[BUG] Inability to test reliably...

[sean-]

Bug Description

There are a number of global variables used throughout the code base. When trying to use normal gin testing practices where a routing engine is embedded in a Server struct, it is impossible to reconfigure the database or services without encountering panic()'s. For instance:

• go-admin/modules/config/config.go

  Lines 926 to 942 in 2c93e87

  	// Initialize initialize the config.
  	func Initialize(cfg *Config) *Config {
  	initializeLock.Lock()
  	defer initializeLock.Unlock()
  	if atomic.LoadUint32(&count) != 0 {
  	panic("can not initialize config twice")
  	}
  	atomic.StoreUint32(&count, 1)
  	initLogger(SetDefault(cfg))
  	_global = cfg
  	return _global
  	}

• go-admin/modules/service/service.go

  Lines 51 to 56 in 2c93e87

  	func (g List) Add(k string, service Service) {
  	if _, ok := g[k]; ok {
  	panic("service exist")
  	}
  	g[k] = service
  	}

How to reproduce [describe the steps how to reproduce the bug]

Call engine.AddConfig() twice in the same running process:

https://github.com/GoAdminGroup/example/blob/ffac70b8ea3a48080022f0057a128d62a733ebaf/main.go#L58-L63

Run the above, or whatever, in the equivalent of:

import (
  gacfg "github.com/GoAdminGroup/go-admin/modules/config"
  "github.com/GoAdminGroup/go-admin/engine"
)

func Test_MyTest(t *testing.T) {
  cfg1 := &gacfg.Config{}
  cfg2 := &gacfg.Config{}
  eng1 := engine.Default()
  eng2 := engine.Default()
  eng1.AddConfig(cfg1)
  eng2.AddConfig(cfg2)
}

Expect [describe your expect result]

I expect this to work w/o any panics. I'd like to figure out how to use go-admin without sacrificing standard testing practices.

Versions

• GoAdmin version: v1.2.24
• golang version: 1.2.2