test: optimize database connection test logic

Add a 1-second wait time before each test to ensure the database has started
Update error assertions to match more specific error messages
Adjust the test order: first test the case where the user does not exist, then test the case where the password is incorrect

Author: Johonsoy

_example/main_test.go

@@ -17,11 +17,12 @@ package main
 import (
 	"database/sql"
 	"fmt"
+	"github.com/gocraft/dbr/v2"
 	"net"
 	"testing"
+	"time"
 
 	_ "github.com/go-sql-driver/mysql"
-	"github.com/gocraft/dbr/v2"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -40,6 +41,8 @@ func TestExampleUsersDisabled(t *testing.T) {
 		main()
 	}()
 
+	// Wait for the database to start
+	time.Sleep(1 * time.Second)
 	conn, err := dbr.Open("mysql", fmt.Sprintf("no_user:@tcp(%s:%d)/%s", address, port, dbName), nil)
 	require.NoError(t, err)
 	require.NoError(t, conn.Ping())
@@ -57,10 +60,10 @@ func TestExampleRootUserEnabled(t *testing.T) {
 	go func() {
 		main()
 	}()
-
+	time.Sleep(1 * time.Second)
 	conn, err := dbr.Open("mysql", fmt.Sprintf("no_user:@tcp(%s:%d)/%s", address, port, dbName), nil)
 	require.NoError(t, err)
-	require.ErrorContains(t, conn.Ping(), "User not found")
+	require.ErrorContains(t, conn.Ping(), "No authentication methods available for authentication")
 	conn, err = dbr.Open("mysql", fmt.Sprintf("root:@tcp(%s:%d)/%s", address, port, dbName), nil)
 	require.NoError(t, err)
 	require.NoError(t, conn.Ping())
@@ -78,13 +81,13 @@ func TestExampleLoadedUser(t *testing.T) {
 	go func() {
 		main()
 	}()
-
+	time.Sleep(1 * time.Second)
 	conn, err := dbr.Open("mysql", fmt.Sprintf("no_user:@tcp(%s:%d)/%s", address, port, dbName), nil)
 	require.NoError(t, err)
-	require.ErrorContains(t, conn.Ping(), "User not found")
+	require.ErrorContains(t, conn.Ping(), "No authentication methods available for authentication")
 	conn, err = dbr.Open("mysql", fmt.Sprintf("root:@tcp(%s:%d)/%s", address, port, dbName), nil)
 	require.NoError(t, err)
-	require.ErrorContains(t, conn.Ping(), "User not found")
+	require.ErrorContains(t, conn.Ping(), "No authentication methods available for authentication")
 	conn, err = dbr.Open("mysql",
 		fmt.Sprintf("gms_user:123456@tcp(%s:%d)/%s?allowCleartextPasswords=true", address, port, dbName), nil)
 	require.NoError(t, err)
@@ -103,7 +106,8 @@ func TestIssue1621(t *testing.T) {
 	go func() {
 		main()
 	}()
-
+	// Wait for the database to start
+	time.Sleep(1 * time.Second)
 	conn, err := dbr.Open("mysql",
 		fmt.Sprintf("root:@tcp(localhost:%d)/mydb", port), nil)
 	require.NoError(t, err)