Interface Panic

[hoc-tiki]

receiving a response (I don't know what exactly response from third party), and I've got a panic
So what should I need to avoid this panic. Thank you

Code

resty.
		SetDebug(false).
		SetTimeout(1*time.Minute).
		R().
		SetBody(param).
		SetHeader("authorization", <api token>).
		SetResult(&response).
		SetError(&responseErr).
		Post(v1_pathInternalAsaDiscountRefund)

Error

panic: interface conversion: interface {} is nil, not string
goroutine 2463 [running]:
github.com/go-resty/resty/v2.responseLogger(0xc0001ae960, 0xc00b441d10)
/go/pkg/mod/github.com/go-resty/resty/[email protected]/middleware.go:301 +0x75c
github.com/go-resty/resty/v2.(*Client).execute(0xc0001ae960, 0xc00b4511e0)
/go/pkg/mod/github.com/go-resty/resty/[email protected]/client.go:972 +0xbe4
github.com/go-resty/resty/v2. (*Request).Execute(0xc00b4511e0,
{0x1150590?, 0xc00b4d95a0?}, {0x117ec20, 0x21})
/go/pkg/mod/github.com/go-resty/resty/[email protected]/request.go:758 +0x5c5 github.com/go-resty/resty/v2. (*Request). Post(...)
/go/pkg/mod/github.com/go-resty/resty/[email protected]/request.go:699

[Greyh4t]

This problem can be avoided by calling SetDebug once when *resty.Client is initialized globally.
Otherwise, if you share the same *resty.Client, and SetDebug and send requests concurrently, you may encounter this problem.
I think this is a bug in resty, because SetDebug is not concurrently safe. When SetDebug is called concurrently, Request.values may be empty. At this time, the responseLogger method will definitely panic when fetching data from it.
See also:
https://github.com/go-resty/resty/blob/master/middleware.go#L281
https://github.com/go-resty/resty/blob/master/middleware.go#L300

This is a trigger example：

var wg sync.WaitGroup
c := resty.New()
for i := 0; i < 10; i++ {
	wg.Add(1)
	go func(i int) {
		if i%2 == 0 {
			c.SetDebug(true)
		} else {
			c.SetDebug(false)
		}
		_, err := c.R().Get("https://www.feishu.cn")
		fmt.Println(err)
		wg.Done()
	}(i)
}
wg.Wait()

[hoc-tiki]

Thank for your answer, but why you don't return an error if it's empty. This error makes crashing app

[Greyh4t]

Thank for your answer, but why you don't return an error if it's empty. This error makes crashing app

I am not a developer of resty, I encountered the same problem as you, the reason for this problem is that resty encountered an unexpected assertion, resty needs to fix it

[jeevatkm]

@Greyh4t Thanks for the analysis and sample test case.

@hoc-tiki @Greyh4t I will look into this.

[jeevatkm]

@Greyh4t @hoc-tiki I have looked at it. Having too many RWMutex is not good, so I'm going to add the SetDebug method at the request level.