Expose the Err helper from the global logger

log/log.go

@@ -37,6 +37,14 @@ func Hook(h zerolog.Hook) zerolog.Logger {
 	return Logger.Hook(h)
 }
 
+// Err starts a new message with error level with err as a field if not nil or
+// with info level if err is nil.
+//
+// You must call Msg on the returned event in order to send the event.
+func Err(err error) *zerolog.Event {
+	return Logger.Err(err)
+}
+
 // Trace starts a new message with trace level.
 //
 // You must call Msg on the returned event in order to send the event.

log/log_example_test.go

@@ -54,6 +54,17 @@ func ExampleLog() {
 	// Output: {"time":1199811905,"message":"hello world"}
 }
 
+// Example of a conditional level based on the presence of an error.
+func ExampleErr() {
+	setup()
+	err := errors.New("some error")
+	log.Err(err).Msg("hello world")
+	log.Err(nil).Msg("hello world")
+
+	// Output: {"level":"error","error":"some error","time":1199811905,"message":"hello world"}
+	// {"level":"info","time":1199811905,"message":"hello world"}
+}
+
 // Example of a log at a particular "level" (in this case, "trace")
 func ExampleTrace() {
 	setup()