feat: HTTPError.WithFields (#326)

* feat: HTTPError.WithFields

* fix: exclude from json

* fix: add test

Author: Skn0tt

router/errors.go

@@ -8,16 +8,18 @@ import (
 	"github.com/bugsnag/bugsnag-go/v2"
 	"github.com/netlify/netlify-commons/metriks"
 	"github.com/netlify/netlify-commons/tracing"
+	"github.com/sirupsen/logrus"
 )
 
 // HTTPError is an error with a message and an HTTP status code.
 type HTTPError struct {
-	Code            int         `json:"code"`
-	Message         string      `json:"msg"`
-	JSON            interface{} `json:"json,omitempty"`
-	InternalError   error       `json:"-"`
-	InternalMessage string      `json:"-"`
-	ErrorID         string      `json:"error_id,omitempty"`
+	Code            int           `json:"code"`
+	Message         string        `json:"msg"`
+	JSON            interface{}   `json:"json,omitempty"`
+	InternalError   error         `json:"-"`
+	InternalMessage string        `json:"-"`
+	ErrorID         string        `json:"error_id,omitempty"`
+	Fields          logrus.Fields `json:"-"`
 }
 
 // BadRequestError creates a 400 HTTP error
@@ -79,10 +81,25 @@ func (e *HTTPError) WithInternalMessage(fmtString string, args ...interface{}) *
 	return e
 }
 
+// WithFields will add fields to an error message
+func (e *HTTPError) WithFields(fields logrus.Fields) *HTTPError {
+	for key, value := range fields {
+		e.Fields[key] = value
+	}
+	return e
+}
+
+// WithFields will add fields to an error message
+func (e *HTTPError) WithField(key string, value interface{}) *HTTPError {
+	e.Fields[key] = value
+	return e
+}
+
 func httpError(code int, fmtString string, args ...interface{}) *HTTPError {
 	return &HTTPError{
 		Code:    code,
 		Message: fmt.Sprintf(fmtString, args...),
+		Fields:  make(logrus.Fields),
 	}
 }
 
@@ -102,6 +119,8 @@ func HandleError(err error, w http.ResponseWriter, r *http.Request) {
 
 	switch e := err.(type) {
 	case *HTTPError:
+		log = log.WithFields(e.Fields)
+
 		e.ErrorID = errorID
 		if e.Code >= http.StatusInternalServerError {
 			notifyBugsnag = true

router/errors_test.go

@@ -122,6 +122,36 @@ func TestHandleError_HTTPError(t *testing.T) {
 	assert.Equal(t, "internal server error: "+httpErr.InternalMessage, loggerOutput.AllEntries()[0].Message)
 }
 
+func TestHandleError_HttpErrorWithFields(t *testing.T) {
+	logger, loggerOutput := test.NewNullLogger()
+	recorder := httptest.NewRecorder()
+	w, r, _ := tracing.NewTracer(
+		recorder,
+		httptest.NewRequest(http.MethodGet, "/", nil),
+		logger,
+		"test",
+		"test",
+	)
+
+	httpErr := httpError(http.StatusInternalServerError, http.StatusText(http.StatusInternalServerError))
+
+	httpErr.WithFields(map[string]interface{}{
+		"a": "1",
+		"b": "2",
+	})
+
+	httpErr.WithField("c", "3")
+	httpErr.WithField("a", "0")
+
+	HandleError(httpErr, w, r)
+
+	require.Len(t, loggerOutput.AllEntries(), 1)
+	entry := loggerOutput.LastEntry()
+	assert.Equal(t, entry.Data["a"], "0")
+	assert.Equal(t, entry.Data["b"], "2")
+	assert.Equal(t, entry.Data["c"], "3")
+}
+
 func TestHandleError_NoLogForNormalErrors(t *testing.T) {
 	logger, loggerOutput := test.NewNullLogger()
 	recorder := httptest.NewRecorder()