fix: associations for embedded fields

associations/associations_for_struct.go

@@ -27,6 +27,11 @@ var associationBuilders = map[string]associationBuilder{}
 // it throws an error when it finds a field that does
 // not exist for a model.
 func ForStruct(s interface{}, fields ...string) (Associations, error) {
+	return forStruct(s, s, fields)
+}
+
+// forStruct is a recursive helper that passes the root model down for embedded fields
+func forStruct(parent, s interface{}, fields []string) (Associations, error) {
 	t, v := getModelDefinition(s)
 	if t.Kind() != reflect.Struct {
 		return nil, fmt.Errorf("could not get struct associations: not a struct but %T", s)
@@ -74,7 +79,20 @@ func ForStruct(s interface{}, fields ...string) (Associations, error) {
 
 		// inline embedded field
 		if f.Anonymous {
-			innerAssociations, err := ForStruct(v.Field(i).Interface(), fields...)
+			field := v.Field(i)
+			// we need field to be a pointer, so that we can later set the value
+			// if the embedded field is of type struct {...}, we have to take its address
+			if field.Kind() != reflect.Ptr {
+				field = field.Addr()
+			}
+			if fieldIsNil(field) {
+				// initialize zero value
+				field = reflect.New(field.Type().Elem())
+				// we can only get in this case if v.Field(i) is a pointer type because it could not be nil otherwise
+				//  => it is safe to set it here as is
+				v.Field(i).Set(field)
+			}
+			innerAssociations, err := forStruct(parent, field.Interface(), fields)
 			if err != nil {
 				return nil, err
 			}
@@ -92,11 +110,12 @@ func ForStruct(s interface{}, fields ...string) (Associations, error) {
 		for name, builder := range associationBuilders {
 			tag := tags.Find(name)
 			if !tag.Empty() {
+				pt, pv := getModelDefinition(parent)
 				params := associationParams{
 					field:             f,
-					model:             s,
-					modelType:         t,
-					modelValue:        v,
+					model:             parent,
+					modelType:         pt,
+					modelValue:        pv,
 					popTags:           tags,
 					innerAssociations: fieldsWithInnerAssociation[f.Name],
 				}

docker-compose.yml

@@ -1,4 +1,4 @@
-version: '2'
+version: '2.1'
 
 services:
   mysql:
@@ -25,7 +25,7 @@ services:
       - ./sqldumps:/docker-entrypoint-initdb.d
   cockroach:
     image: cockroachdb/cockroach:v20.2.4
-    user: ${CURRENT_UID:?"Please run as follows 'CURRENT_UID=$(id -u):$(id -g) docker-compose up'"}
+    user: ${CURRENT_UID:?"Please run as follows 'CURRENT_UID=$$(id -u):$$(id -g) docker-compose up'"}
     ports:
       - "26257:26257"
     volumes:

executors_test.go

@@ -1231,6 +1231,150 @@ func Test_Eager_Creation_Without_Associations(t *testing.T) {
 	})
 }
 
