Dojo: Introduction to GraphQL

This repository contains some GraphQL code that covers its usage on Back-End (plus GraphiQL). Presentation Link.

Pre-reqs

• npm
• node

# My current environment

$ npm -v
6.4.1

$ node -v
v10.14.1

Hands-on 1/3: My first GraphQL Schema

Go to branch develop/1.

This is your data:

const candidate = {
  id:         string | number,
  name:       string,
  email:      string,
  profession: 'frontend' | 'backend' | 'devops' | 'ux' | 'po' | 'tester',
  photo:      string,
  following:  array of candidate ID,
};

const company = {
  id:         string | number,
  name:       string,
  photo:      string,
  openJobAds: array of jobAd IDs,
};

const jobAd = {
  id:                 string | number,
  title:              string,
  description:        string,  // Optional
  forCompany:         company ID,
  requiredProfession: 'frontend' | 'backend' | 'devops' | 'ux' | 'po' | 'tester',
  remainingVacancies:  number,
};

You may check data-sources/ folder for more details about how is your data.

Your first step is to build your GraphQL schema at schema.graphql file!

Reference:

• https://graphql.org/learn/schema/

You can test it with:

$ npm install
$ npm run lint:graphql

Solution on branch solution/1.

Hands-on 2/3: My first Resolver

Go to branch develop/2.

Resolvers are functions that tell GraphQL how to provide your data.

• You need 1 resolver for each query
• You need 1 resolver for each field of a type you defined in your schema.graphql

Now, you want to enable 3 queries for your users:

• candidates
• companies
• jobAds

For that, implement those basic resolvers at resolvers/ folder, using the imported functions from your services/ folder.

You can test your resolvers with:

$ npm start               # Manually at http://localhost:3000/graphql
$ npm run test:graphql    # Automatically

Reference:

• https://graphql.org/learn/execution/
• https://graphql.org/graphql-js/basic-types/

Solution on branch solution/2.

Hands-on 3/3: Passing parameters to Resolvers

Go to branch develop/3.

Implement 3 new queries for your users:

• One that retrieves data from a candidate, either by id or email
• One that retrieves data from a company, given its id
• One that retrieves data from a jobAd, given its id

Again: check your services/ to reuse you already existing code!
More automated tests were added, so feel free to run the same scripts :)

Reference:

• https://graphql.org/graphql-js/passing-arguments/
• https://graphql.org/graphql-js/object-types/

Solution on branch solution/3.