Rework the Airbrake hook

Rework the Airbrake hook to:

a) change the interface so that the Airbrake credentials are stored in
an unexported struct, `airbrakeHook`, which is instantiated using the
`NewHook()` method

b) send log entries where no 'error' field is set to Airbrake, using the
`entry.Message` string as the message sent to Airbrake but continue to
allow the passing of error types using the 'error' field

Update the tests accordingly, assuring that the correct message is
received by the Airbrake server.

Also update the examples in the README, which would not have worked with
the previous implementation of the Airbrake hook.

README.md

@@ -82,7 +82,7 @@ func init() {
 
   // Use the Airbrake hook to report errors that have Error severity or above to
   // an exception tracker. You can create custom hooks, see the Hooks section.
-  log.AddHook(&logrus_airbrake.AirbrakeHook{})
+  log.AddHook(airbrake.NewHook("https://example.com", "xyz", "development"))
 
   // Output to stderr instead of stdout, could also be a file.
   log.SetOutput(os.Stderr)
@@ -211,7 +211,7 @@ import (
 )
 
 func init() {
-  log.AddHook(new(logrus_airbrake.AirbrakeHook))
+  log.AddHook(airbrake.NewHook("https://example.com", "xyz", "development"))
 
   hook, err := logrus_syslog.NewSyslogHook("udp", "localhost:514", syslog.LOG_INFO, "")
   if err != nil {

examples/hook/hook.go

@@ -3,21 +3,16 @@ package main
 import (
 	"github.com/Sirupsen/logrus"
 	"github.com/Sirupsen/logrus/hooks/airbrake"
-	"github.com/tobi/airbrake-go"
 )
 
 var log = logrus.New()
 
 func init() {
 	log.Formatter = new(logrus.TextFormatter) // default
-	log.Hooks.Add(new(logrus_airbrake.AirbrakeHook))
+	log.Hooks.Add(airbrake.NewHook("https://example.com", "xyz", "development"))
 }
 
 func main() {
-	airbrake.Endpoint = "https://exceptions.whatever.com/notifier_api/v2/notices.xml"
-	airbrake.ApiKey = "whatever"
-	airbrake.Environment = "production"
-
 	log.WithFields(logrus.Fields{
 		"animal": "walrus",
 		"size":   10,

hooks/airbrake/airbrake.go

@@ -1,51 +1,51 @@
 package airbrake
 
 import (
+	"errors"
+	"fmt"
+
 	"github.com/Sirupsen/logrus"
 	"github.com/tobi/airbrake-go"
 )
 
 // AirbrakeHook to send exceptions to an exception-tracking service compatible
-// with the Airbrake API. You must set:
-// * airbrake.Endpoint
-// * airbrake.ApiKey
-// * airbrake.Environment
-//
-// Before using this hook, to send an error. Entries that trigger an Error,
-// Fatal or Panic should now include an "error" field to send to Airbrake.
-type AirbrakeHook struct{}
+// with the Airbrake API.
+type airbrakeHook struct {
+	APIKey      string
+	Endpoint    string
+	Environment string
+}
 
-func (hook *AirbrakeHook) Fire(entry *logrus.Entry) error {
-	if entry.Data["error"] == nil {
-		entry.Logger.WithFields(logrus.Fields{
-			"source":   "airbrake",
-			"endpoint": airbrake.Endpoint,
-		}).Warn("Exceptions sent to Airbrake must have an 'error' key with the error")
-		return nil
+func NewHook(endpoint, apiKey, env string) *airbrakeHook {
+	return &airbrakeHook{
+		APIKey:      apiKey,
+		Endpoint:    endpoint,
+		Environment: env,
 	}
+}
 
+func (hook *airbrakeHook) Fire(entry *logrus.Entry) error {
+	airbrake.ApiKey = hook.APIKey
+	airbrake.Endpoint = hook.Endpoint
+	airbrake.Environment = hook.Environment
+
+	var notifyErr error
 	err, ok := entry.Data["error"].(error)
-	if !ok {
-		entry.Logger.WithFields(logrus.Fields{
-			"source":   "airbrake",
-			"endpoint": airbrake.Endpoint,
-		}).Warn("Exceptions sent to Airbrake must have an `error` key of type `error`")
-		return nil
+	if ok {
+		notifyErr = err
+	} else {
+		notifyErr = errors.New(entry.Message)
 	}
 
-	airErr := airbrake.Notify(err)
+	airErr := airbrake.Notify(notifyErr)
 	if airErr != nil {
-		entry.Logger.WithFields(logrus.Fields{
-			"source":   "airbrake",
-			"endpoint": airbrake.Endpoint,
-			"error":    airErr,
-		}).Warn("Failed to send error to Airbrake")
+		return fmt.Errorf("Failed to send error to Airbrake: %s", airErr)
 	}
 
 	return nil
 }
 
-func (hook *AirbrakeHook) Levels() []logrus.Level {
+func (hook *airbrakeHook) Levels() []logrus.Level {
 	return []logrus.Level{
 		logrus.ErrorLevel,
 		logrus.FatalLevel,

hooks/airbrake/airbrake_test.go

@@ -2,26 +2,123 @@ package airbrake
 
 import (
 	"encoding/xml"
-	"errors"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 	"time"
 
