To build a example chat app.

* make sure you have installed Angular CLI

* add environment variable mongodb_gdg for your MongoDb, the gdg_test database will be used.
export mongodb_gdg='<<USERNAME>>:<<PASSWORD>>@<<MONGODB_URL>>'

Start:

npm i;
cd web;
npm i;
npm i -g @angular/cli;
ng build --prod && 
cd .. && 
tsc &&
npm run serve;

goto http://localhost:3000

start a mongodb atlas server

Start from scratch

npm init;
npm install express mongoose apollo-server-express graphql class-validator type-graphql reflect-metadata @typegoose/typegoose body-parser
 --save;
npm install @types/express @types/mongoose @types/body-parser --save-dev;

typescript config file.

{
	"compilerOptions": {
		"outDir": "./build",
		"rootDir": ".",
		"experimentalDecorators": true,
    	"emitDecoratorMetadata": true,
		"strictPropertyInitialization": false,
	},
	"exclude": [
		"web/**/*",
	]
}

mkdir web;
cd web;
ng new ui --directory ./;
ng serve;

angular.json

{
	"projects": {
		"ui": {
			"architect": {
				"build": {
					"options": {
						"outputPath": "dist/dev"
					},
					"configurations": {
						"production": {
							"outputPath": "dist/production"
						}
					}
				}
			}
		}
	}
}

web/package.json

{
	"scripts": {
		"bp": "ng build --prod --aot --vendor-chunk --common-chunk --buildOptimizer"
	}
}

mkdir schema;
mkdir server;

Adding Apollo to angular

ng add apollo-angular;

A new Angular Module graphql.module.ts file should be automatically created

If you do not get this file please visit: https://www.apollographql.com/docs/angular/basics/setup/#installation-without-angular-schematics

Adding GraphQL Code Generation Tools

npm install --save-dev @graphql-codegen/cli @graphql-codegen/typescript;
npx graphql-codegen init;

1. What type of application are you building? Application built with Angular
2. Where is your schema? http://localhost:3000/graphql
3. Where are your operations and fragments? Enter
4. Pick plugins: Enter
5. Where to write the output: Enter
6. Do you want to generate an introspection file? Enter
7. How to name the config file? Enter
8. What script in package.json should run the codegen? cg
   1. This allow you to use npm run cg; to do code generate from graphql query

npm i;

Create a file with simple query @ src > app > test.graphql

query Test{
	scho
}

Notes:

1. If you need a MongoDb database use MongoDb Atlas its' free.