This project was bootstrapped with Create React App.

ScanAndGo Development Project

Open-source 2020 Google Internship project. ScanAndGo is a Spot-as-a-service app within the larger Google Pay app that allows for users to scan barcodes within registered stores for quick checkout without queuing. View the webapp.

Development

Prerequisites

1. Node js v10 or recommended with a node version manager nvm
2. Npm with node or install Yarn

First-time set-up

1. cd /client
2. Install project dependencies by running yarn install .
3. Obtain keys for required environment variables specified in /client/env_template and /server/env_template and store it in .env file. This file or any keys should not be checked in.
4. cd /server
5. Install project dependencies by running yarn install .
6. Install git-secrets with GCP support

Front-end Server (React)

Run yarn dev from /client directory. This runs react-scripts start and watches folder for changes, updating automatically.

Back-end Server (Express)

Run yarn dev from /server directory. This runs nodemon server.js --watch controllers/ --watch routers/ which starts the express server while watching for changes in the /server/controllers and /server/routers directory, restarting the server when changes are detected.

Alternatively when developing for front-end, we can just do yarn start & to run the express server in the background.

Development Note: We start the express server on port:3143 and proxy unknown requests received by front-end to this port. See /client/package.json:26 where we configure the proxy for the react front-end to http://127.0.0.1:3143 for local development communication between client and server processes.

AppEngine Deployment

After setup of gcloud-SDK, run gcloud app deploy in subdirectories /client and /server. Note that /client needs to be built first with yarn build

With this, we will deploy client front-end react app to default service and back-end express app to api service. This is configured in app.yaml within /client and /server directories.

Routing (initial setup only)

On project root directory, run gcloud app deploy dispatch.yaml to ensure we re-route all requests to */api/* to our api appengine service which is running our express server.

Testing Framework

Both the /client and /server NodeJS projects are configured to run test suites with Jest.

Server Testing

In addition to Jest, the server requires supertest and @firebase/testing together with an emulated Cloud Firestore running on our local development environment.

The firebase CLI to run our emulator can be easily installed with yarn global add firebase-tools or npm install -g firebase-tools. Afterwhich, we require a valid Java Runtime Environment installed to run the Firebase emulator. It is suggested to install openjdk-11-jdk on linux machines with sudo apt-get install default-jdk.

Finally, we can start our emulator prior to running any tests with:

firebase emulators:start --only firestore

And test with yarn test. In /server/package.json, we define a pretest script to wipe our emulated database before each run of test to ensure we clean.

Server Test Steps:

1. firebase emulators:start --only firestore
2. yarn test
   • Automatically runs yarn pretest first: curl -X DELETE "http://localhost:8080/emulator/v1/projects/scan-and-go-for-gpay/databases/(default)/documents"
   • NODE_ENV=\"test\" jest

Note: Our firestore.js module automatically detects which handle to grab based on the environment variable: NODE_END. When this is "test", we load up the emulatedFirestore.js module rather than use the live Firestore variable (connecting to actual Cloud Firestore DB).