fix: keep existing privileges when User.Added is processed late (#331)

client_test.go

@@ -12,6 +12,7 @@ import (
 	goamqp "codeberg.org/messaging/go-messaging-amqp"
 	spec "codeberg.org/messaging/messaging"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestPrivilegeHandler_Process_InvalidType(t *testing.T) {
@@ -91,6 +92,50 @@ func TestPrivilegeHandler_Process_UserAdded_And_UserRemoved(t *testing.T) {
 	assert.Empty(t, companies)
 }
 
+func TestPrivilegeHandler_Process_UserAdded_Keeps_Existing_Privileges(t *testing.T) {
+	// Each routing key has its own transient queue, so Privilege.Added can be
+	// processed before the User.Added published before it. The privilege must
+	// survive either order: nothing re-reads it until the next Fetch at start.
+	userAdded := &UserAdded{Email: "jim@example.org", CompanyID: "abc-123"}
+	privilegeAdded := &PrivilegeAdded{Email: "jim@example.org", CompanyID: "abc-123", Privilege: PrivilegeAdmin}
+	for name, order := range map[string][]any{
+		"user added first":      {userAdded, privilegeAdded},
+		"privilege added first": {privilegeAdded, userAdded},
+	} {
+		t.Run(name, func(t *testing.T) {
+			handler := New(WithBaseURL("base"))
+			for _, event := range order {
+				require.NoError(t, handler.Process(event))
+			}
+
+			assert.True(t, handler.IsAllowed("jim@example.org", "abc-123", func(privileges CompanyPrivileges) bool {
+				return privileges.Admin
+			}))
+		})
+	}
+}
+
+func TestPrivilegeHandler_Process_UserAdded_After_UserRemoved_Starts_Empty(t *testing.T) {
+	handler := New(WithBaseURL("base"))
+
+	assert.NoError(t, handler.Process(&UserAdded{Email: "jim@example.org", CompanyID: "abc-123"}))
+	assert.NoError(t, handler.Process(&PrivilegeAdded{
+		Email:     "jim@example.org",
+		CompanyID: "abc-123",
+		Privilege: PrivilegeAdmin,
+	}))
+	assert.NoError(t, handler.Process(&UserRemoved{Email: "jim@example.org", CompanyID: "abc-123"}))
+	assert.NoError(t, handler.Process(&UserAdded{Email: "jim@example.org", CompanyID: "abc-123"}))
+
+	// Membership is back, without the privileges the removal took away.
+	assert.Equal(t, []string{"abc-123"}, handler.CompaniesByUser("jim@example.org", func(CompanyPrivileges) bool {
+		return true
+	}))
+	assert.False(t, handler.IsAllowed("jim@example.org", "abc-123", func(privileges CompanyPrivileges) bool {
+		return privileges.Admin
+	}))
+}
+
 func TestPrivilegeHandler_GetCompanies_Email_Not_Found(t *testing.T) {
 	handler := New(WithBaseURL("base"))