+func Test_Eager_Embedded_Struct(t *testing.T) {
+	if PDB == nil {
+		t.Skip("skipping integration tests")
+	}
+	transaction(func(tx *Connection) {
+		r := require.New(t)
+
+		type AssocFields struct {
+			Books        Books     `has_many:"books" order_by:"title asc"`
+			FavoriteSong Song      `has_one:"song" fk_id:"u_id"`
+			Houses       Addresses `many_to_many:"users_addresses"`
+		}
+
+		type User struct {
+			ID        int           `db:"id"`
+			UserName  string        `db:"user_name"`
+			Email     string        `db:"email"`
+			Name      nulls.String  `db:"name"`
+			Alive     nulls.Bool    `db:"alive"`
+			CreatedAt time.Time     `db:"created_at"`
+			UpdatedAt time.Time     `db:"updated_at"`
+			BirthDate nulls.Time    `db:"birth_date"`
+			Bio       nulls.String  `db:"bio"`
+			Price     nulls.Float64 `db:"price"`
+			FullName  nulls.String  `db:"full_name" select:"name as full_name"`
+
+			AssocFields
+		}
+
+		count, _ := tx.Count(&User{})
+		user := User{
+			UserName: "dumb-dumb",
+			Name:     nulls.NewString("Arthur Dent"),
+			AssocFields: AssocFields{
+				Books:        Books{{Title: "The Hitchhiker's Guide to the Galaxy", Description: "Comedy Science Fiction somewhere in Space", Isbn: "PB42"}},
+				FavoriteSong: Song{Title: "Wish You Were Here", ComposedBy: Composer{Name: "Pink Floyd"}},
+				Houses: Addresses{
+					Address{HouseNumber: 155, Street: "Country Lane"},
+				},
+			},
+		}
+
+		err := tx.Eager().Create(&user)
+		r.NoError(err)
+		r.NotZero(user.ID)
+
+		ctx, _ := tx.Count(&User{})
+		r.Equal(count+1, ctx)
+
+		ctx, _ = tx.Count(&Book{})
+		r.Equal(count+1, ctx)
+
+		ctx, _ = tx.Count(&Song{})
+		r.Equal(count+1, ctx)
+
+		ctx, _ = tx.Count(&Address{})
+		r.Equal(count+1, ctx)
+
+		u := User{}
+		q := tx.Eager().Where("name = ?", user.Name.String)
+		err = q.First(&u)
+		r.NoError(err)
+
+		r.Equal(user.Name.String, u.Name.String)
+		r.Len(u.Books, 1)
+		r.Equal(user.Books[0].Title, u.Books[0].Title)
+		r.Equal(user.FavoriteSong.Title, u.FavoriteSong.Title)
+		r.Len(u.Houses, 1)
+		r.Equal(user.Houses[0].Street, u.Houses[0].Street)
+	})
+}
+
+func Test_Eager_Embedded_Ptr_Struct(t *testing.T) {
+	if PDB == nil {
+		t.Skip("skipping integration tests")
+	}
+	transaction(func(tx *Connection) {
+		r := require.New(t)
+
+		type AssocFields struct {
+			Books        Books     `has_many:"books" order_by:"title asc"`
+			FavoriteSong Song      `has_one:"song" fk_id:"u_id"`
+			Houses       Addresses `many_to_many:"users_addresses"`
+		}
+
+		type User struct {
+			ID        int           `db:"id"`
+			UserName  string        `db:"user_name"`
+			Email     string        `db:"email"`
+			Name      nulls.String  `db:"name"`
+			Alive     nulls.Bool    `db:"alive"`
+			CreatedAt time.Time     `db:"created_at"`
+			UpdatedAt time.Time     `db:"updated_at"`
+			BirthDate nulls.Time    `db:"birth_date"`
+			Bio       nulls.String  `db:"bio"`
+			Price     nulls.Float64 `db:"price"`
+			FullName  nulls.String  `db:"full_name" select:"name as full_name"`
+
+			*AssocFields
+		}
+
+		count, _ := tx.Count(&User{})
+		user := User{
+			UserName: "dumb-dumb",
+			Name:     nulls.NewString("Arthur Dent"),
+			AssocFields: &AssocFields{
+				Books:        Books{{Title: "The Hitchhiker's Guide to the Galaxy", Description: "Comedy Science Fiction somewhere in Space", Isbn: "PB42"}},
+				FavoriteSong: Song{Title: "Wish You Were Here", ComposedBy: Composer{Name: "Pink Floyd"}},
+				Houses: Addresses{
+					Address{HouseNumber: 155, Street: "Country Lane"},
+				},
+			},
+		}
+
+		err := tx.Eager().Create(&user)
+		r.NoError(err)
+		r.NotZero(user.ID)
+
+		ctx, _ := tx.Count(&User{})
+		r.Equal(count+1, ctx)
+
+		ctx, _ = tx.Count(&Book{})
+		r.Equal(count+1, ctx)
+
+		ctx, _ = tx.Count(&Song{})
+		r.Equal(count+1, ctx)
+
+		ctx, _ = tx.Count(&Address{})
+		r.Equal(count+1, ctx)
+
+		u := User{}
+		q := tx.Eager().Where("name = ?", user.Name.String)
+		err = q.First(&u)
+		r.NoError(err)
+
+		r.Equal(user.Name.String, u.Name.String)
+		r.Len(u.Books, 1)
+		r.Equal(user.Books[0].Title, u.Books[0].Title)
+		r.Equal(user.FavoriteSong.Title, u.FavoriteSong.Title)
+		r.Len(u.Houses, 1)
+		r.Equal(user.Houses[0].Street, u.Houses[0].Street)
+	})
+}
+
 func Test_Create_UUID(t *testing.T) {
 	if PDB == nil {
 		t.Skip("skipping integration tests")