fix(GODT-1749): Convert panics to errors

Converted most panics that can be handled properly as an error to error.

internal/backend/mailbox_fetch.go

@@ -137,7 +137,7 @@ func (m *Mailbox) fetchKeyword(msg *snapMsg, message *ent.Message, keyword proto
 		return response.ItemUID(msg.UID), nil
 
 	default:
-		panic("bad keyword")
+		return nil, fmt.Errorf("bad fetch keyword")
 	}
 }
 
@@ -202,7 +202,12 @@ func (m *Mailbox) fetchBodyLiteral(body *proto.FetchBody, literal []byte) ([]byt
 			return nil, "", err
 		}
 
-		return b, renderSection(section.Section), nil
+		renderedSection, err := renderSection(section.Section)
+		if err != nil {
+			return nil, "", err
+		}
+
+		return b, renderedSection, nil
 
 	default:
 		return literal, "", nil
@@ -256,15 +261,15 @@ func (m *Mailbox) fetchBodySection(section *proto.BodySection, literal []byte) (
 			return root.Header(), nil
 
 		default:
-			panic("bad keyword")
+			return nil, fmt.Errorf("bad section keyword")
 		}
 
 	default:
 		return root.Body(), nil
 	}
 }
 
-func renderSection(section *proto.BodySection) string {
+func renderSection(section *proto.BodySection) (string, error) {
 	var res []string
 
 	if len(section.Parts) > 0 {
@@ -290,11 +295,11 @@ func renderSection(section *proto.BodySection) string {
 			res = append(res, "MIME")
 
 		default:
-			panic("bad keyword")
+			return "", fmt.Errorf("bad body section keyword")
 		}
 	}
 
-	return strings.ToUpper(strings.Join(res, "."))
+	return strings.ToUpper(strings.Join(res, ".")), nil
 }
 
 func renderParts(sectionParts []int) string {

internal/backend/mailbox_search.go

@@ -3,6 +3,7 @@ package backend
 import (
 	"bytes"
 	"context"
+	"fmt"
 	"net/mail"
 	"strings"
 	"time"
@@ -157,7 +158,7 @@ func (m *Mailbox) matchSearchKey(ctx context.Context, candidates []*snapMsg, key
 		return m.matchSearchKeyList(ctx, candidates, key, decoder)
 
 	default:
-		panic("bad keyword")
+		return nil, fmt.Errorf("bad search keyword")
 	}
 }
 

internal/backend/seqset.go

@@ -1,8 +1,11 @@
 package backend
 
-import "github.com/ProtonMail/gluon/internal/parser/proto"
+import (
+	"fmt"
+	"github.com/ProtonMail/gluon/internal/parser/proto"
+)
 
-func toSeqSet(set *proto.SequenceSet) [][]string {
+func toSeqSet(set *proto.SequenceSet) ([][]string, error) {
 	var seqRanges [][]string
 
 	for _, item := range set.GetItems() {
@@ -16,11 +19,11 @@ func toSeqSet(set *proto.SequenceSet) [][]string {
 			seqRange = append(seqRange, item.Range.GetBegin(), item.Range.GetEnd())
 
 		default:
-			panic("bad sequence range")
+			return nil, fmt.Errorf("bad sequence range")
 		}
 
 		seqRanges = append(seqRanges, seqRange)
 	}
 
-	return seqRanges
+	return seqRanges, nil
 }

internal/backend/snapshot.go

@@ -110,7 +110,12 @@ func (snap *snapshot) getMessagesInRange(ctx context.Context, seq *proto.Sequenc
 func (snap *snapshot) getMessagesInSeqRange(seq *proto.SequenceSet) ([]*snapMsg, error) {
 	var res []*snapMsg
 
-	for _, seqRange := range toSeqSet(seq) {
+	seqSet, err := toSeqSet(seq)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, seqRange := range seqSet {
 		switch len(seqRange) {
 		case 1:
 			seq, err := snap.resolveSeq(seqRange[0])
@@ -138,7 +143,7 @@ func (snap *snapshot) getMessagesInSeqRange(seq *proto.SequenceSet) ([]*snapMsg,
 			res = append(res, snap.seqRange(begin, end)...)
 
