test: add a panic catcher test

internal/catch/catch_test.go

@@ -0,0 +1,28 @@
+package catch
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestCatch(t *testing.T) {
+	buf := new(bytes.Buffer)
+
+	oldPanicWriter := panicWriter
+	t.Cleanup(func() { panicWriter = oldPanicWriter })
+	panicWriter = buf
+
+	panicAndCatch := func() (err error) {
+		defer func() { HandlePanic(recover(), &err, "somewhere") }()
+
+		panic("here")
+	}
+
+	err := panicAndCatch()
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "panic in somewhere: here")
+
+	require.Contains(t, buf.String(), "caught panic: here")
+}