session: add deterministic map compare

This commit adds a deterministic comparison for the maps in sessions
during the KVDB to SQL migration.

Author: ViktorTigerstrom

session/sql_migration.go

@@ -10,9 +10,12 @@ import (
 	"sort"
 	"time"
 
+	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/davecgh/go-spew/spew"
+	"github.com/lightninglabs/lightning-node-connect/mailbox"
 	"github.com/lightninglabs/lightning-terminal/accounts"
 	"github.com/lightninglabs/lightning-terminal/db/sqlc"
+	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/sqldb"
 	"github.com/pmezard/go-difflib/difflib"
 	"go.etcd.io/bbolt"
@@ -25,6 +28,105 @@ var (
 		"original session")
 )
 
+// featureConfigEntry is a variant of a single session feature config, which
+// can be inserted into an array to be compared deterministically.
+type featureConfigEntry struct {
+	featureName string
+	config      []byte
+}
+
+// deterministicSession is a variant of the Session struct without any struct
+// methods, which represents the map in the Session as a list, so that it can be
+// deterministically sorted for comparison during the kvdb to SQL migration.
+type deterministicSession struct {
+	ID                ID
+	Label             string
+	State             State
+	Type              Type
+	Expiry            time.Time
+	CreatedAt         time.Time
+	RevokedAt         time.Time
+	ServerAddr        string
+	DevServer         bool
+	MacaroonRootKey   uint64
+	MacaroonRecipe    *MacaroonRecipe
+	PairingSecret     [mailbox.NumPassphraseEntropyBytes]byte
+	LocalPrivateKey   *btcec.PrivateKey
+	LocalPublicKey    *btcec.PublicKey
+	RemotePublicKey   *btcec.PublicKey
+	FeatureConfig     []*featureConfigEntry
+	WithPrivacyMapper bool
+	PrivacyFlags      PrivacyFlags
+
+	// GroupID is the Session ID of the very first Session in the linked
+	// group of sessions. If this is the very first session in the group
+	// then this will be the same as ID.
+	GroupID ID
+
+	// AccountID is an optional account that the session has been linked to.
+	AccountID fn.Option[accounts.AccountID]
+}
+
+// newDeterministicSession creates a deterministicSession from a Session struct.
+// This is used to compare the session in a deterministic way during the
+// migration from the KV database to the SQL database.
+func newDeterministicSession(sess *Session) *deterministicSession {
+	var featuresConfig []*featureConfigEntry
+
+	// If a session has a feature config set, we'll convert it to an array
+	// so that we can sort it and compare it deterministically.
+	if sess.FeatureConfig != nil {
+		sessFC := *sess.FeatureConfig
+		featuresConfig = make([]*featureConfigEntry, len(sessFC))
+
+		i := 0
+		for featureName, config := range sessFC {
+			featuresConfig[i] = &featureConfigEntry{
+				featureName: featureName,
+				config:      config,
+			}
+
+			i++
+		}
+
+		// Sort the feature config entries by their feature name, and
+		// by their config bytes if the feature names are the same.
+		sort.Slice(featuresConfig, func(i, j int) bool {
+			iC := featuresConfig[i]
+			jC := featuresConfig[j]
+
+			if iC.featureName == jC.featureName {
+				return bytes.Compare(iC.config, jC.config) < 0
+			}
+
+			return iC.featureName < jC.featureName
+		})
+	}
+
+	return &deterministicSession{
+		ID:                sess.ID,
+		Label:             sess.Label,
+		State:             sess.State,
+		Type:              sess.Type,
+		Expiry:            sess.Expiry,
+		CreatedAt:         sess.CreatedAt,
+		RevokedAt:         sess.RevokedAt,
+		ServerAddr:        sess.ServerAddr,
+		DevServer:         sess.DevServer,
+		MacaroonRootKey:   sess.MacaroonRootKey,
+		PairingSecret:     sess.PairingSecret,
+		LocalPrivateKey:   sess.LocalPrivateKey,
+		LocalPublicKey:    sess.LocalPublicKey,
+		RemotePublicKey:   sess.RemotePublicKey,
+		GroupID:           sess.GroupID,
+		AccountID:         sess.AccountID,
+		PrivacyFlags:      sess.PrivacyFlags,
+		MacaroonRecipe:    sess.MacaroonRecipe,
+		WithPrivacyMapper: sess.WithPrivacyMapper,
+		FeatureConfig:     featuresConfig,
+	}
+}
+
 // MigrateSessionStoreToSQL runs the migration of all sessions from the KV
 // database to the SQL database. The migration is done in a single transaction
 // to ensure that all sessions are migrated or none at all.
@@ -149,13 +251,16 @@ func migrateSessionsToSQLAndValidate(ctx context.Context,
 		overrideSessionTimeZone(migratedSession)
 		overrideMacaroonRecipe(kvSession, migratedSession)
 
-		if !reflect.DeepEqual(kvSession, migratedSession) {
+		dKvSession := newDeterministicSession(kvSession)
+		dMigratedSession := newDeterministicSession(migratedSession)
+
+		if !reflect.DeepEqual(dKvSession, dMigratedSession) {
 			diff := difflib.UnifiedDiff{
 				A: difflib.SplitLines(
-					spew.Sdump(kvSession),
+					spew.Sdump(dKvSession),
 				),
 				B: difflib.SplitLines(
-					spew.Sdump(migratedSession),
+					spew.Sdump(dMigratedSession),
 				),
 				FromFile: "Expected",
 				FromDate: "",
@@ -166,7 +271,7 @@ func migrateSessionsToSQLAndValidate(ctx context.Context,
 			diffText, _ := difflib.GetUnifiedDiffString(diff)
 
 			return fmt.Errorf("%w: %v.\n%v", ErrMigrationMismatch,
-				kvSession.ID, diffText)
+				dKvSession.ID, diffText)
 		}
 	}