fix: checker map mutation

ocis-pkg/handlers/checker.go

@@ -50,14 +50,16 @@ func (c CheckHandlerConfiguration) WithCheck(name string, check checker) CheckHa
 		c.logger.Panic().Str("check", name).Msg("check already exists")
 	}
 
+	c.checks = maps.Clone(c.checks) // prevent propagated check duplication, maps are references;
 	c.checks[name] = check
+
 	return c
 }
 
 // WithChecks adds multiple checks to the CheckHandlerConfiguration.
 func (c CheckHandlerConfiguration) WithChecks(checks checkers) CheckHandlerConfiguration {
 	for name, check := range checks {
-		c.WithCheck(name, check)
+		c.checks = c.WithCheck(name, check).checks
 	}
 
 	return c

ocis-pkg/handlers/checker_test.go

@@ -21,13 +21,15 @@ func TestCheckHandlerConfiguration(t *testing.T) {
 	handlerConfiguration := handlers.NewCheckHandlerConfiguration().WithCheck("check-1", nopCheck)
 
 	t.Run("add check", func(t *testing.T) {
-		handlerConfiguration.WithCheck("check-2", nopCheck)
+		inheritedHandlerConfiguration := handlerConfiguration.WithCheck("check-2", nopCheck)
-		require.Equal(t, 2, len(handlers.NewCheckHandler(handlerConfiguration).Checks()))
+		require.Equal(t, 1, len(handlers.NewCheckHandler(handlerConfiguration).Checks()))
+		require.Equal(t, 2, len(handlers.NewCheckHandler(inheritedHandlerConfiguration).Checks()))
 	})
 
 	t.Run("add checks", func(t *testing.T) {
-		handlerConfiguration.WithChecks(map[string]func(ctx context.Context) error{"check-3": nopCheck, "check-4": nopCheck})
+		inheritedHandlerConfiguration := handlerConfiguration.WithChecks(map[string]func(ctx context.Context) error{"check-2": nopCheck, "check-3": nopCheck})
-		require.Equal(t, 4, len(handlers.NewCheckHandler(handlerConfiguration).Checks()))
+		require.Equal(t, 1, len(handlers.NewCheckHandler(handlerConfiguration).Checks()))
+		require.Equal(t, 3, len(handlers.NewCheckHandler(inheritedHandlerConfiguration).Checks()))
 	})
 
 	t.Run("checks are unique", func(t *testing.T) {