graphql-go example integration

Example `graphql-go` integration that is using https://github.com/dariuszkuc/graphql/releases/tag/v0.9.0-federation

NOTE: this is a temporary solution while we are waiting for `graphql-go` PRs to get merged ([651](graphql-go/graphql#651), [652](graphql-go/graphql#652) and [653](graphql-go/graphql#653)).

Resolves: apollographql#74

README.md

@@ -57,6 +57,7 @@ The following open-source GraphQL server libraries and hosted subgraphs provide
 <tr><th width="300">Library</th><th>Federation 1 Support</th><th>Federation 2 Support</th></tr>
 </thead>
 <tbody>
+<tr><td><a href="https://github.com/graphql-go/graphql">GraphQL Go</a></td><td><table><tr><th>_service</th><td>🟢</td></tr><tr><th>@key (single)</th><td>🟢</td></tr><tr><th>@key (multi)</th><td>🟢</td></tr><tr><th>@key (composite)</th><td>🟢</td></tr><tr><th>repeatable @key</th><td>🟢</td></tr><tr><th>@requires</th><td>🟢</td></tr><tr><th>@provides</th><td>🟢</td></tr><tr><th>federated tracing</th><td>🔲</td></tr></table></td><td><table><tr><th>@link</th><td>🟢</td></tr><tr><th>@shareable</th><td>🟢</td></tr><tr><th>@tag</th><td>🟢</td></tr><tr><th>@override</th><td>🟢</td></tr><tr><th>@inaccessible</th><td>🟢</td></tr></table></td></tr>
 <tr><td><a href="https://gqlgen.com">gqlgen</a></td><td><table><tr><th>_service</th><td>🟢</td></tr><tr><th>@key (single)</th><td>🟢</td></tr><tr><th>@key (multi)</th><td>🟢</td></tr><tr><th>@key (composite)</th><td>🟢</td></tr><tr><th>repeatable @key</th><td>🟢</td></tr><tr><th>@requires</th><td>🔲</td></tr><tr><th>@provides</th><td>🟢</td></tr><tr><th>federated tracing</th><td>🟢</td></tr></table></td><td><table><tr><th>@link</th><td>🟢</td></tr><tr><th>@shareable</th><td>🟢</td></tr><tr><th>@tag</th><td>🟢</td></tr><tr><th>@override</th><td>🟢</td></tr><tr><th>@inaccessible</th><td>🟢</td></tr></table></td></tr>
 </tbody>
 </table>

implementations/graphql-go/Dockerfile

@@ -0,0 +1,9 @@
+FROM golang:1.19
+
+WORKDIR /go/src/server
+COPY . .
+
+RUN go get -d -v ./...
+RUN go install -v ./...
+
+CMD go run server.go

implementations/graphql-go/docker-compose.yaml

@@ -0,0 +1,6 @@
+services:
+  products:
+    # must be relative to the root of the project
+    build: implementations/graphql-go
+    ports:
+      - 4001:4001

implementations/graphql-go/go.mod

@@ -0,0 +1,10 @@
+module graphql-go-compatibility
+
+go 1.19
+
+require (
+	github.com/graphql-go/graphql v0.8.0
+	github.com/graphql-go/handler v0.2.3
+)
+
+replace github.com/graphql-go/graphql => github.com/dariuszkuc/graphql v0.9.0-federation

implementations/graphql-go/go.sum

@@ -0,0 +1,4 @@
+github.com/dariuszkuc/graphql v0.9.0-federation h1:dHxP3Z+wX/hRkj/3jaxGXb7iG+Zw3fjW1frQbgsq3lI=
+github.com/dariuszkuc/graphql v0.9.0-federation/go.mod h1:nKiHzRM0qopJEwCITUuIsxk9PlVlwIiiI8pnJEhordQ=
+github.com/graphql-go/handler v0.2.3 h1:CANh8WPnl5M9uA25c2GBhPqJhE53Fg0Iue/fRNla71E=
+github.com/graphql-go/handler v0.2.3/go.mod h1:leLF6RpV5uZMN1CdImAxuiayrYYhOk33bZciaUGaXeU=

implementations/graphql-go/metadata.yaml

@@ -0,0 +1,3 @@
+fullName: GraphQL Go
+language: Go
+documentation: https://github.com/graphql-go/graphql

