These are the random solution to the issues I have faced while developing the application in front-end and these are my hand tools to fix issues and refer anytime in need. Hope it helps you in your search for solutions. Will keep updating with more and were need of improvement required to this page.

Solution to common issues

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ANGULAR - To use on CLI
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//to run server with proxy file optionally can be set under angular.json > server > options >
ng serve --proxy-config proxy.config.json

//if need to add port optionally
ng serve --proxy-config proxy.config.json --port 9999


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EXPRESS - To use on CLI
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 express --view=pug spar-api

   create : spar-api\
   create : spar-api\public\
   create : spar-api\public\javascripts\
	.
	.

   change directory:
     > cd spar-api

   install dependencies:
     > npm install

   run the app:
     > SET DEBUG=spar-api:* & npm start

On Windows use this command
	set DEBUG=myapp:* & npm start

On Mac or linux
	DEBUG=myapp:* npm start


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TO CREATE SECRECT KEY
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Window terminal side of code: 

node -e "console.log(require('crypto').randomBytes(256).toString('base64')); #not working with jwt token signing trying other way below: 


Source: https://gist.github.com/Holger-Will/3edeea6855f1d69a5368871bce5ea926 

(tried on windows 7, working find with angular-jwt app)

# generate private key
openssl genrsa -out private.pem 2048

# extatract public key from it
openssl rsa -in private.pem -pubout > public.pem


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Express side of code:

//Normalizing the path for windows environment
var normalPKPath = path.normalize( __dirname + '/private.key');

const RSA_PRIVATE_KEY = fs.readFileSync(normalPKPath, 'utf8');


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FIREBASE SETUP FOR ANGULAR CLI PROJECT
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Create project in firebase console web page; https://console.firebase.google.com/

install firebase tool

> npm install -g firebase-tool

> firebase login 

Google will try to login with your google account 

(prior to init everytime, you have to make angular prod build ready and do firebase init each time for new deployment to firebase server)

> firebase init 

couple of questions will be asked after init command, type of deployment for web choose Hosting by presseing space bar key after selecting the option in list.
next publish folder path to be, in angular cli its dist folder for production build, type dist and hit enter 
next it will ask you is your app is singple page app or not? type yes and hit enter
next it will ask do you want to replace existing index.html with firebase choose now? because our prod build as created file under dist folder.
next will create necessary files in your app directoy related to firebase/

make sure you update enviorments.prod.ts with firebase configuration detail, which you will get object from firebase console Create app for web page by clicking on it, 

under project overview page.

next finially execute

firebase deploy 

optionally you may use firebase deploy --proiect <project name> 

if everything fine you will see app running under firebase server


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ZEIT NOW - ISSUE SOLUTION
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Build failing for typescript file: giving error Error: Cannot find module 'typescript'

Fix to use @now/node@0.4.28-canary.6: in now.json file to make a build :
solution source: Github Issue <https://github.com/zeit/now-builders/issues/181>

Example:     { "src": "./src/app/server/*.ts", "use": "@now/node@0.4.28-canary.6"}