testing gorm with go-sqlmock issue comparing queries with mock.ExpectQuery and regexp.QuoteMeta

Question

I am having problems comparing the query expected with the true query of gorm, this is my code:

package repository

import (
    "regexp"
    "testing"

    "github.com/DATA-DOG/go-sqlmock"
    "YOUR_GO_ROOT/pkg/domain"
    "github.com/stretchr/testify/assert"
    "gorm.io/driver/mysql"
    "gorm.io/gorm"
)


var successGetTransaction domain.Transaction = domain.Transaction{
    ID:          2,
    BuyerID:     2,
    SellerID:    5,
    ItemID:      2,
    MessageID:   2,
    ExpiredDate: "2022-09-010 01:01:00",
    CreatedAt:   "2022-09-08 01:01:00",
}

func TestSuccessGetTransactionByID(t *testing.T) {

    db, mock, err := sqlmock.New()
    assert.NoError(t, err)
    gdb, err := gorm.Open(mysql.New(mysql.Config{
        Conn:                      db,
        SkipInitializeWithVersion: true,
    }), &gorm.Config{})
    assert.NoError(t, err)

    rows := sqlmock.NewRows([]string{"id", "buyer_id", "seller_id", "item_id", "message_id", "expired_date", "created_at"}).
        AddRow(2, 2, 5, 2, 2, "2022-09-010 01:01:00", "2022-09-08 01:01:00")
    mock.ExpectQuery(regexp.QuoteMeta("SELECT * FROM transaction WHERE id = ?;")).WillReturnRows(rows)

    repo := DefaultClient(gdb)
    actualSectionList, _ := repo.GetTransactionByID(2)
    
    assert.Equal(t, successGetTransaction, actualSectionList, "ambas listas deberian ser iguales")
    assert.NoError(t, mock.ExpectationsWereMet())
}

here is the module domain:

package domain

type Transaction struct {
    ID          int64  `gorm:"primaryKey;column:id"`
    BuyerID     int64  `gorm:"column:buyer_id"`
    SellerID    int64  `gorm:"column:seller_id"`
    ItemID      int    `gorm:"column:item_id"`
    MessageID   int    `gorm:"column:message_id"`
    ExpiredDate string `gorm:"column:expired_date"`
    CreatedAt   string `gorm:"column:created_at"`
}

func (Transaction) TableName() string {
    return "transaction"
}

type TransactionStatus struct {
    ID             int64  `gorm:"primaryKey;column:id"`
    TransactionID  int64  `gorm:"column:transaction_id"`
    Status         int    `gorm:"column:status"`
    NotificationID int    `gorm:"column:notification_id"`
    CreatedAt      string `gorm:"column:created_at"`
}

func (TransactionStatus) TableName() string {
    return "transaction_status"
}

and here the function that I am testing:

package repository

import (
    "fmt"

    "YOUR_GO_ROOT/pkg/domain"
    "gorm.io/gorm"
)

type RepositoryClient interface {
    GetTransactionByID(id int) (domain.Transaction, error)
}

type repositoryClient struct {
    db *gorm.DB
}

func DefaultClient(db *gorm.DB) RepositoryClient {
    return &repositoryClient{
        db: db,
    }
}

func (rc repositoryClient) GetTransactionByID(id int) (domain.Transaction, error) {
    trans := domain.Transaction{}
    status := rc.db.Where("id = ?", id).Find(&trans)

    if status.Error != nil {
        return domain.Transaction{}, status.Error
    }
    if trans == (domain.Transaction{}) {
        return domain.Transaction{}, fmt.Errorf("error finding transaction id %v", id)
    }
    return trans, nil
}

this is the error that I am getting from the console:

Query: could not match actual sql: "SELECT * FROM `transaction` WHERE id = ?" with expected regexp "SELECT \* FROM transaction WHERE id = \?;"[0m[33m[0.218ms] [34;1m[rows:0][0m SELECT * FROM `transaction` WHERE id = 2

in this seccion exist an answer that is substitute with "SELECT(.*)" but according to what i had read that is not a real solution

Answer 1

Let me try to help to figure out the issue. I downloaded all of your files and the domain.go and the repository.go look fine to me.
However, I found some small issues in the repository_test.go file:

1. Backticks missing in the SQL query you wrote
2. An extra ; at the end of the query
3. The invocation to the method WithArgs(2) is missing

If you adjusted these small issues you should have a code that looks like this one:

// ... omitted for brevity
func TestSuccessGetTransactionByID(t *testing.T) {
    db, mock, err := sqlmock.New()
    assert.NoError(t, err)
    gdb, err := gorm.Open(mysql.New(mysql.Config{
        Conn:                      db,
        SkipInitializeWithVersion: true,
    }), &gorm.Config{})
    assert.NoError(t, err)

    rows := sqlmock.NewRows([]string{"id", "buyer_id", "seller_id", "item_id", "message_id", "expired_date", "created_at"}).AddRow(2, 2, 5, 2, 2, "2022-09-010 01:01:00", "2022-09-08 01:01:00")
    mock.ExpectQuery(regexp.QuoteMeta("SELECT * FROM `transaction` WHERE id = ?")).WithArgs(2).WillReturnRows(rows)

    repo := DefaultClient(gdb)
    actualSectionList, _ := repo.GetTransactionByID(2)

    assert.Equal(t, successGetTransaction, actualSectionList, "ambas listas deberian ser iguales")
    assert.NoError(t, mock.ExpectationsWereMet())
}

Then, if you try to run the test it should work.
Let me know if this solves your issue, thanks!