feat(graphql): support directives (#33)

command.go

@@ -202,6 +202,15 @@ func (m *plugin) GenerateCode(data *codegen.Data) error {
 			"gmethod": func(from, to string) string {
 				return m.types.resolver[from][to][2]
 			},
+			"gdpkg": func(name string) string {
+				return m.types.directives["@"+name][0]
+			},
+			"gdtyp": func(name string) string {
+				return m.types.directives["@"+name][1]
+			},
+			"gdmethod": func(name string) string {
+				return m.types.directives["@"+name][2]
+			},
 		},
 		PackageDoc: "//+build !graphql\n",
 		Template: `
@@ -230,6 +239,9 @@ type {{$root.TypeName}} struct {
 			{{lcFirst $root.TypeName}}{{$object.Name}} *{{lcFirst $root.TypeName}}{{$object.Name}}
 		{{- end }}
 	{{- end }}
+	{{ range $directive := .AllDirectives }}
+		{{$directive.Name}}Resolver *{{lookupImport (gdpkg $directive.Name)}}.{{gdtyp $directive.Name}}
+	{{- end }}
 }
 
 func (r *{{$root.TypeName}}) Inject (
@@ -238,12 +250,26 @@ func (r *{{$root.TypeName}}) Inject (
 			{{lcFirst $root.TypeName}}{{$object.Name}} *{{lcFirst $root.TypeName}}{{$object.Name}},
 		{{- end }}
 	{{- end }}
+	{{ range $directive := .AllDirectives }}
+		{{$directive.Name}}Resolver *{{lookupImport (gdpkg $directive.Name)}}.{{gdtyp $directive.Name}},
+	{{- end }}
 ) {
 	{{- range $object := .Objects }}
 		{{- if $object.HasResolvers }}
 			r.{{lcFirst $root.TypeName}}{{$object.Name}} = {{lcFirst $root.TypeName}}{{$object.Name}}
 		{{- end }}
 	{{- end }}
+	{{ range $directive := .AllDirectives }}
+		r.{{$directive.Name}}Resolver = {{$directive.Name}}Resolver
+	{{- end }}
+}
+
+func (r *{{$root.TypeName}}) directives() DirectiveRoot {
+	return DirectiveRoot{
+		{{ range $directive := .AllDirectives -}}
+			{{ucFirst $directive.Name}}: r.{{$directive.Name}}Resolver.{{gdmethod $directive.Name}},
+		{{end}}
+	}
 }
 
 {{ range $object := .Objects -}}

example/graphql/schema/flamingo.me_graphql_example_user_interfaces_graphql-Service.graphql

@@ -4,7 +4,9 @@ type User {
     attributes: User_Attributes!
 }
 
-type User_Attributes {
+directive @userAttributeFilter(prefix: String!) on OBJECT
+
+type User_Attributes @userAttributeFilter(prefix: "secret") {
     keys: [String!]!
     get(key: String!): String!
 }

example/user/infrastructure/user.go

@@ -15,7 +15,8 @@ func (us *UserServiceImpl) UserByID(_ context.Context, id string) (*domain.User,
 		Name:      "User " + id,
 		Nicknames: []string{"nick", id},
 		Attributes: map[string]interface{}{
-			"movie": "starwars",
+			"movie":        "starwars",
+			"secret_crush": "r2d2",
 		},
 	}, nil
 }

example/user/interfaces/graphql/resolver.go

@@ -2,10 +2,15 @@ package graphql
 
 import (
 	"context"
+	"errors"
+	"strings"
 
 	"flamingo.me/graphql/example/user/domain"
+	"github.com/99designs/gqlgen/graphql"
 )
 
+var errNoAttributeReturned = errors.New("no attributes returned")
+
 // UserQueryResolver resolver for the user service
 type UserQueryResolver struct {
 	userService domain.UserService
@@ -21,3 +26,24 @@ func (r *UserQueryResolver) Inject(userService domain.UserService) *UserQueryRes
 func (r *UserQueryResolver) User(ctx context.Context, id string) (*domain.User, error) {
 	return r.userService.UserByID(ctx, id)
 }
+
+// UserAttributeFilter directive
+func (r *UserQueryResolver) UserAttributeFilter(ctx context.Context, obj interface{}, next graphql.Resolver, prefix string) (res interface{}, err error) {
+	rawAttributes, err := next(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	attributes, ok := rawAttributes.(domain.Attributes)
+	if !ok {
+		return nil, errNoAttributeReturned
+	}
+
+	for k := range attributes {
+		if strings.HasPrefix(k, prefix) {
+			delete(attributes, k)
+		}
+	}
+
+	return attributes, nil
+}

example/user/interfaces/graphql/schema.graphql

@@ -4,7 +4,9 @@ type User {
     attributes: User_Attributes!
 }
 
-type User_Attributes {
+directive @userAttributeFilter(prefix: String!) on OBJECT
+
+type User_Attributes @userAttributeFilter(prefix: "secret") {
     keys: [String!]!
     get(key: String!): String!
 }

example/user/interfaces/graphql/service.go

@@ -1,7 +1,6 @@
 package graphql
 
 import (
-	// embed schema.grapqhl
 	_ "embed"
 
 	"flamingo.me/graphql"
@@ -24,4 +23,6 @@ func (*Service) Types(types *graphql.Types) {
 	types.Map("User", domain.User{})
 	types.Map("User_Attributes", domain.Attributes{})
 	types.Resolve("Query", "User", UserQueryResolver{}, "User")
+
+	types.Directive("@userAttributeFilter", UserQueryResolver{}, "UserAttributeFilter")
 }

go.mod

@@ -17,7 +17,6 @@ require (
 	cuelang.org/go v0.0.15 // indirect
 	github.com/agnivade/levenshtein v1.1.1 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
-	github.com/boj/redistore v0.0.0-20180917114910-cd5dcc76aeff // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/cockroachdb/apd/v2 v2.0.1 // indirect
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
@@ -27,15 +26,11 @@ require (
 	github.com/go-redis/redis/v8 v8.11.5 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
-	github.com/gomodule/redigo v2.0.0+incompatible // indirect
 	github.com/gorilla/securecookie v1.1.1 // indirect
 	github.com/gorilla/sessions v1.2.1 // indirect
 	github.com/gorilla/websocket v1.5.0 // indirect
 	github.com/hashicorp/golang-lru v0.5.4 // indirect
 	github.com/inconshreveable/mousetrap v1.0.1 // indirect
-	github.com/labstack/gommon v0.0.0-20180613044413-d6898124de91 // indirect
-	github.com/mattn/go-colorable v0.1.13 // indirect
-	github.com/mattn/go-isatty v0.0.16 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
 	github.com/mitchellh/mapstructure v1.4.3 // indirect
 	github.com/mpvl/unique v0.0.0-20150818121801-cbe035fff7de // indirect