Set up Angular locally

npx @angular/cli@17 new front-end --no-standalone

cd front-end

ng serve --open --configuration development

old commands:

ng serve --proxy-config proxy.conf.json

npm start

http://localhost:4200/

Set up nest server locally

nest new nest-proxy

cd nest-proxy

npm run start

http://localhost:3000/

Enable Hot Reloading (Optional)

npm run start:dev

Test the API

Test in ThunderClient or POSTMAN

Connect to MongoDB ,install Mongoose:

npm install @nestjs/mongoose mongoose

Flow Overview

User submits a form in your Angular frontend (e.g., name, email, password).

Angular sends the data to the NestJS backend via an API (POST /users).

NestJS processes the request and stores the user in MongoDB.

MongoDB stores the user in a users collection.

NestJS returns a response to Angular, confirming the user was created.

CORS is enabled (app.enableCors()) in nestjs main.ts as 4200 port is calling 3000 port to connect to mongodb

fully switch to Jest for unit testing

uninstall jasmine-karma

npm uninstall karma karma-chrome-launcher karma-coverage karma-jasmine karma-jasmine-html-reporter

then install Jest

npm install --save-dev jest jest-preset-angular @testing-library/angular @types/jest

npm install --save-dev @types/jest

npm install --save-dev @testing-library/jest-dom

run:

npm test

snapshot testing in jest (snapshots) within the component folder itself

Remove all packages of jasmine karma before executing jest: npx jest

"@types/jasmine": "~5.1.0",

"jasmine-core": "~5.1.0",

Jest snapshot testing

✅ Avoids conflicts – No mixing of render and TestBed.

✅ Uses TestBed for all tests – Consistent setup for regular and snapshot tests.

✅ Manually extracts HTML – Ensures snapshot testing without unnecessary test environments.