unstaged - do not merge

executors_test.go

@@ -1193,7 +1193,7 @@ func Test_Eager_Creation_Without_Associations(t *testing.T) {
 	transaction(func(tx *Connection) {
 		r := require.New(t)
 		code := CourseCode{
-			Course: Course{},
+			Course: &Course{},
 		}
 
 		err := tx.Eager().Create(&code)

pop_test.go

@@ -291,14 +291,30 @@ type Course struct {
 }
 
 type CourseCode struct {
-	ID        uuid.UUID `json:"id" db:"id"`
-	CreatedAt time.Time `json:"created_at" db:"created_at"`
-	UpdatedAt time.Time `json:"updated_at" db:"updated_at"`
-	CourseID  uuid.UUID `json:"course_id" db:"course_id"`
-	Course    Course    `json:"-" belongs_to:"course"`
+	ID        uuid.UUID     `json:"id" db:"id"`
+	CreatedAt time.Time     `json:"created_at" db:"created_at"`
+	UpdatedAt time.Time     `json:"updated_at" db:"updated_at"`
+	CourseID  uuid.NullUUID `json:"course_id" db:"course_id"`
+	Course    *Course       `json:"course" belongs_to:"course" fk_id:"CourseID"`
+	ClassID   uuid.UUID     `json:"class_id" db:"class_id"`
 	// Course Course `belongs_to:"course"`
 }
 
+type Teacher struct {
+	ID           uuid.UUID `json:"id" db:"id"`
+	Name         string    `json:"name" db:"name"`
+	CurrentClass *Class    `json:"class" has_one:"class" fk_id:"current_teacher_id"`
+	Classes      []Class   `json:"classes" has_many:"class" fk_id:"teacher_id"`
+}
+
+type Class struct {
+	ID               uuid.UUID     `json:"id" db:"id"`
+	Topic            string        `json:"topic" db:"topic"`
+	TeacherID        uuid.NullUUID `json:"teachers_id" db:"teacher_id"`
+	CurrentTeacherID uuid.UUID     `json:"current_teachers_id" db:"current_teacher_id"`
+	CourseCodes      []CourseCode  `json:"course_code_id" has_many:"course_codes"`
+}
+
 type ValidatableCar struct {
 	ID        int64     `db:"id"`
 	Name      string    `db:"name"`

preload_associations.go

@@ -360,7 +360,9 @@ func preloadBelongsTo(tx *Connection, asoc *AssociationMetaInfo, mmi *ModelMetaI
 	fkids := []interface{}{}
 	mmi.iterate(func(val reflect.Value) {
 		if !isFieldNilPtr(val, fi) {
-			fkids = append(fkids, mmi.mapper.FieldByName(val, fi.Path).Interface())
+			if realValue := mmi.mapper.FieldByName(val, fi.Path).Interface(); !IsZeroOfUnderlyingType(realValue) {
+				fkids = append(fkids, realValue)
+			}
 		}
 	})
 
@@ -376,7 +378,8 @@ func preloadBelongsTo(tx *Connection, asoc *AssociationMetaInfo, mmi *ModelMetaI
 	q.eagerFields = []string{}
 
 	slice := asoc.toSlice()
-	err := q.Where(fmt.Sprintf("%s in (?)", fk), fkids).All(slice.Interface())
+	vals := slice.Interface()
+	err := q.Where(fmt.Sprintf("%s in (?)", fk), fkids).All(vals)
 	if err != nil {
 		return err
 	}

preload_associations_test.go

@@ -1,10 +1,10 @@
 package pop
 
 import (
-	"testing"
-
 	"github.com/gobuffalo/nulls"
+	"github.com/gofrs/uuid"
 	"github.com/stretchr/testify/require"
+	"testing"
 )
 
 func Test_New_Implementation_For_Nplus1(t *testing.T) {
@@ -82,7 +82,7 @@ func Test_New_Implementation_For_Nplus1_With_UUID(t *testing.T) {
 			courses = append(courses, course)
 			if i == 0 {
 				a.NoError(tx.Create(&CourseCode{
-					CourseID: course.ID,
+					CourseID: uuid.NullUUID{UUID: course.ID, Valid: true},
 				}))
 			}
 		}
@@ -113,6 +113,42 @@ func Test_New_Implementation_For_Nplus1_With_UUID(t *testing.T) {
 	})
 }
 
+func Test_New_Implementation_For_Nplus1_With_NullUUIDs_And_FK_ID(t *testing.T) {
+	if PDB == nil {
+		t.Skip("skipping integration tests")
+	}
+	transaction(func(tx *Connection) {
+		teacher := &Teacher{
+			Name: "Alice",
+			Class: &Class{
+				Topic:       "Is math related to science?",
+				CourseCodes: []CourseCode{{}},
+			},
+		}
+
+		a := require.New(t)
+
+		a.NoError(tx.Create(teacher))
+		for k, cc := range teacher.Class.CourseCodes {
+			if cc.Course != nil {
+				a.NoError(tx.Create(cc.Course))
+				teacher.Class.CourseCodes[k].CourseID = uuid.NullUUID{Valid: true, UUID: cc.Course.ID}
+			}
+		}
+		teacher.Class.TeacherID = uuid.NullUUID{UUID: teacher.ID, Valid: true}
+		a.NoError(tx.Eager().Create(teacher.Class))
+
+		var alice Teacher
+		a.NoError(tx.EagerPreload(
+			"Class.CourseCodes.Course",
+		).First(&alice))
+
+		aliceClass := alice.Class
+		a.Len(aliceClass.CourseCodes, 1)
+		a.Nil(aliceClass.CourseCodes[0].Course)
+	})
+}
+
 func Test_New_Implementation_For_Nplus1_Single(t *testing.T) {
 	if PDB == nil {
 		t.Skip("skipping integration tests")

testdata/migrations/20181104140606_course_codes.up.fizz

@@ -1,5 +1,6 @@
 create_table("course_codes") {
   t.Column("id", "uuid", {"primary": true})
-  t.Column("course_id", "uuid", {})
+  t.Column("course_id", "uuid", {"null":true})
+  t.Column("class_id", "uuid")
   t.Timestamps()
-}
+}

testdata/migrations/20210104145902_teachers.down.fizz

@@ -0,0 +1 @@
+drop_table('teachers')

testdata/migrations/20210104145902_teachers.up.fizz

@@ -0,0 +1,13 @@
+create_table("teachers") {
+  t.Column("id", "uuid", {"primary": true})
+  t.Column("name", "string")
+  t.DisableTimestamps()
+}
+
+create_table("classes") {
+  t.Column("id", "uuid", {"primary": true})
+  t.Column("topic", "string")
+  t.Column("teacher_id", "uuid", {"null": true})
+  t.ForeignKey("teacher_id", {"teachers": ["id"]}, {})
+  t.DisableTimestamps()
+}