Files
玉澜 0fbdfe0130 test(seam): make testseam the only seam-swap form and legislate it
- Add testseam.Protect for save-and-restore seams with no up-front stub
  value (e.g. os.Args mutated by the code under test).
- Migrate all 35 remaining manual prev/assign/t.Cleanup-restore trios to
  testseam.Swap/Protect across app, auth, cli, event, helpers, output,
  pipeline, and shortcut tests; restores can no longer be forgotten.
- check-schema-catalog.sh: fail closed when a manual seam restore
  reappears in any *_test.go (internal/testseam exempt).

Seam injection is now a mechanism, not a convention.
2026-08-03 20:00:47 +08:00

48 lines
1.9 KiB
Go

// Copyright 2026 Alibaba Group
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package testseam turns the package-var injection-seam swap into a mechanism
// instead of a convention. Tests that stub a package-level function var
// (e.g. pipelineBuildEffectiveRegistry) must use Swap so the previous value
// is structurally restored via t.Cleanup; a forgotten restore then cannot
// leak state into sibling tests.
package testseam
import "testing"
// Swap replaces *ptr with next for the duration of the test and restores the
// previous value when the test ends. It is the required form for package-var
// seam swaps:
//
// testseam.Swap(t, &somePackageFn, func(args) (ret, error) { ... })
//
// Prefer it over the manual `prev := fn; t.Cleanup(...); fn = stub` trio:
// Swap cannot forget the restore. Like the manual pattern it replaces, Swap
// mutates process-global state and is therefore NOT safe for t.Parallel tests
// — sequential tests only.
func Swap[T any](t *testing.T, ptr *T, next T) {
t.Helper()
prev := *ptr
*ptr = next
t.Cleanup(func() { *ptr = prev })
}
// Protect snapshots *ptr and restores it at test end without replacing it.
// Use it when the code under test mutates the seam itself (e.g. os.Args) and
// no stub value is available up front. Same sequential-only caveat as Swap.
func Protect[T any](t *testing.T, ptr *T) {
t.Helper()
prev := *ptr
t.Cleanup(func() { *ptr = prev })
}