Event ingestion: Mechanism.Type is missing

[ioxenus]

In Sentry's docs on event payloads - exception mechanism it says that the "type" attribute is required.

However, sentry-go v0.29.1 sometimes sends an event that has mechanism included, but the type is omitted.

Reproduction:

mkdir issue350
cd issue350
go mod init issue350
go get github.com/getsentry/[email protected]
touch test.txt
chmod 407 test.txt

main.go:

package main

import (
	"os"
	"time"

	sentry "github.com/getsentry/sentry-go"
)

func main() {
	sentry.Init(sentry.ClientOptions{
		Dsn:              "https://[email protected]/1",
		Debug:            true,
	})

	defer func() {
		if err := recover(); err != nil {
			sentry.CurrentHub().Recover(err)
			sentry.Flush(time.Second * 5)
		}
	}()

	if err := os.WriteFile("test.txt", []byte("foobar"), 0666); err != nil {
		panic(err)
	}
}

It yields such a JSON payload:

"exception": [
    {
        "type": "syscall.Errno",
        "value": "permission denied",
        "mechanism":{
            "exception_id": 0, 
            "is_exception_group": true
        }
    },
    {
        "type":"*fs.PathError",
        "value":"open test.txt: permission denied",
        "stacktrace": ...
        ...
    }
]

Maybe it'd be better to remove json:"type,omitempty" from Mechanism.Type?

————

I solved that myself by adding such a BeforeSend to sentry.ClientOptions:

sentry_err := sentry.Init(sentry.ClientOptions{
	Dsn: "https://[email protected]/1",
	Debug: true,

	BeforeSend: func(event *sentry.Event, hint *sentry.EventHint) *sentry.Event {
		for _, x := range event.Exception {
			if x.Mechanism != nil && x.Mechanism.Type == "" {
				x.Mechanism.Type = "foobar"
			}
		}
		return event
	},
})

(can also be done with sentry.ConfigureScope and scope.AddEventProcessor)

[ribice]

You are right, this Type is never set. Currently IsExceptionGroup, ExceptionID and ParentID are used in Mechanism. I'll see what can we set for Type.

[ribice]

@cleptric I inspected other SDKs for this - for example in the javascript one it either sets this type as generic, angular, cloudflare.

The easiest way to resolve it would be to set it to generic, or copy the same Type from Exception (which may serve no purpose, but might be better than generic?).

[cleptric]

Just using generic is fine.