entgql: create plugin for gqlgen [Stage1]

entgql/annotation.go

@@ -17,6 +17,7 @@ package entgql
 import (
 	"encoding/json"
 
+	"entgo.io/ent/entc/gen"
 	"entgo.io/ent/schema"
 )
 
@@ -125,6 +126,19 @@ func (a *Annotation) Decode(annotation interface{}) error {
 	return json.Unmarshal(buf, a)
 }
 
+// decodeAnnotation decodes the annotation from the schema.
+func decodeAnnotation(annotations gen.Annotations) (*Annotation, error) {
+	ant := &Annotation{}
+	if annotations == nil || annotations[ant.Name()] == nil {
+		return ant, nil
+	}
+
+	if err := ant.Decode(annotations[ant.Name()]); err != nil {
+		return nil, err
+	}
+	return ant, nil
+}
+
 var (
 	_ schema.Annotation = (*Annotation)(nil)
 	_ schema.Merger     = (*Annotation)(nil)

entgql/extension.go

@@ -37,6 +37,8 @@ import (
 	"github.com/graphql-go/graphql/language/printer"
 	"github.com/graphql-go/graphql/language/source"
 	"github.com/graphql-go/graphql/language/visitor"
+
+	ast2 "github.com/vektah/gqlparser/v2/ast"
 )
 
 type (
@@ -49,6 +51,9 @@ type (
 		hooks      []gen.Hook
 		templates  []*gen.Template
 		scalarFunc func(*gen.Field, gen.Op) string
+
+		schema *ast2.Schema
+		models map[string]string
 	}
 
 	// ExtensionOption allows for managing the Extension configuration
@@ -188,6 +193,14 @@ func WithWhereFilters(b bool) ExtensionOption {
 	}
 }
 
+// WithSchemaGenerator add a hook for generate GQL schema
+func WithSchemaGenerator() ExtensionOption {
+	return func(e *Extension) error {
+		e.hooks = append(e.hooks, e.genSchema())
+		return nil
+	}
+}
+
 // WithMapScalarFunc allows users to provides a custom function that
 // maps an ent.Field (*gen.Field) into its GraphQL scalar type. If the
 // function returns an empty string, the extension fallbacks to the its
@@ -313,6 +326,31 @@ func (e *Extension) isInput(name string) bool {
 	return false
 }
 
+// genSchema returns a new hook for generating
+// the GraphQL schema from the graph.
+func (e *Extension) genSchema() gen.Hook {
+	return func(next gen.Generator) gen.Generator {
+		return gen.GenerateFunc(func(g *gen.Graph) error {
+			if err := next.Generate(g); err != nil {
+				return err
+			}
+
+			genSchema, err := newSchemaGenerator(g)
+			if err != nil {
+				return err
+			}
+			if e.schema, err = genSchema.prepareSchema(); err != nil {
+				return err
+			}
+			if e.models, err = genSchema.genModels(); err != nil {
+				return err
+			}
+
+			return nil
+		})
+	}
+}
+
 // genWhereInputs returns a new hook for generating
 // <T>WhereInputs in the GraphQL schema.
 func (e *Extension) genWhereInputs() gen.Hook {

entgql/internal/todoplugin/cmd/entgqlgen.go

@@ -0,0 +1,77 @@
+// Copyright 2019-present Facebook
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"flag"
+	"log"
+
+	"entgo.io/contrib/entgql"
+	"entgo.io/ent/entc"
+	"entgo.io/ent/entc/gen"
+	"github.com/99designs/gqlgen/api"
+	"github.com/99designs/gqlgen/codegen/config"
+)
+
+func main() {
+	var (
+		schemaPath = flag.String("path", "", "path to schema directory")
+	)
+	flag.Parse()
+	if *schemaPath == "" {
+		log.Fatal("entgqlgen: must specify schema path. use entgqlgen -path ./ent/schema")
+	}
+
+	exEntGQL, err := entgql.NewExtension(
+		entgql.WithSchemaGenerator(),
+	)
+	if err != nil {
+		log.Fatalf("creating entgql extension: %v", err)
+	}
+	err = entc.Generate(*schemaPath, &gen.Config{
+		Header: `
+			// Copyright 2019-present Facebook
+			//
+			// Licensed under the Apache License, Version 2.0 (the "License");
+			// you may not use this file except in compliance with the License.
+			// You may obtain a copy of the License at
+			//
+			//      http://www.apache.org/licenses/LICENSE-2.0
+			//
+			// Unless required by applicable law or agreed to in writing, software
+			// distributed under the License is distributed on an "AS IS" BASIS,
+			// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+			// See the License for the specific language governing permissions and
+			// limitations under the License.
+			//
+			// Code generated by entc, DO NOT EDIT.
+		`,
+	}, entc.Extensions(
+		// EntGQL should be the latest extension in the list
+		exEntGQL,
+	))
+	if err != nil {
+		log.Fatalf("running ent codegen: %v", err)
+	}
+
+	cfg, err := config.LoadConfigFromDefaultLocations()
+	if err != nil {
+		log.Fatalf("failed to load config %v", err)
+	}
+	err = api.Generate(cfg, api.PrependPlugin(exEntGQL.CreatePlugin()))
+	if err != nil {
+		log.Fatalf("running gqlgen: %v", err)
+	}
+}