implementations/graphql-go/model/models.go

@@ -0,0 +1,47 @@
+package model
+
+type User struct {
+	// AverageProductsCreatedPerYear *int    `json:"averageProductsCreatedPerYear"`
+	Email                string  `json:"email"`
+	Name                 *string `json:"name"`
+	TotalProductsCreated *int    `json:"totalProductsCreated"`
+	YearsOfEmployment    int     `json:"yearsOfEmployment"`
+}
+
+type CaseStudy struct {
+	CaseNumber  string  `json:"caseNumber"`
+	Description *string `json:"description"`
+}
+
+type DeprecatedProduct struct {
+	Sku       string  `json:"sku"`
+	Package   string  `json:"package"`
+	Reason    *string `json:"reason"`
+	CreatedBy *User   `json:"createdBy"`
+}
+
+type Product struct {
+	ID         string             `json:"id"`
+	Sku        *string            `json:"sku"`
+	Package    *string            `json:"package"`
+	Variation  *ProductVariation  `json:"variation"`
+	Dimensions *ProductDimension  `json:"dimensions"`
+	CreatedBy  *User              `json:"createdBy"`
+	Notes      *string            `json:"notes"`
+	Research   []*ProductResearch `json:"research"`
+}
+
+type ProductDimension struct {
+	Size   *string  `json:"size"`
+	Weight *float64 `json:"weight"`
+	Unit   *string  `json:"unit"`
+}
+
+type ProductResearch struct {
+	Study   *CaseStudy `json:"study"`
+	Outcome *string    `json:"outcome"`
+}
+
+type ProductVariation struct {
+	ID string `json:"id"`
+}

implementations/graphql-go/products.graphql

@@ -0,0 +1,56 @@
+extend schema
+  @link(
+    url: "https://specs.apollo.dev/federation/v2.0",
+    import: ["@extends", "@external", "@inaccessible", "@key", "@override", "@provides", "@requires", "@shareable", "@tag"]
+  )
+
+type Product @key(fields: "id") @key(fields: "sku package") @key(fields: "sku variation { id }") {
+  id: ID!
+  sku: String
+  package: String
+  variation: ProductVariation
+  dimensions: ProductDimension
+  createdBy: User @provides(fields: "totalProductsCreated")
+  notes: String @tag(name: "internal")
+  research: [ProductResearch!]!
+}
+
+type DeprecatedProduct @key(fields: "sku package") {
+  sku: String!
+  package: String!
+  reason: String
+  createdBy: User
+}
+
+type ProductVariation {
+  id: ID!
+}
+
+type ProductResearch @key(fields: "study { caseNumber }") {
+  study: CaseStudy!
+  outcome: String
+}
+
+type CaseStudy {
+  caseNumber: ID!
+  description: String
+}
+
+type ProductDimension @shareable {
+  size: String
+  weight: Float
+  unit: String @inaccessible
+}
+
+extend type Query {
+  product(id: ID!): Product
+  deprecatedProduct(sku: String!, package: String!): DeprecatedProduct @deprecated(reason: "Use product query instead")
+}
+
+extend type User @key(fields: "email") {
+  averageProductsCreatedPerYear: Int @requires(fields: "totalProductsCreated yearsOfEmployment")
+  email: ID! @external
+  name: String @override(from: "users")
+  totalProductsCreated: Int @external
+  yearsOfEmployment: Int! @external
+}

implementations/graphql-go/resolver/data.go

@@ -0,0 +1,78 @@
+package resolver
+
+import "graphql-go-compatibility/model"
+
+var federationSku = "federation"
+var federationPackage = "@apollo/federation"
+
+var studioSku = "studio"
+
+var productSize = "small"
+var productWeight = 1.0
+var productUnit = "kg"
+
+var products = []*model.Product{
+	{
+		ID:        "apollo-federation",
+		Sku:       &federationSku,
+		Package:   &federationPackage,
+		Variation: &model.ProductVariation{ID: "OSS"},
+		Dimensions: &model.ProductDimension{
+			Size:   &productSize,
+			Weight: &productWeight,
+			Unit:   &productUnit,
+		},
+	},
+	{
+		ID:        "apollo-studio",
+		Sku:       &studioSku,
+		Package:   nil,
+		Variation: &model.ProductVariation{ID: "platform"},
+		Dimensions: &model.ProductDimension{
+			Size:   &productSize,
+			Weight: &productWeight,
+			Unit:   &productUnit,
+		},
+	},
+}
+
+var userName = "Jane Smith"
+var totalProductsCreated = 1337
+
+var users = []*model.User{
+	{
+		Email:                "support@apollographql.com",
+		Name:                 &userName,
+		TotalProductsCreated: &totalProductsCreated,
+	},
+}
+
+var DefaultUser = users[0]
+
+var deprecationReason = "Migrate to Federation V2"
+
+var deprecatedProducts = []*model.DeprecatedProduct{
+	{
+		Sku:     "apollo-federation-v1",
+		Package: "@apollo/federation-v1",
+		Reason:  &deprecationReason,
+	},
+}
+
+var federationStudyDescription = "Federation Study"
+var studioStudyDescription = "Studio Study"
+
+var research = []*model.ProductResearch{
+	{
+		Study: &model.CaseStudy{
+			CaseNumber:  "1234",
+			Description: &federationStudyDescription,
+		},
+	},
+	{
+		Study: &model.CaseStudy{
+			CaseNumber:  "1235",
+			Description: &studioStudyDescription,
+		},
+	},
+}

