From 2100e2ff7cac86f8bdb93ae424dfe026820fb6cd Mon Sep 17 00:00:00 2001
From: Michal Horejsek <horejsek@protonmail.com>
Date: Tue, 1 Dec 2020 15:13:16 +0100
Subject: [PATCH] Enhanced sentry reporting

---
 internal/cmd/main.go      |  6 ++++--
 pkg/sentry/report.go      | 40 +++++++++++++++++++++++++++++++++---
 pkg/sentry/report_test.go | 43 +++++++++++++++++++++++++++++++++++++++
 unreleased.md             |  1 +
 4 files changed, 85 insertions(+), 5 deletions(-)
 create mode 100644 pkg/sentry/report_test.go

diff --git a/internal/cmd/main.go b/internal/cmd/main.go
index fa15636d..d34fb255 100644
--- a/internal/cmd/main.go
+++ b/internal/cmd/main.go
@@ -22,6 +22,7 @@ import (
 	"runtime"
 
 	"github.com/ProtonMail/proton-bridge/pkg/constants"
+	pkgSentry "github.com/ProtonMail/proton-bridge/pkg/sentry"
 	"github.com/getsentry/sentry-go"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
@@ -52,8 +53,9 @@ var (
 // Main sets up Sentry, filters out unwanted args, creates app and runs it.
 func Main(appName, usage string, extraFlags []cli.Flag, run func(*cli.Context) error) {
 	err := sentry.Init(sentry.ClientOptions{
-		Dsn:     constants.DSNSentry,
-		Release: constants.Revision,
+		Dsn:        constants.DSNSentry,
+		Release:    constants.Revision,
+		BeforeSend: pkgSentry.EnhanceSentryEvent,
 	})
 
 	sentry.ConfigureScope(func(scope *sentry.Scope) {
diff --git a/pkg/sentry/report.go b/pkg/sentry/report.go
index cd967584..f447fda6 100644
--- a/pkg/sentry/report.go
+++ b/pkg/sentry/report.go
@@ -19,13 +19,19 @@ package sentry
 
 import (
 	"errors"
+	"regexp"
 	"runtime"
+	"strings"
 	"time"
 
 	"github.com/getsentry/sentry-go"
 	log "github.com/sirupsen/logrus"
 )
 
+var (
+	isPanicHandlerRegexp = regexp.MustCompile(`^ReportSentryCrash|^(\(\*PanicHandler\)\.)?HandlePanic`) //nolint[gochecknoglobals]
+)
+
 // ReportSentryCrash reports a sentry crash.
 func ReportSentryCrash(clientID, appVersion, userAgent string, reportErr error) (err error) {
 	if reportErr == nil {
@@ -40,16 +46,44 @@ func ReportSentryCrash(clientID, appVersion, userAgent string, reportErr error)
 		"UserID":    "",
 	}
 
+	var reportID string
 	sentry.WithScope(func(scope *sentry.Scope) {
 		scope.SetTags(tags)
-		sentry.CaptureException(reportErr)
+		eventID := sentry.CaptureException(reportErr)
+		if eventID != nil {
+			reportID = string(*eventID)
+		}
 	})
 
 	if !sentry.Flush(time.Second * 10) {
-		log.WithField("error", reportErr).Error("failed to report sentry error")
+		log.WithField("error", reportErr).Error("Failed to report sentry error")
 		return errors.New("failed to report sentry error")
 	}
 
-	log.WithField("error", reportErr).Warn("reported sentry error")
+	log.WithField("error", reportErr).WithField("id", reportID).Warn("Sentry error reported")
 	return
 }
+
+// EnhanceSentryEvent swaps type with value and removes panic handlers from the stacktrace.
+func EnhanceSentryEvent(event *sentry.Event, hint *sentry.EventHint) *sentry.Event {
+	for idx, exception := range event.Exception {
+		exception.Type, exception.Value = exception.Value, exception.Type
+		if exception.Stacktrace != nil {
+			exception.Stacktrace.Frames = filterOutPanicHandlers(exception.Stacktrace.Frames)
+		}
+		event.Exception[idx] = exception
+	}
+	return event
+}
+
+func filterOutPanicHandlers(frames []sentry.Frame) []sentry.Frame {
+	idx := 0
+	for _, frame := range frames {
+		if strings.HasPrefix(frame.Module, "github.com/ProtonMail/proton-bridge") &&
+			isPanicHandlerRegexp.MatchString(frame.Function) {
+			break
+		}
+		idx++
+	}
+	return frames[:idx]
+}
diff --git a/pkg/sentry/report_test.go b/pkg/sentry/report_test.go
new file mode 100644
index 00000000..a473e063
--- /dev/null
+++ b/pkg/sentry/report_test.go
@@ -0,0 +1,43 @@
+// Copyright (c) 2020 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package sentry
+
+import (
+	"testing"
+
+	r "github.com/stretchr/testify/require"
+
+	"github.com/getsentry/sentry-go"
+)
+
+func TestFilterOutPanicHandlers(t *testing.T) {
+	frames := []sentry.Frame{
+		{Module: "github.com/ProtonMail/proton-bridge/internal/cmd", Function: "main"},
+		{Module: "github.com/urfave/cli", Function: "(*App).Run"},
+		{Module: "github.com/ProtonMail/proton-bridge/internal/cmd", Function: "RegisterHandlePanic"},
+		{Module: "github.com/ProtonMail/pkg", Function: "HandlePanic"},
+		{Module: "main", Function: "run"},
+		{Module: "github.com/ProtonMail/proton-bridge/pkg/config", Function: "(*PanicHandler).HandlePanic"},
+		{Module: "github.com/ProtonMail/proton-bridge/pkg/config", Function: "HandlePanic"},
+		{Module: "github.com/ProtonMail/proton-bridge/pkg/sentry", Function: "ReportSentryCrash"},
+		{Module: "github.com/ProtonMail/proton-bridge/pkg/sentry", Function: "ReportSentryCrash.func1"},
+	}
+
+	gotFrames := filterOutPanicHandlers(frames)
+	r.Equal(t, frames[:5], gotFrames)
+}
diff --git a/unreleased.md b/unreleased.md
index 670b14d1..214e18d0 100644
--- a/unreleased.md
+++ b/unreleased.md
@@ -8,6 +8,7 @@ Changelog [format](http://keepachangelog.com/en/1.0.0/)
 
 ### Changed
 * GODT-893 Bump go-rfc5322 dependency to v0.2.1 to properly detect syntax errors during parsing.
+* GODT-892 Swap type and value from sentry exception and cut panic handlers from the traceback.
 
 ### Removed
 * GODT-651 Build creates proper binary names.