[Feature]: Pass user custom context to http.NewRequest in the client.go

[Halimao]

First of all, thank you for making this great SDK.

I want to pass different timeout contexts to different bybit APIs. Is it possible to do this?

This will break down the api, but passing custom context should be better than using default context.Background().

[hirokisan]

@Halimao Thank you for your comment!

It should be possible to achieve this by using WithHTTPClient.

For example, it might look something like this.

type customTransport struct {
  transport http.RoundTripper
}

func (t *customTransport) RoundTrip(req *http.Request) (*http.Response, error) {
  ctx, cancel := context.WithTimeout(req.Context(), 2*time.Second)
  defer cancel()

  req = req.WithContext(ctx)
  return t.transport.RoundTrip(req)
}

client := bybit.NewClient().WithHTTPClient(&http.Client{
  Transport: &customTransport{
    transport: http.DefaultTransport,
  },
})

ref. #74 (comment)

[Halimao]

I am sorry, I think changing http client timeout will affect all api requests based on this client. Do I miss something here?

For example, I wanna set 5s timeout for 'cancel order' api request, but 1s timeout for 'create order' api request. How to do this with custom http client?

[hirokisan]

@Halimao

I see.

I think it is possible to judge by the path.

How about something like this?

func (t *customTransport) RoundTrip(req *http.Request) (*http.Response, error) {
    var timeout time.Duration

    switch req.URL.Path {
    case "/v5/order/cancel":
        timeout = 5 * time.Second
    case "/v5/order/create":
        timeout = 1 * time.Second
    default:
        timeout = 2 * time.Second
    }

    ctx, cancel := context.WithTimeout(req.Context(), timeout)
    defer cancel()

    req = req.WithContext(ctx)
    return t.transport.RoundTrip(req)
}

[Halimao]

@hirokisan Okay, I thought about this way before, but this is indeed unacceptable to me.

Actually, I prefer to implement through the way following😁:

Passing context through the whole call chain is always more flexible.

[hirokisan]

I see. It's like this, isn't it?

type V5OrderServiceI interface {
  CreateOrder(context.Context, V5CreateOrderParam) (*V5CreateOrderResponse, error)
  CancelOrder(context.Context, V5CancelOrderParam) (*V5CancelOrderResponse, error)
}

It seems to me that we should be cautious because of the changes that will be made to the I/F.

However, the change itself seems to be a good idea from a flexibility standpoint.

[Halimao]

Yes, this is an api-breaking change.

Maybe we could add this feature if there is a plan for the next version v3 😁