wip: fix skylabify unknown id crash?

cmd/skylabify/skylabify.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/kschamplin/gotelem/skylab"
 	"github.com/urfave/cli/v2"
+	"golang.org/x/exp/slog"
 )
 
 // this command can be used to decode candump logs and dump json output.
@@ -112,7 +113,11 @@ func run(ctx *cli.Context) (err error) {
 
 		// parse the data []byte to a skylab packet
 		cd.Data, err = skylab.FromCanFrame(uint32(cd.Id), rawData)
-		if err != nil {
+		var idErr *skylab.UnknownIdError
+		if errors.As(err, &idErr) {
+			// unknown id
+			slog.Info("unknown id", "err", err)
+		} else if err != nil {
 			return err
 		}
 

skylab/skylab.go

@@ -3,6 +3,7 @@ package skylab
 import (
 	"encoding/binary"
 	"encoding/json"
+	"fmt"
 	"math"
 
 	// this is needed so that we can run make_skylab.go
@@ -162,3 +163,12 @@ func (e *BusEvent) UnmarshalMsg(b []byte) ([]byte, error) {
 
 // we need to be able to parse the JSON as well.  this is done using the
 // generator since we can use the switch/case thing since it's the fastest
+
+
+type UnknownIdError struct {
+	id uint64
+}
+
+func (e *UnknownIdError) Error() string {
+	return fmt.Sprintf("unknown id: %x", e.id)
+}

skylab/templates/golang.go.tmpl

@@ -48,7 +48,7 @@ type {{$structName}} struct {
 func (p *{{$structName}}) CANId() (uint32, error) {
 {{- if .Repeat }}
 	if p.Idx >= {{.Repeat}} {
-		return 0, errors.New("invalid packet index")
+		return 0, &UnknownIdError{ {{ printf "0x%X" .Id }} }
 	}
 	return {{ printf "0x%X" .Id }} + p.Idx, nil
 {{- else }}
@@ -114,7 +114,7 @@ var idMap = map[uint32]bool{
 // If the CAN ID is unknown, it will return an error.
 func FromCanFrame(id uint32, data []byte) (Packet, error) {
 	if !idMap[id] {
-		return nil, errors.New("unknown id")
+		return nil, &UnknownIdError{ id }
 	}
 	switch id {
 {{- range $p := .Packets }}
@@ -167,4 +167,4 @@ func FromJson (id uint32, raw []byte) (Packet, error) {
 
 // The json representation that was used to generate this data.
 // can be used to share the parsing data for i.e dynamic python gui.
-const SkylabDefinitions = `{{json . | printf "%s" }}`
+const SkylabDefinitions = `{{json . | printf "%s" }}`