Fail tests if unhandled panics happened.

We normally recover from those situations, printing stack traces instead of
crashing the program. But during tests, we're not looking at the prometheus
metrics or all the output. Without these checks, such panics could go
unnoticed. Seems like a reasonable thing to add, unhandled panics haven't been
encountered in tests.

dmarcdb/main_test.go

@@ -0,0 +1,17 @@
+package dmarcdb
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

http/main_test.go

@@ -0,0 +1,17 @@
+package http
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

imapserver/main_test.go

@@ -0,0 +1,17 @@
+package imapserver
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

main_test.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

metrics/panic.go

@@ -1,6 +1,8 @@
 package metrics
 
 import (
+	"sync/atomic"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 )
@@ -72,6 +74,9 @@ func init() {
 	}
 }
 
+var Panics atomic.Int64
+
 func PanicInc(name Panic) {
+	Panics.Add(1)
 	metricPanic.WithLabelValues(string(name)).Inc()
 }

mtasts/main_test.go

@@ -0,0 +1,17 @@
+package mtasts
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

mtastsdb/main_test.go

@@ -0,0 +1,17 @@
+package mtastsdb
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

queue/main_test.go

@@ -0,0 +1,17 @@
+package queue
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

smtpserver/main_test.go

@@ -0,0 +1,17 @@
+package smtpserver
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

store/main_test.go

@@ -0,0 +1,17 @@
+package store
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

tlsrptsend/main_test.go

@@ -0,0 +1,17 @@
+package tlsrptsend
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

webaccount/main_test.go

@@ -0,0 +1,17 @@
+package webaccount
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

webadmin/main_test.go

@@ -0,0 +1,17 @@
+package webadmin
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

webapisrv/main_test.go

@@ -0,0 +1,17 @@
+package webapisrv
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}

webmail/main_test.go

@@ -0,0 +1,17 @@
+package webmail
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mjl-/mox/metrics"
+)
+
+func TestMain(m *testing.M) {
+	m.Run()
+	if metrics.Panics.Load() > 0 {
+		fmt.Println("unhandled panics encountered")
+		os.Exit(2)
+	}
+}