NO-ISSUE: Verify that GORM embedded structure is always part of conta…

…ining structure (#4730)

There are locations that our code assumes that embedded structure is
always not nil.  This change adds tests to verify it.
For more information: go-gorm/gorm#5431

internal/common/common_test.go

@@ -11,6 +11,7 @@ import (
 	. "github.com/onsi/ginkgo/extensions/table"
 	. "github.com/onsi/gomega"
 	"github.com/openshift/assisted-service/models"
+	"gorm.io/gorm"
 )
 
 const redHatIntermediateChain string = `
@@ -316,6 +317,47 @@ var _ = Describe("Test GetInventoryInterfaces", func() {
 	})
 })
 
+var _ = Describe("db features", func() {
+	var (
+		db *gorm.DB
+	)
+	BeforeEach(func() {
+		db, _ = PrepareTestDB()
+	})
+	AfterEach(func() {
+		CloseDB(db)
+	})
+	Context("embedded struct", func() {
+		type inner struct {
+			String *string
+			Int    int
+		}
+		type Outer struct {
+			Inner *inner `gorm:"embedded;embeddedPrefix:inner_"`
+			ID    int
+		}
+		BeforeEach(func() {
+			Expect(db.Migrator().AutoMigrate(&Outer{})).ToNot(HaveOccurred())
+		})
+		It("default embedded struct is not nil", func() {
+			Expect(db.Create(&Outer{ID: 1}).Error).ToNot(HaveOccurred())
+			var outer Outer
+			Expect(db.Where("inner_string is null and inner_int is null").Take(&outer).Error).ToNot(HaveOccurred())
+			Expect(outer.Inner).ToNot(BeNil())
+			Expect(outer.Inner.Int).To(Equal(0))
+			Expect(outer.Inner.String).To(BeNil())
+		})
+		It("embedded struct with values", func() {
+			Expect(db.Create(&Outer{ID: 1, Inner: &inner{String: swag.String("blah")}}).Error).ToNot(HaveOccurred())
+			var outer Outer
+			Expect(db.Where("inner_string = 'blah'").Take(&outer).Error).ToNot(HaveOccurred())
+			Expect(outer.Inner).ToNot(BeNil())
+			Expect(outer.Inner.Int).To(Equal(0))
+			Expect(outer.Inner.String).To(Equal(swag.String("blah")))
+		})
+	})
+})
+
 func createHost(hostRole models.HostRole, state string) *models.Host {
 	hostId := strfmt.UUID(uuid.New().String())
 	clusterId := strfmt.UUID(uuid.New().String())