implementations/graphql-go/resolver/resolvers.go

@@ -0,0 +1,146 @@
+package resolver
+
+import (
+	"math"
+
+	"graphql-go-compatibility/model"
+)
+
+func FindDeprecatedProductBySkuAndPackage(sku string, packageArg string) (*model.DeprecatedProduct, error) {
+	for i := range deprecatedProducts {
+		if deprecatedProducts[i].Sku == sku && deprecatedProducts[i].Package == packageArg {
+			return deprecatedProducts[i], nil
+		}
+	}
+	return nil, nil
+}
+
+func FindProductById(id string) (*model.Product, error) {
+	for i := range products {
+		if products[i].ID == id {
+			return products[i], nil
+		}
+	}
+	return nil, nil
+}
+
+func FindProductBySkuAndPackage(sku string, packageArg string) (*model.Product, error) {
+	for i := range products {
+		if *products[i].Sku == sku && *products[i].Package == packageArg {
+			return products[i], nil
+		}
+	}
+	return nil, nil
+}
+
+func FindProductBySkuAndVariationID(sku string, variationID string) (*model.Product, error) {
+	for i := range products {
+		if *products[i].Sku == sku && products[i].Variation.ID == variationID {
+			return products[i], nil
+		}
+	}
+	return nil, nil
+}
+
+func FindProductResearchByProductId(product *model.Product) ([]*model.ProductResearch, error) {
+	switch product.ID {
+	case "apollo-federation":
+		return research[:1], nil
+	case "apollo-studio":
+		return research[1:], nil
+	default:
+		return nil, nil
+	}
+}
+
+func CalculateAverageProductsCreatedPerYear(user *model.User) (*int, error) {
+	if user.TotalProductsCreated == nil {
+		return nil, nil
+	}
+	var avgProductsCreated = int(math.Round(float64(*user.TotalProductsCreated) / float64(user.YearsOfEmployment)))
+	return &avgProductsCreated, nil
+}
+
+// entity resolvers
+
+// @key(fields: "sku package")
+func DeprecatedProductEntityResolver(params map[string]interface{}) (*model.DeprecatedProduct, error) {
+	sku, skuOk := params["sku"].(string)
+	pkg, pkgOk := params["package"].(string)
+	if skuOk && pkgOk {
+		return FindDeprecatedProductBySkuAndPackage(sku, pkg)
+	}
+	return nil, nil
+}
+
+// @key(fields: "id")
+// @key(fields: "sku package")
+// @key(fields: "sku variation { id }")
+func ProductEntityResolver(params map[string]interface{}) (*model.Product, error) {
+	id, ok := params["id"].(string)
+	if ok {
+		return FindProductById(id)
+	} else {
+		sku, skuOk := params["sku"].(string)
+		if skuOk {
+			pkg, pkgOk := params["package"].(string)
+			if pkgOk {
+				return FindProductBySkuAndPackage(sku, pkg)
+			} else {
+				variation, varOk := params["variation"].(map[string]interface{})
+				if varOk {
+					varId, varIdOk := variation["id"].(string)
+					if varIdOk {
+						return FindProductBySkuAndVariationID(sku, varId)
+					}
+				}
+			}
+		}
+	}
+	return nil, nil
+}
+
+// @key(fields: "study { caseNumber }")
+func ProductResearchEntityResolver(params map[string]interface{}) (*model.ProductResearch, error) {
+	study, ok := params["study"].(map[string]interface{})
+	if ok {
+		caseNumber, caseOk := study["caseNumber"].(string)
+		if caseOk {
+			for i := range research {
+				if research[i].Study.CaseNumber == caseNumber {
+					return research[i], nil
+				}
+			}
+		}
+	}
+	return nil, nil
+}
+
+// @key(fields: "email")
+func UserEntityResolver(params map[string]interface{}) (*model.User, error) {
+	email, ok := params["email"].(string)
+	if ok {
+		for i := range users {
+			var user *model.User
+			if users[i].Email == email {
+				user = users[i]
+			}
+
+			totalProducts, totalSpecified := params["totalProductsCreated"].(float64)
+			if totalSpecified {
+				total := int(totalProducts)
+				user.TotalProductsCreated = &total
+			}
+
+			yearsOfEmployment, yearsSpecified := params["yearsOfEmployment"].(float64)
+			if yearsSpecified {
+				user.YearsOfEmployment = int(yearsOfEmployment)
+			}
+
+			if user != nil {
+				return user, nil
+			}
+		}
+	}
+	return nil, nil
+}