GraphQL Full-Stack Task

Purpose

• See if a code base can be understood and modified
• See if task descriptions can be understood
• Find out strengths and weaknesses
• Try to tackle every task and find out where you struggled and why
• Be honest to yourself

Backend

The Backend is written in Go and providing a GraphQL API. It uses following technologies:

• gqlgen
• graphql-go-tools

Before starting this task, make sure you get a quick overview of GraphQL: https://graphql.org/learn/.

Currently all tests are failing and the goal will be to make them green again. For this, you will need to follow 3 tasks.

Tests can be run using go test ./... command

You can also start the server manually and send queries to the graphql endpoint:

go run server.go
curl --location --request POST 'localhost:8085/query' --header 'Content-Type: application/json' --data-raw '{"query":"{ heroes { name } }","variables":{}}
curl --location --request POST 'localhost:8085/query' --header 'Content-Type: application/json' --data-raw '{"query":"{ types }","variables":{}}'

Task 1

The heroes query should return a hard-coded slice of Characters. See the test: https://github.com/pvormste/task-gql-full-stack/blob/main/server_test.go#L20

Those are the Characters that should be returned by the server:

[
    {
        "name": "Luke Skywalker",
        "hasLightsaver": true
    },
    {
        "name": "Han Solo",
        "hasLightsaver": false
    },
    {
        "name": "C-3PO",
        "primaryFunction": "Translator"
    }
]   

Hint: Look at the gqlgen documentation to find the right place to add the missing code: https://gqlgen.com/getting-started/#implement-the-resolvers

Task 2

The types query should return only the name of so-called "Object Types" of the GraphQL schema. But there's currently a bug in the code and it is returning also the name of the interface. (See the test: https://github.com/pvormste/task-gql-full-stack/blob/main/server_test.go#L29).

Fix the implementation and make the tests related to this issue pass.

Hint: Look inside the schemaparser package.

Task 3

For the third task you need to extend the GraphQL schema with 2 enums and their values. See the GraphQL documentation on how to add enums to a GraphQL schema: https://graphql.org/learn/schema/#enumeration-types

The schema can be found in graph/schema.graphqls.

First Enum:

• Episode
  • THE_PHANTOM_MENACE
  • ATTACK_OF_THE_CLONES
  • REVENGE_OF_THE_SITHS
  • A_NEW_HOPE
  • THE_EMPIRE_STRIKES_BACK
  • RETURN_OF_THE_JEDI
  • THE_FORCE_AWAKENS
  • THE_LAST_JEDI
  • THE_RISE_OF_SKYWALKER

Second Enum:

• Side
  • JEDI
  • SITH

In the schemaparser package there is a function called CountEnumValues. The test for it is currently failing. Implement the package so that the test turns green again.

How to approach this task:

• The ast.Document type from graphql-go-tools has RootNodes of type ast.Node which are being iterated over in the visitor. See: https://github.com/jensneuse/graphql-go-tools/blob/master/pkg/ast/ast.go#L12
• A ast.Node has a NodeKind and a ref (index) to the specific slice of the NodeKind. See: https://github.com/jensneuse/graphql-go-tools/blob/master/pkg/ast/ast.go#L31
• A EnumTypeDefinition has a EnumValuesDefinitionList See: https://github.com/jensneuse/graphql-go-tools/blob/master/pkg/ast/ast_enum_type_definition.go#L25

Info: Changing the schema only won't change the behavior of the server! But it will be enough to make tests green.

Frontend

The FrontEnd is written in Javascript and uses following technologies:

• React
• Jest

Task 1 (Make all the tests green).

Currently one of the test is failing one FE, make the changes in the appropriate files to make all the test green.

Tests can be run using npm test command

Task 2 (Add UI)

• Use the currently available BE to render a Graphiql playground that helps query the graphql API.

• Modify GraphiQL to add a button that toggles the view of newly added UI.

• Add UI to render the JSON response received from BE.

Wireframe :