Merge pull request #2991 from Johonsoy/fix_example_run_error

test: optimize database connection test logic

Author: zachmu

_example/main_test.go

@@ -18,6 +18,7 @@ import (
 	"database/sql"
 	"fmt"
 	"testing"
+	"time"
 
 	_ "github.com/go-sql-driver/mysql"
 	"github.com/gocraft/dbr/v2"
@@ -42,6 +43,8 @@ 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())
@@ -60,7 +63,6 @@ func TestExampleRootUserEnabled(t *testing.T) {
 	go func() {
 		main()
 	}()
-
 	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")
@@ -82,7 +84,6 @@ func TestExampleLoadedUser(t *testing.T) {
 	go func() {
 		main()
 	}()
-
 	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")
@@ -108,7 +109,6 @@ func TestIssue1621(t *testing.T) {
 	go func() {
 		main()
 	}()
-
 	conn, err := dbr.Open("mysql",
 		fmt.Sprintf("root:@tcp(localhost:%d)/mydb", port), nil)
 	require.NoError(t, err)