dialect/entsql: add entsql annotation (#876)

dialect/entsql/annotation.go

@@ -0,0 +1,27 @@
+// Copyright 2019-present Facebook Inc. All rights reserved.
+// This source code is licensed under the Apache 2.0 license found
+// in the LICENSE file in the root directory of this source tree.
+
+package entsql
+
+import "github.com/facebook/ent/schema"
+
+// Annotation is a builtin schema annotation for attaching
+// SQL metadata to schema objects for both codegen and runtime.
+type Annotation struct {
+	// The Table option allows overriding the default table
+	// name that is generated by ent. For example:
+	//
+	//	entsql.Annotation{
+	//		Table: "Users",
+	//	}
+	//
+	Table string
+}
+
+// Name describes the annotation name.
+func (Annotation) Name() string {
+	return "EntSQL"
+}
+
+var _ schema.Annotation = (*Annotation)(nil)

ent.go

@@ -46,6 +46,16 @@ type (
 		// Indexes returns the indexes of the schema.
 		Indexes() []Index
 		// Config returns an optional config for the schema.
+		//
+		// Deprecated: the Config method predates the Annotations method and it
+		// is planned be removed in v0.5.0. New code should use Annotations instead.
+		//
+		//	func (T) Annotations() []schema.Annotation {
+		//		return []schema.Annotation{
+		//			entsql.Annotation{Table: "Name"},
+		//		}
+		//	}
+		//
 		Config() Config
 		// Mixin returns an optional list of Mixin to extends
 		// the schema.
@@ -109,6 +119,15 @@ type (
 	//		}
 	//	}
 	//
+	// Deprecated: the Config object predates the schema.Annotation method and it
+	// is planned be removed in v0.5.0. New code should use Annotations instead.
+	//
+	//	func (T) Annotations() []schema.Annotation {
+	//		return []schema.Annotation{
+	//			entsql.Annotation{Table: "Name"},
+	//		}
+	//	}
+	//
 	Config struct {
 		// A Table is an optional table name defined for the schema.
 		Table string

entc/gen/type.go

@@ -6,6 +6,7 @@ package gen
 
 import (
 	"database/sql"
+	"encoding/json"
 	"fmt"
 	"go/token"
 	"go/types"
@@ -17,6 +18,7 @@ import (
 	"unicode"
 
 	"github.com/facebook/ent"
+	"github.com/facebook/ent/dialect/entsql"
 	"github.com/facebook/ent/dialect/sql/schema"
 	"github.com/facebook/ent/entc/load"
 	"github.com/facebook/ent/schema/field"
@@ -222,12 +224,27 @@ func (t Type) Label() string {
 
 // Table returns SQL table name of the node/type.
 func (t Type) Table() string {
+	if table := t.EntSQL().Table; table != "" {
+		return table
+	}
 	if t.schema != nil && t.schema.Config.Table != "" {
 		return t.schema.Config.Table
 	}
 	return snake(rules.Pluralize(t.Name))
 }
 
+// EntSQL returns the EntSQL annotation if exists, or an empty one.
+func (t Type) EntSQL() entsql.Annotation {
+	annotate := entsql.Annotation{}
+	if t.Annotations == nil || t.Annotations[annotate.Name()] == nil {
+		return annotate
+	}
+	if buf, err := json.Marshal(t.Annotations[annotate.Name()]); err == nil {
+		_ = json.Unmarshal(buf, &annotate)
+	}
+	return annotate
+}
+
 // Package returns the package name of this node.
 func (t Type) Package() string {
 	return strings.ToLower(t.Name)

entc/integration/config/config_test.go

@@ -8,6 +8,7 @@ import (
 	"context"
 	"testing"
 
+	"github.com/facebook/ent/dialect/entsql"
 	"github.com/facebook/ent/dialect/sql"
 	"github.com/facebook/ent/entc/integration/config/ent"
 	"github.com/facebook/ent/entc/integration/config/ent/migrate"
@@ -26,8 +27,8 @@ func TestSchemaConfig(t *testing.T) {
 	require.NoError(t, client.Schema.Create(ctx, migrate.WithGlobalUniqueID(true)))
 	client.User.Create().SaveX(ctx)
 
-	// check that the table was created with the given custom name.
-	table := schema.User{}.Config().Table
+	// Check that the table was created with the given custom name.
+	table := schema.User{}.Annotations()[0].(entsql.Annotation).Table
 	query, args := sql.Select().Count().
 		From(sql.Table("sqlite_master")).
 		Where(sql.And(sql.EQ("type", "table"), sql.EQ("name", table))).

entc/integration/config/ent/schema/user.go

@@ -4,16 +4,20 @@
 
 package schema
 
-import "github.com/facebook/ent"
+import (
+	"github.com/facebook/ent"
+	"github.com/facebook/ent/dialect/entsql"
+	"github.com/facebook/ent/schema"
+)
 
 // User holds the schema definition for the User entity.
 type User struct {
 	ent.Schema
 }
 
-// Config of the User.
-func (User) Config() ent.Config {
-	return ent.Config{
-		Table: "Users",
+// Annotations of the User schema.
+func (User) Annotations() []schema.Annotation {
+	return []schema.Annotation{
+		entsql.Annotation{Table: "Users"},
 	}
 }