entc/gen: add support for MapBulkCreate (#3696)

examples/privacyadmin/ent/client.go

@@ -11,6 +11,7 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"reflect"
 
 	"entgo.io/ent"
 	"entgo.io/ent/examples/privacyadmin/ent/migrate"
@@ -227,6 +228,21 @@ func (c *UserClient) CreateBulk(builders ...*UserCreate) *UserCreateBulk {
 	return &UserCreateBulk{config: c.config, builders: builders}
 }
 
+// MapCreateBulk creates a bulk creation builder from the given slice. For each item in the slice, the function creates
+// a builder and applies setFunc on it.
+func (c *UserClient) MapCreateBulk(slice any, setFunc func(*UserCreate, int)) *UserCreateBulk {
+	rv := reflect.ValueOf(slice)
+	if rv.Kind() != reflect.Slice {
+		return &UserCreateBulk{err: fmt.Errorf("calling to UserClient.MapCreateBulk with wrong type %T, need slice", slice)}
+	}
+	builders := make([]*UserCreate, rv.Len())
+	for i := 0; i < rv.Len(); i++ {
+		builders[i] = c.Create()
+		setFunc(builders[i], i)
+	}
+	return &UserCreateBulk{config: c.config, builders: builders}
+}
+
 // Update returns an update builder for User.
 func (c *UserClient) Update() *UserUpdate {
 	mutation := newUserMutation(c.config, OpUpdate)

examples/privacyadmin/ent/user_create.go

@@ -122,11 +122,15 @@ func (uc *UserCreate) createSpec() (*User, *sqlgraph.CreateSpec) {
 // UserCreateBulk is the builder for creating many User entities in bulk.
 type UserCreateBulk struct {
 	config
+	err      error
 	builders []*UserCreate
 }
 
 // Save creates the User entities in the database.
 func (ucb *UserCreateBulk) Save(ctx context.Context) ([]*User, error) {
+	if ucb.err != nil {
+		return nil, ucb.err
+	}
 	specs := make([]*sqlgraph.CreateSpec, len(ucb.builders))
 	nodes := make([]*User, len(ucb.builders))
 	mutators := make([]Mutator, len(ucb.builders))