Fix panic in rate limit (#226)

* Fix panic for division by zero and negative wait times

* Rename function to something more descriptive

Author: shackra

pkg/sync/syncer.go

@@ -108,10 +108,17 @@ func shouldWaitAndRetry(ctx context.Context, err error) bool {
 		details := st.Details()
 		for _, detail := range details {
 			if rlData, ok := detail.(*v2.RateLimitDescription); ok {
-				wait = time.Until(rlData.ResetAt.AsTime())
-				wait /= time.Duration(rlData.Limit)
+				waitResetAt := time.Until(rlData.ResetAt.AsTime())
+				duration := time.Duration(rlData.Limit)
+				if duration == 0 {
+					duration = 1
+				}
+				waitResetAt /= duration
 				// Round up to the nearest second to make sure we don't hit the rate limit again
-				wait = time.Duration(math.Ceil(wait.Seconds())) * time.Second
+				waitResetAt = time.Duration(math.Ceil(waitResetAt.Seconds())) * time.Second
+				if waitResetAt > 0 {
+					wait = waitResetAt
+				}
 			}
 		}
 	}

pkg/uhttp/wrapper.go

@@ -213,7 +213,7 @@ func WithResponse(response interface{}) DoOption {
 	}
 }
 
-func GRPCWrap(preferredCode codes.Code, resp *http.Response, errs ...error) error {
+func WrapErrorsWithRateLimitInfo(preferredCode codes.Code, resp *http.Response, errs ...error) error {
 	st := status.New(preferredCode, resp.Status)
 
 	description, err := ratelimit.ExtractRateLimitData(resp.StatusCode, &resp.Header)
@@ -296,25 +296,25 @@ func (c *BaseHttpClient) Do(req *http.Request, options ...DoOption) (*http.Respo
 
 	switch resp.StatusCode {
 	case http.StatusRequestTimeout:
-		return resp, GRPCWrap(codes.DeadlineExceeded, resp, optErrs...)
+		return resp, WrapErrorsWithRateLimitInfo(codes.DeadlineExceeded, resp, optErrs...)
 	case http.StatusTooManyRequests, http.StatusServiceUnavailable:
-		return resp, GRPCWrap(codes.Unavailable, resp, optErrs...)
+		return resp, WrapErrorsWithRateLimitInfo(codes.Unavailable, resp, optErrs...)
 	case http.StatusNotFound:
-		return resp, GRPCWrap(codes.NotFound, resp, optErrs...)
+		return resp, WrapErrorsWithRateLimitInfo(codes.NotFound, resp, optErrs...)
 	case http.StatusUnauthorized:
-		return resp, GRPCWrap(codes.Unauthenticated, resp, optErrs...)
+		return resp, WrapErrorsWithRateLimitInfo(codes.Unauthenticated, resp, optErrs...)
 	case http.StatusForbidden:
-		return resp, GRPCWrap(codes.PermissionDenied, resp, optErrs...)
+		return resp, WrapErrorsWithRateLimitInfo(codes.PermissionDenied, resp, optErrs...)
 	case http.StatusNotImplemented:
-		return resp, GRPCWrap(codes.Unimplemented, resp, optErrs...)
+		return resp, WrapErrorsWithRateLimitInfo(codes.Unimplemented, resp, optErrs...)
 	}
 
 	if resp.StatusCode >= 500 && resp.StatusCode <= 599 {
-		return resp, GRPCWrap(codes.Unavailable, resp, optErrs...)
+		return resp, WrapErrorsWithRateLimitInfo(codes.Unavailable, resp, optErrs...)
 	}
 
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		return resp, GRPCWrap(codes.Unknown, resp, append(optErrs, fmt.Errorf("unexpected status code: %d", resp.StatusCode))...)
+		return resp, WrapErrorsWithRateLimitInfo(codes.Unknown, resp, append(optErrs, fmt.Errorf("unexpected status code: %d", resp.StatusCode))...)
 	}
 
 	if req.Method == http.MethodGet && resp.StatusCode == http.StatusOK {