": {
+ "port": 8080
+ },
+ "hosting": {
+ "port": 5000
+ },
+ "ui": {
+ "enabled": true
+ },
+ "singleProjectMode": true
+ }
+}

Node/custom-url-shortener/firestore.indexes.json

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+{
+ "indexes": [],
+ "fieldOverrides": []
+}

Node/custom-url-shortener/firestore.rules

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+rules_version = '2';
+service cloud.firestore {
+ match /databases/{database}/documents { 
+ match /links/{linkId} {
+ allow write: if request.auth != null;
+ }
+ }
+}

Node/custom-url-shortener/functions/.gitignore

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+node_modules/

Node/custom-url-shortener/functions/index.js

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+const { onRequest } = require("firebase-functions/v2/https");
+const logger = require("firebase-functions/logger");
+const { onDocumentCreated } = require("firebase-functions/v2/firestore");
+
+const { initializeApp } = require("firebase-admin/app");
+const { getFirestore } = require("firebase-admin/firestore");
+
+initializeApp();
+
+exports.listAllRedirects = onRequest(async (request, response) => {
+ result = await getFirestore().collection("links").get();
+
+ response.type("json");
+ response.send(
+ JSON.stringify(
+ result.docs.map((docSnap) => docSnap.data()),
+ null,
+ 2
+ )
+ );
+});
+
+exports.redirectToFullURL = onRequest(async (request, response) => {
+ const shortLink = request.path.split("/")[1];
+
+ if (!shortLink) {
+ response.status(404).send(`Invalid shortlink "${request.path}"`);
+ logger.info(`Invalid shortlink "${request.path}"`);
+ return;
+ }
+
+ const result = await getFirestore()
+ .collection("links")
+ .where("shortUrl", "==", request.path.split("/")[1])
+ .get();
+
+ if (result.docs.length === 0) {
+ response.status(404).send(`No entry found for shortlink "${shortLink}"`);
+ logger.info(`No entry found for shortlink "${shortLink}"`);
+ return;
+ } else if (result.docs.length > 1) {
+ response.status(500).send(
+ `Found too many URLs. Something is wrong`,
+ result.docs.map((docSnap) => docSnap.ref.id)
+ );
+ return;
+ }
+ const redirectUrl = result.docs[0].data().longUrl;
+
+ logger.info("redirect");
+ response.redirect(301, redirectUrl);
+});
+
+exports.shortenUrl = onDocumentCreated(
+ "links/{linkid}",
+ async (event, params) => {
+ const hash = (Math.random() + 1).toString(36).substring(7);
+
+ // check if the URL is valid
+ try {
+ new URL(event.data.data().longUrl);
+ } catch {
+ logger.error(
+ `invalid URL "${event.data.data().longUrl}"`,
+ event.data.data()
+ );
+ return;
+ }
+
+ await event.data.ref.update({ shortUrl: hash });
+ logger.info(`created shortlink`, {
+ documentId: params.linkid,
+ longUrl: event.data.data().longUrl,
+ shortLink: hash,
+ });
+ }
+);

Node/custom-url-shortener/functions/package.json

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+{
+ "name": "functions",
+ "description": "Cloud Functions for Firebase",
+ "scripts": {
+ "serve": "firebase emulators:start --only functions",
+ "shell": "firebase functions:shell",
+ "start": "npm run shell",
+ "deploy": "firebase deploy --only functions",
+ "logs": "firebase functions:log"
+ },
+ "engines": {
+ "node": "18"
+ },
+ "main": "index.js",
+ "dependencies": {
+ "firebase-admin": "^11.8.0",
+ "firebase-functions": "^4.3.1"
+ },
+ "devDependencies": {
+ "firebase-functions-test": "^3.1.0"
+ },
+ "private": true
+}