Merge pull request kubernetes#16 from fredbi/serve-nil-error

Completed test for ServeError with nil Error, as discussed in kubernetes#13

README.md

@@ -1,5 +1,8 @@
 # OpenAPI errors [![Build Status](https://travis-ci.org/go-openapi/errors.svg?branch=master)](https://travis-ci.org/go-openapi/errors) [![codecov](https://codecov.io/gh/go-openapi/errors/branch/master/graph/badge.svg)](https://codecov.io/gh/go-openapi/errors) [![Slack Status](https://slackin.goswagger.io/badge.svg)](https://slackin.goswagger.io)
 
-[![license](http://img.shields.io/badge/license-Apache%20v2-orange.svg)](https://raw.githubusercontent.com/go-openapi/errors/master/LICENSE) [![GoDoc](https://godoc.org/github.com/go-openapi/errors?status.svg)](http://godoc.org/github.com/go-openapi/errors) 
+[![license](http://img.shields.io/badge/license-Apache%20v2-orange.svg)](https://raw.githubusercontent.com/go-openapi/errors/master/LICENSE)
+[![GoDoc](https://godoc.org/github.com/go-openapi/errors?status.svg)](http://godoc.org/github.com/go-openapi/errors)
+[![GolangCI](https://golangci.com/badges/github.com/go-openapi/errors.svg)](https://golangci.com)
+[![Go Report Card](https://goreportcard.com/badge/github.com/go-openapi/errors)](https://goreportcard.com/report/github.com/go-openapi/errors)
 
-Shared errors used throughout the various libraries for the go-openapi toolkit 
+Shared errors and error interface used throughout the various libraries found in the go-openapi toolkit.

api.go

@@ -18,6 +18,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"reflect"
 	"strings"
 )
 
@@ -136,7 +137,8 @@ func ServeError(rw http.ResponseWriter, r *http.Request, err error) {
 			rw.Write(errorAsJSON(e))
 		}
 	case Error:
-		if e == nil {
+		value := reflect.ValueOf(e)
+		if value.Kind() == reflect.Ptr && value.IsNil() {
 			rw.WriteHeader(http.StatusInternalServerError)
 			rw.Write(errorAsJSON(New(http.StatusInternalServerError, "Unknown error")))
 			return

api_test.go

@@ -23,6 +23,10 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+type customError struct {
+	apiError
+}
+
 func TestServeError(t *testing.T) {
 	// method not allowed wins
 	// err abides by the Error interface
@@ -132,6 +136,12 @@ func TestServeError(t *testing.T) {
 	ServeError(recorder, nil, nil)
 	assert.Equal(t, http.StatusInternalServerError, recorder.Code)
 	assert.Equal(t, `{"code":500,"message":"Unknown error"}`, recorder.Body.String())
+
+	recorder = httptest.NewRecorder()
+	var z *customError
+	ServeError(recorder, nil, z)
+	assert.Equal(t, http.StatusInternalServerError, recorder.Code)
+	assert.Equal(t, `{"code":500,"message":"Unknown error"}`, recorder.Body.String())
 }
 
 func TestAPIErrors(t *testing.T) {