 	"github.com/Sirupsen/logrus"
-	"github.com/tobi/airbrake-go"
 )
 
 type notice struct {
-	Error struct {
+	Error NoticeError `xml:"error"`
+}
+type NoticeError struct {
+	Class   string `xml:"class"`
 	Message string `xml:"message"`
-	} `xml:"error"`
 }
 
-func TestNoticeReceived(t *testing.T) {
-	msg := make(chan string, 1)
-	expectedMsg := "foo"
+type customErr struct {
+	msg string
+}
 
+func (e *customErr) Error() string {
+	return e.msg
+}
+
+const (
+	testAPIKey    = "abcxyz"
+	testEnv       = "development"
+	expectedClass = "*airbrake.customErr"
+	expectedMsg   = "foo"
+	unintendedMsg = "Airbrake will not see this string"
+)
+
+var (
+	noticeError = make(chan NoticeError, 1)
+)
+
+// TestLogEntryMessageReceived checks if invoking Logrus' log.Error
+// method causes an XML payload containing the log entry message is received
+// by a HTTP server emulating an Airbrake-compatible endpoint.
+func TestLogEntryMessageReceived(t *testing.T) {
+	log := logrus.New()
+	ts := startAirbrakeServer(t)
+	defer ts.Close()
+
+	hook := NewHook(ts.URL, testAPIKey, "production")
+	log.Hooks.Add(hook)
+
+	log.Error(expectedMsg)
+
+	select {
+	case received := <-noticeError:
+		if received.Message != expectedMsg {
+			t.Errorf("Unexpected message received: %s", received.Message)
+		}
+	case <-time.After(time.Second):
+		t.Error("Timed out; no notice received by Airbrake API")
+	}
+}
+
+// TestLogEntryMessageReceived confirms that, when passing an error type using
+// logrus.Fields, a HTTP server emulating an Airbrake endpoint receives the
+// error message returned by the Error() method on the error interface
+// rather than the logrus.Entry.Message string.
+func TestLogEntryWithErrorReceived(t *testing.T) {
+	log := logrus.New()
+	ts := startAirbrakeServer(t)
+	defer ts.Close()
+
+	hook := NewHook(ts.URL, testAPIKey, "production")
+	log.Hooks.Add(hook)
+
+	log.WithFields(logrus.Fields{
+		"error": &customErr{expectedMsg},
+	}).Error(unintendedMsg)
+
+	select {
+	case received := <-noticeError:
+		if received.Message != expectedMsg {
+			t.Errorf("Unexpected message received: %s", received.Message)
+		}
+		if received.Class != expectedClass {
+			t.Errorf("Unexpected error class: %s", received.Class)
+		}
+	case <-time.After(time.Second):
+		t.Error("Timed out; no notice received by Airbrake API")
+	}
+}
+
+// TestLogEntryWithNonErrorTypeNotReceived confirms that, when passing a
+// non-error type using logrus.Fields, a HTTP server emulating an Airbrake
+// endpoint receives the logrus.Entry.Message string.
+//
+// Only error types are supported when setting the 'error' field using
+// logrus.WithFields().
+func TestLogEntryWithNonErrorTypeNotReceived(t *testing.T) {
+	log := logrus.New()
+	ts := startAirbrakeServer(t)
+	defer ts.Close()
+
+	hook := NewHook(ts.URL, testAPIKey, "production")
+	log.Hooks.Add(hook)
+
+	log.WithFields(logrus.Fields{
+		"error": expectedMsg,
+	}).Error(unintendedMsg)
+
+	select {
+	case received := <-noticeError:
+		if received.Message != unintendedMsg {
+			t.Errorf("Unexpected message received: %s", received.Message)
+		}
+	case <-time.After(time.Second):
+		t.Error("Timed out; no notice received by Airbrake API")
+	}
+}
+
+func startAirbrakeServer(t *testing.T) *httptest.Server {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		var notice notice
 		if err := xml.NewDecoder(r.Body).Decode(&notice); err != nil {
@@ -29,29 +126,8 @@ func TestNoticeReceived(t *testing.T) {
 		}
 		r.Body.Close()
 
-		msg <- notice.Error.Message
+		noticeError <- notice.Error
 	}))
-	defer ts.Close()
 
-	hook := &AirbrakeHook{}
-
-	airbrake.Environment = "production"
-	airbrake.Endpoint = ts.URL
-	airbrake.ApiKey = "foo"
-
-	log := logrus.New()
-	log.Hooks.Add(hook)
-
-	log.WithFields(logrus.Fields{
-		"error": errors.New(expectedMsg),
-	}).Error("Airbrake will not see this string")
-
-	select {
-	case received := <-msg:
-		if received != expectedMsg {
-			t.Errorf("Unexpected message received: %s", received)
-		}
-	case <-time.After(time.Second):
-		t.Error("Timed out; no notice received by Airbrake API")
-	}
+	return ts
 }