unit testing GraphQL in Golang

Question

in this case I am using

• Echo
• mongo-driver (MongoDB)
• gqlgen graphql type safe

is there any simple example for testing my Mutation and Query? I do love to get advices for this. I have tried to find but can't found any so far,

thank you:)

Answer 1

Here is an test example using testify package and the gqlgen/client package which is used internally for testing.

GraphQL schema:

type Query {
  user(loginname: String!): UserDetail
}

type Mutation {
  validateAccessToken(accesstoken: String!): UserEntity
}

type User { 
  loginname: String 
  avatarUrl: String 
}

type UserEntity {
  id: ID!
  loginname: String 
  avatarUrl: String
}

type UserDetail { 
  loginname: String
  avatarUrl: String
  githubUsername: String
  createAt: String
  score: Int
}

graph/resolver/resolver.go :

package resolver

import "github.com/mrdulin/gqlgen-cnode/services"

// This file will not be regenerated automatically.
//
// It serves as dependency injection for your app, add any dependencies you require here.

type Resolver struct {
    UserService    services.UserService
}

services/user.go :

package services

type UserService interface {
    GetUserByLoginname(loginname string) *model.UserDetail
    ValidateAccessToken(accesstoken string) *model.UserEntity
}

graph/resolver/root.resolver.go :

package resolver

// This file will be automatically regenerated based on the schema, any resolver implementations
// will be copied through when generating and any unknown code will be moved to the end.

import (
    "context"

    "github.com/mrdulin/gqlgen-cnode/graph/generated"
    "github.com/mrdulin/gqlgen-cnode/graph/model"
)

func (r *mutationResolver) ValidateAccessToken(ctx context.Context, accesstoken string) (*model.UserEntity, error) {
    return r.UserService.ValidateAccessToken(accesstoken), nil
}

func (r *queryResolver) User(ctx context.Context, loginname string) (*model.UserDetail, error) {
    return r.UserService.GetUserByLoginname(loginname), nil
}

// Mutation returns generated.MutationResolver implementation.
func (r *Resolver) Mutation() generated.MutationResolver { return &mutationResolver{r} }

// Query returns generated.QueryResolver implementation.
func (r *Resolver) Query() generated.QueryResolver { return &queryResolver{r} }

type mutationResolver struct{ *Resolver }
type queryResolver struct{ *Resolver }

Created mock object for UserService :

mocks/userService.go :

package mocks

import (
    "github.com/mrdulin/gqlgen-cnode/graph/model"
    "github.com/stretchr/testify/mock"
)

type MockedUserService struct {
    mock.Mock
}

func (s *MockedUserService) GetUserByLoginname(loginname string) *model.UserDetail {
    args := s.Called(loginname)
    return args.Get(0).(*model.UserDetail)
}

func (s *MockedUserService) ValidateAccessToken(accesstoken string) *model.UserEntity {
    args := s.Called(accesstoken)
    return args.Get(0).(*model.UserEntity)
}

graph/resolver/root.resolver_test.go :

package resolver_test

import (
    "testing"

    "github.com/99designs/gqlgen/client"
    "github.com/99designs/gqlgen/graphql/handler"
    "github.com/mrdulin/gqlgen-cnode/graph/generated"
    "github.com/mrdulin/gqlgen-cnode/graph/model"
    "github.com/mrdulin/gqlgen-cnode/graph/resolver"
    "github.com/mrdulin/gqlgen-cnode/mocks"
    "github.com/stretchr/testify/mock"
    "github.com/stretchr/testify/require"
)

var (
    loginname = "mrdulin"
    avatarURL = "avatar.jpg"
    score     = 50
    createAt  = "1900-01-01"
)

func TestMutationResolver_ValidateAccessToken(t *testing.T) {

    t.Run("should validate accesstoken correctly", func(t *testing.T) {
        testUserService := new(mocks.MockedUserService)
        resolvers := resolver.Resolver{UserService: testUserService}
        c := client.New(handler.NewDefaultServer(generated.NewExecutableSchema(generated.Config{Resolvers: &resolvers})))
        ue := model.UserEntity{ID: "123", User: model.User{Loginname: &loginname, AvatarURL: &avatarURL}}
        testUserService.On("ValidateAccessToken", mock.AnythingOfType("string")).Return(&ue)
        var resp struct {
            ValidateAccessToken struct{ ID, Loginname, AvatarUrl string }
        }
        q := `
      mutation { 
        validateAccessToken(accesstoken: "abc") { 
          id, 
          loginname, 
          avatarUrl 
        } 
      }
    `
        c.MustPost(q, &resp)
        testUserService.AssertExpectations(t)
        require.Equal(t, "123", resp.ValidateAccessToken.ID)
        require.Equal(t, "mrdulin", resp.ValidateAccessToken.Loginname)
        require.Equal(t, "avatar.jpg", resp.ValidateAccessToken.AvatarUrl)
    })

}

func TestQueryResolver_User(t *testing.T) {
    t.Run("should query user correctly", func(t *testing.T) {
        testUserService := new(mocks.MockedUserService)
        resolvers := resolver.Resolver{UserService: testUserService}
        c := client.New(handler.NewDefaultServer(generated.NewExecutableSchema(generated.Config{Resolvers: &resolvers})))
        u := model.UserDetail{User: model.User{Loginname: &loginname, AvatarURL: &avatarURL}, Score: &score, CreateAt: &createAt}
        testUserService.On("GetUserByLoginname", mock.AnythingOfType("string")).Return(&u)
        var resp struct {
            User struct {
                Loginname, AvatarURL, CreateAt string
                Score                          int
            }
        }
        q := `
      query GetUser($loginname: String!) { 
        user(loginname: $loginname) { 
          loginname
          avatarUrl 
          createAt 
          score 
        } 
      }
    `
        c.MustPost(q, &resp, client.Var("loginname", "mrdulin"))
        testUserService.AssertCalled(t, "GetUserByLoginname", "mrdulin")
        require.Equal(t, "mrdulin", resp.User.Loginname)
        require.Equal(t, "avatar.jpg", resp.User.AvatarURL)
        require.Equal(t, 50, resp.User.Score)
        require.Equal(t, "1900-01-01", resp.User.CreateAt)
    })
}

test result:

=== RUN   TestMutationResolver_ValidateAccessToken
=== RUN   TestMutationResolver_ValidateAccessToken/should_validate_accesstoken_correctly
    TestMutationResolver_ValidateAccessToken/should_validate_accesstoken_correctly: root.resolvers_test.go:44: PASS:    ValidateAccessToken(mock.AnythingOfTypeArgument)
--- PASS: TestMutationResolver_ValidateAccessToken (0.00s)
    --- PASS: TestMutationResolver_ValidateAccessToken/should_validate_accesstoken_correctly (0.00s)
=== RUN   TestQueryResolver_User
=== RUN   TestQueryResolver_User/should_query_user_correctly
--- PASS: TestQueryResolver_User (0.00s)
    --- PASS: TestQueryResolver_User/should_query_user_correctly (0.00s)
PASS
ok      github.com/mrdulin/gqlgen-cnode/graph/resolver  0.141s

test coverage report:

source code: https://github.com/mrdulin/gqlgen-cnode