fix: return empty array not null when there are no sessions (#2548)

Author: kszafran

persistence/sql/persister_session.go

@@ -47,7 +47,7 @@ func (p *Persister) ListSessionsByIdentity(ctx context.Context, iID uuid.UUID, a
 	ctx, span := p.r.Tracer(ctx).Tracer().Start(ctx, "persistence.sql.ListSessionsByIdentity")
 	defer span.End()
 
-	var s []*session.Session
+	s := make([]*session.Session, 0)
 	nid := corp.ContextualizeNID(ctx, p.nid)
 
 	if err := p.Transaction(ctx, func(ctx context.Context, c *pop.Connection) error {

session/handler_test.go

@@ -32,6 +32,7 @@ import (
 	"github.com/ory/kratos/internal/testhelpers"
 	. "github.com/ory/kratos/session"
 	"github.com/ory/kratos/x"
+	"github.com/ory/x/ioutilx"
 	"github.com/ory/x/urlx"
 )
 
@@ -441,10 +442,7 @@ func TestHandlerAdminSessionManagement(t *testing.T) {
 			res, err := client.Do(req)
 			require.NoError(t, err)
 			assert.Equal(t, http.StatusOK, res.StatusCode)
-
-			var sessions []Session
-			require.NoError(t, json.NewDecoder(res.Body).Decode(&sessions))
-			assert.Len(t, sessions, 0)
+			assert.JSONEq(t, "[]", string(ioutilx.MustReadAll(res.Body)))
 		})
 	})