make ServerOption panic messages more clear. (#1194)
ServerOption panics when fields that have been manually set are
subsequently set again. The message verbiage of `X has been set` is
unclear since `has been set` without an adverb like `already` does not
correctly convey that the fields are set-once and were previously set.
At the worst, the original verbiage `X has been set` could imply that
the new value would have been acceptable but another error occurred.
We discovered this while conducting a code survey for implementing
extensible stubs and uniform inbound interception API.
diff --git a/server.go b/server.go
index 8bae298..0d17e78 100644
--- a/server.go
+++ b/server.go
@@ -210,7 +210,7 @@
func UnaryInterceptor(i UnaryServerInterceptor) ServerOption {
return func(o *options) {
if o.unaryInt != nil {
- panic("The unary server interceptor has been set.")
+ panic("The unary server interceptor was already set and may not be reset.")
}
o.unaryInt = i
}
@@ -221,7 +221,7 @@
func StreamInterceptor(i StreamServerInterceptor) ServerOption {
return func(o *options) {
if o.streamInt != nil {
- panic("The stream server interceptor has been set.")
+ panic("The stream server interceptor was already set and may not be reset.")
}
o.streamInt = i
}
@@ -232,7 +232,7 @@
func InTapHandle(h tap.ServerInHandle) ServerOption {
return func(o *options) {
if o.inTapHandle != nil {
- panic("The tap handle has been set.")
+ panic("The tap handle was already set and may not be reset.")
}
o.inTapHandle = h
}
