dont panic on nil ErrorHandler

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

go.mod

@@ -3,7 +3,7 @@ module github.com/unistack-org/micro-server-http/v3
 go 1.13
 
 require (
-	github.com/unistack-org/micro/v3 v3.2.14
+	github.com/unistack-org/micro/v3 v3.2.15
 	golang.org/x/net v0.0.0-20210226172049-e18ecbb05110
 )
 

go.sum

@@ -1,26 +1,13 @@
-github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/ef-ds/deque v1.0.4/go.mod h1:gXDnTC3yqvBcHbq2lcExjtAcVrOnJCbMcZXmuj8Z4tg=
-github.com/go-test/deep v1.0.7/go.mod h1:QV8Hv/iy04NyLBxAdO9njL0iVPN1S4d/A3NVv1V36o8=
-github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.2.0 h1:qJYtXnJRWmpe7m/3XlyhrsLrEURqHRM2kxzoxXqyUDs=
 github.com/google/uuid v1.2.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/heimdalr/dag v1.0.1/go.mod h1:t+ZkR+sjKL4xhlE1B9rwpvwfo+x+2R0363efS+Oghns=
 github.com/imdario/mergo v0.3.11/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
-github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
-github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/silas/dag v0.0.0-20210121180416-41cf55125c34/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
-github.com/unistack-org/micro/v3 v3.2.14 h1:BD7JR2W0WlJvJgHN3uPWrE/vNAGyxhIQrIODeDCfoSk=
-github.com/unistack-org/micro/v3 v3.2.14/go.mod h1:3j13mSd/rILNjyP0tEVtDxyDkJBtnHUXShNCuPHkC5A=
-golang.org/x/net v0.0.0-20210119194325-5f4716e94777/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20210224082022-3d97a244fca7 h1:OgUuv8lsRpBibGNbSizVwKWlysjaNzmC9gYMhPVfqFM=
-golang.org/x/net v0.0.0-20210224082022-3d97a244fca7/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20210226101413-39120d07d75e h1:jIQURUJ9mlLvYwTBtRHm9h58rYhSonLvRvgAnP8Nr7I=
-golang.org/x/net v0.0.0-20210226101413-39120d07d75e/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+github.com/unistack-org/micro/v3 v3.2.15 h1:9Wg6FAFVPUijAm5ZFF+y4oYEd8zd/Pp48QwmMrSs074=
+github.com/unistack-org/micro/v3 v3.2.15/go.mod h1:y+fV+BPNK2IqGoLquRU396jTYifG0HCw3zxFfI4E0dc=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110 h1:qWPm9rbaAMKs8Bq/9LRpbMqxWRVUAQwMI9fVrssnTfw=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -28,5 +15,4 @@ golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9sn
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

handler.go

@@ -67,7 +67,7 @@ func (h *httpHandler) Options() server.HandlerOptions {
 }
 
 func (h *httpHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	ctx := r.Context()
+	ctx := metadata.NewContext(r.Context(), nil)
 
 	defer r.Body.Close()
 
@@ -187,17 +187,21 @@ func (h *httpHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	var scode int
 	// define the handler func
-	fn := func(ctx context.Context, req server.Request, rsp interface{}) (err error) {
-		ctx = context.WithValue(ctx, rspCodeKey{}, &rspCodeVal{})
-		ctx = metadata.NewIncomingContext(ctx, md)
-		returnValues = function.Call([]reflect.Value{hldr.rcvr, hldr.mtype.prepareContext(ctx), reflect.ValueOf(argv.Interface()), reflect.ValueOf(rsp)})
+	fn := func(fctx context.Context, req server.Request, rsp interface{}) (err error) {
+		fctx = context.WithValue(fctx, rspCodeKey{}, &rspCodeVal{})
+		fctx = metadata.NewIncomingContext(fctx, md)
+		returnValues = function.Call([]reflect.Value{hldr.rcvr, hldr.mtype.prepareContext(fctx), reflect.ValueOf(argv.Interface()), reflect.ValueOf(rsp)})
 
-		scode = GetRspCode(ctx)
+		scode = GetRspCode(fctx)
 		// The return value for the method is an error.
 		if rerr := returnValues[0].Interface(); rerr != nil {
 			err = rerr.(error)
 		}
 
+		if md, ok := metadata.FromOutgoingContext(fctx); ok {
+			metadata.SetOutgoingContext(ctx, md)
+		}
+
 		return err
 	}
 

http.go

@@ -2,6 +2,7 @@
 package http
 
 import (
+	"context"
 	"crypto/tls"
 	"errors"
 	"fmt"
@@ -85,6 +86,10 @@ func (h *httpServer) NewHandler(handler interface{}, opts ...server.HandlerOptio
 		sopts: h.opts,
 	}
 
+	hdlr.errorHandler = DefaultErrorHandler
+	if fn, ok := options.Context.Value(errorHandlerKey{}).(func(ctx context.Context, s server.Handler, w http.ResponseWriter, r *http.Request, err error, status int)); ok && fn != nil {
+		hdlr.errorHandler = fn
+	}
 	tp := reflect.TypeOf(handler)
 
 	/*

options.go

@@ -13,14 +13,17 @@ type rspCodeVal struct {
 	code int
 }
 
+// SetError pass error to caller
 func SetError(err interface{}) error {
 	return &Error{err: err}
 }
 
+// Error struct holds error
 type Error struct {
 	err interface{}
 }
 
+// Error func for error interface
 func (err *Error) Error() string {
 	return fmt.Sprintf("%v", err.err)
 }
@@ -43,12 +46,21 @@ func GetRspCode(ctx context.Context) int {
 
 type middlewareKey struct{}
 
+// Middleware passes http middlewares
 func Middleware(mw ...func(http.Handler) http.Handler) server.Option {
 	return server.SetOption(middlewareKey{}, mw)
 }
 
 type serverKey struct{}
 
+// Server provide ability to pass *http.Server
 func Server(hs *http.Server) server.Option {
 	return server.SetOption(serverKey{}, hs)
 }
+
+type errorHandlerKey struct{}
+
+// ErrorHandler specifies handler for errors
+func ErrorHandler(fn func(ctx context.Context, s server.Handler, w http.ResponseWriter, r *http.Request, err error, status int)) server.Option {
+	return server.SetOption(errorHandlerKey{}, fn)
+}