bug: FirstOrCreate's does not return Assign result into struct

main_test.go

@@ -3,33 +3,77 @@ package main
 import (
 	"testing"
 
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
 	"gorm.io/playground/models"
 )
 
 // GORM_REPO: https://github.com/go-gorm/gorm.git
 // GORM_BRANCH: master
-// TEST_DRIVERS: sqlite, mysql, postgres, sqlserver
-
-func TestGORM(t *testing.T) {
-	user := models.User{Name: "jinzhu"}
-
-	DB.Create(&user)
+// TEST_DRIVERS: postgres
 
+// TestGORM_FirstOrCreate tests the FirstOrCreate method
+// this test demonstrates that when using gorm.Expr, the value is not updated in the struct UNLESS you use the Returning clause
+// this behaviour should be fixed or at least documented
+func TestGORM_FirstOrCreate(t *testing.T) {
 	var result models.User
-	if err := DB.First(&result, user.ID).Error; err != nil {
-		t.Errorf("Failed, got error: %v", err)
+	if err := DB.Attrs(models.User{Name: "jinzhu", Age: 18}).FirstOrCreate(&result).Error; err != nil {
+		t.Fatalf("Failed, got error: %v", err)
+	} else {
+		if result.Name != "jinzhu" {
+			t.Errorf("Failed, got user name: %v, expected: %v", result.Name, "jinzhu")
+		} else {
+			t.Logf("Success, got user name: %v, expected: %v", result.Name, "jinzhu")
+		}
 	}
-}
 
-// func TestGORMGen(t *testing.T) {
-// 	user := models.User{Name: "jinzhu2"}
-// 	ctx := context.Background()
+	// setting age to 19 and expect 19 in the struct, this works
+	var update19 models.User
+	age19 := 19
+	if err := DB.Where("name = ?", "jinzhu").Assign("age", age19).FirstOrCreate(&update19).Error; err != nil {
+		t.Fatalf("Failed, got error: %v", err)
+	} else {
+		if update19.Age != 19 {
+			t.Errorf("Failed, got user age: %v, expected: %v", update19.Age, 19)
+		} else {
+			t.Logf("Success, got user age: %v, expected: %v", update19.Age, 19)
+		}
+	}
 
-// 	gorm.G[models.User](DB).Create(ctx, &user)
+	// add 1 to age and expect 20 in the struct... but it fails
+	var update20 models.User
+	var age20 uint = 20
+	if err := DB.Where("name = ?", "jinzhu").Assign("age", gorm.Expr("age + ?", 1)).FirstOrCreate(&update20).Error; err != nil {
+		t.Fatalf("Failed, got error: %v", err)
+	} else {
+		if update20.Age != age20 {
+			t.Errorf("Failed, got user age: %v, expected: %v", update20.Age, age20)
+		} else {
+			t.Logf("Success, got user age: %v, expected: %v", update20.Age, age20)
+		}
+	}
 
-// 	if u, err := gorm.G[models.User](DB).Where(g.User.ID.Eq(user.ID)).First(ctx); err != nil {
-// 		t.Errorf("Failed, got error: %v", err)
-// 	} else if u.Name != user.Name {
-// 		t.Errorf("Failed, got user name: %v", u.Name)
-// 	}
-// }
+	// check if age is 20 in the db... it is!? why did it fail above?
+	var selectUpdate20 models.User
+	if err := DB.Where("name = ?", "jinzhu").First(&selectUpdate20).Error; err != nil {
+		t.Errorf("Failed, got error: %v", err)
+	} else {
+		if selectUpdate20.Age != 20 {
+			t.Errorf("Failed, got user age: %v, expected: %v", selectUpdate20.Age, 20)
+		} else {
+			t.Logf("Success, got user %d with age %v", selectUpdate20.ID, selectUpdate20.Age)
+		}
+	}
+
+	// okay, lets throw a returning in there and... it worked!? lmao
+	var update2 models.User
+	if res := DB.Clauses(clause.Returning{}).Where("name = ?", "jinzhu").Assign("age", gorm.Expr("age + ?", 5)).FirstOrCreate(&update2); res.Error != nil {
+		t.Fatalf("Failed, got error: %v", res.Error)
+	} else {
+		if update2.Age != 25 {
+			t.Errorf("Failed, got user age: %v, expected: %v", update2.Age, 25)
+		} else {
+			t.Logf("Success, got user age: %v, expected: %v", update2.Age, 25)
+		}
+	}
+}