Added fix/tests for has_many with pointer foreign key (#647)

Co-authored-by: Antonio Pagano <645522+paganotoni@users.noreply.github.com>

pop_test.go

@@ -150,6 +150,8 @@ type Taxi struct {
 	UpdatedAt   time.Time `db:"updated_at"`
 }
 
+type Taxis []Taxi
+
 // Validate gets run every time you call a "Validate*" (ValidateAndSave, ValidateAndCreate, ValidateAndUpdate) method.
 // This method is not required and may be deleted.
 func (b *Book) Validate(tx *Connection) (*validate.Errors, error) {
@@ -180,6 +182,7 @@ type Address struct {
 	HouseNumber int       `db:"house_number"`
 	CreatedAt   time.Time `db:"created_at"`
 	UpdatedAt   time.Time `db:"updated_at"`
+	TaxisToHere Taxis     `has_many:"taxis" fk_id:"to_address_id" order_by:"created_at asc"`
 }
 
 type Addresses []Address

preload_associations.go

@@ -271,8 +271,9 @@ func preloadHasMany(tx *Connection, asoc *AssociationMetaInfo, mmi *ModelMetaInf
 		modelAssociationField := mmi.mapper.FieldByName(mvalue, asoc.Name)
 		for i := 0; i < slice.Elem().Len(); i++ {
 			asocValue := slice.Elem().Index(i)
-			if mmi.mapper.FieldByName(mvalue, "ID").Interface() == mmi.mapper.FieldByName(asocValue, foreignField.Path).Interface() ||
-				reflect.DeepEqual(mmi.mapper.FieldByName(mvalue, "ID"), mmi.mapper.FieldByName(asocValue, foreignField.Path)) {
+			valueField := reflect.Indirect(mmi.mapper.FieldByName(asocValue, foreignField.Path))
+			if mmi.mapper.FieldByName(mvalue, "ID").Interface() == valueField.Interface() ||
+				reflect.DeepEqual(mmi.mapper.FieldByName(mvalue, "ID"), valueField) {
 
 				switch {
 				case modelAssociationField.Kind() == reflect.Slice || modelAssociationField.Kind() == reflect.Array:

preload_associations_test.go

@@ -264,3 +264,39 @@ func Test_New_Implementation_For_BelongsTo_Ptr_Field(t *testing.T) {
 		SetEagerMode(EagerDefault)
 	})
 }
+
+func Test_New_Implementation_For_HasMany_Ptr_Field(t *testing.T) {
+	if PDB == nil {
+		t.Skip("skipping integration tests")
+	}
+	transaction(func(tx *Connection) {
+		a := require.New(t)
+		toAddress1 := Address{HouseNumber: 1, Street: "Destination Ave"}
+		a.NoError(tx.Create(&toAddress1))
+		taxi1 := Taxi{Model: "Ford", ToAddressID: &toAddress1.ID}
+		a.NoError(tx.Create(&taxi1))
+		taxi2 := Taxi{Model: "Honda", ToAddressID: &toAddress1.ID}
+		a.NoError(tx.Create(&taxi2))
+
+		taxiNilToAddress := Taxi{ToAddressID: nil}
+		a.NoError(tx.Create(&taxiNilToAddress))
+
+		toAddress2 := Address{HouseNumber: 2, Street: "Final Way"}
+		a.NoError(tx.Create(&toAddress2))
+		taxi3 := Taxi{Model: "Mazda", ToAddressID: &toAddress2.ID}
+		a.NoError(tx.Create(&taxi3))
+
+		SetEagerMode(EagerPreload)
+		addresses := []Address{}
+		a.NoError(tx.EagerPreload("TaxisToHere").Order("created_at").All(&addresses))
+		a.Len(addresses, 2)
+		a.NotNil(addresses[0].TaxisToHere)
+		a.Len(addresses[0].TaxisToHere, 2)
+		a.Equal(taxi1.Model, addresses[0].TaxisToHere[0].Model)
+		a.Equal(taxi2.Model, addresses[0].TaxisToHere[1].Model)
+		a.NotNil(addresses[1].TaxisToHere)
+		a.Len(addresses[1].TaxisToHere, 1)
+		a.Equal(taxi3.Model, addresses[1].TaxisToHere[0].Model)
+		SetEagerMode(EagerDefault)
+	})
+}