 		default:
-			panic("bad sequence range")
+			return nil, fmt.Errorf("bad sequence range")
 		}
 	}
 
@@ -153,7 +158,12 @@ func (snap *snapshot) getMessagesInUIDRange(seq *proto.SequenceSet) ([]*snapMsg,
 		return nil, nil
 	}
 
-	for _, uidRange := range toSeqSet(seq) {
+	seqSet, err := toSeqSet(seq)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, uidRange := range seqSet {
 		switch len(uidRange) {
 		case 1:
 			uid, err := snap.resolveUID(uidRange[0])
@@ -181,7 +191,7 @@ func (snap *snapshot) getMessagesInUIDRange(seq *proto.SequenceSet) ([]*snapMsg,
 			res = append(res, snap.uidRange(begin, end)...)
 
 		default:
-			panic("bad sequence range")
+			return nil, fmt.Errorf("bad sequence range")
 		}
 	}
 

internal/backend/state_actions.go

@@ -354,7 +354,7 @@ func (state *State) actionRemoveMessageFlags(
 
 func (state *State) actionSetMessageFlags(ctx context.Context, tx *ent.Tx, messageIDs []MessageIDPair, setFlags imap.FlagSet) error {
 	if setFlags.Contains(imap.FlagRecent) {
-		panic("recent flag is read-only")
+		return fmt.Errorf("recent flag is read-only")
 	}
 
 	curFlags := make(map[imap.MessageID]imap.FlagSet)

internal/backend/state_updates.go

@@ -2,6 +2,7 @@ package backend
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/ProtonMail/gluon/imap"
 	"github.com/ProtonMail/gluon/internal/backend/ent"
@@ -11,7 +12,7 @@ import (
 // applyMessageFlagsAdded adds the flags to the given messages.
 func (state *State) applyMessageFlagsAdded(ctx context.Context, tx *ent.Tx, messageIDs []imap.InternalMessageID, addFlags imap.FlagSet) error {
 	if addFlags.Contains(imap.FlagRecent) {
-		panic("the recent flag is read-only")
+		return fmt.Errorf("the recent flag is read-only")
 	}
 
 	client := tx.Client()
@@ -72,7 +73,7 @@ func (state *State) applyMessageFlagsAdded(ctx context.Context, tx *ent.Tx, mess
 // applyMessageFlagsRemoved removes the flags from the given messages.
 func (state *State) applyMessageFlagsRemoved(ctx context.Context, tx *ent.Tx, messageIDs []imap.InternalMessageID, remFlags imap.FlagSet) error {
 	if remFlags.Contains(imap.FlagRecent) {
-		panic("the recent flag is read-only")
+		return fmt.Errorf("the recent flag is read-only")
 	}
 
 	client := tx.Client()
@@ -139,7 +140,7 @@ func (state *State) applyMessageFlagsRemoved(ctx context.Context, tx *ent.Tx, me
 // applyMessageFlagsSet sets the flags of the given messages.
 func (state *State) applyMessageFlagsSet(ctx context.Context, tx *ent.Tx, messageIDs []imap.InternalMessageID, setFlags imap.FlagSet) error {
 	if setFlags.Contains(imap.FlagRecent) {
-		panic("the recent flag is read-only")
+		return fmt.Errorf("the recent flag is read-only")
 	}
 
 	if err := DBSetDeletedFlag(ctx, tx, state.snap.mboxID.InternalID, messageIDs, setFlags.Contains(imap.FlagDeleted)); err != nil {

internal/backend/user_state.go

@@ -49,7 +49,7 @@ func (user *user) removeState(ctx context.Context, stateID int) error {
 
 		state, ok := user.states[stateID]
 		if !ok {
-			panic("no such state")
+			return nil, fmt.Errorf("no such state")
 		}
 
 		messageIDs = xslices.Filter(messageIDs, func(messageID imap.InternalMessageID) bool {

internal/backend/user_updates.go

@@ -49,7 +49,7 @@ func (user *user) apply(ctx context.Context, update imap.Update) error {
 		return user.applyMessageDeleted(ctx, update)
 
 	default:
-		panic("bad update")
+		return fmt.Errorf("bad update")
 	}
 }