go / expert
Snippet
Subprocess Signal Trapping and Isolation Testing via Environment Flag Triggers
Testing OS signal handlers or process termination logic safely requires executing a separate subprocess so os.Exit calls do not crash the primary test runner. This pattern re-executes the current test binary with a guard environment variable to isolate signal delivery.
snippet.go
go
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package mainimport ("os""os/exec""os/signal""syscall""testing""time")func TestSignalHandlingProcess(t *testing.T) {if os.Getenv("BE_SUBPROCESS") == "1" {sigChan := make(chan os.Signal, 1)signal.Notify(sigChan, syscall.SIGTERM)select {case sig := <-sigChan:if sig == syscall.SIGTERM {os.Exit(0)}case <-time.After(2 * time.Second):os.Exit(1)}return}cmd := exec.Command(os.Args[0], "-test.run=TestSignalHandlingProcess")cmd.Env = append(os.Environ(), "BE_SUBPROCESS=1")if err := cmd.Start(); err != nil {t.Fatalf("Failed to launch subprocess: %v", err)}time.Sleep(100 * time.Millisecond)_ = cmd.Process.Signal(syscall.SIGTERM)_ = cmd.Wait()}
Breakdown
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if os.Getenv("BE_SUBPROCESS") == "1" {
Branching entry point that turns the running binary into a dedicated subprocess worker.
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cmd := exec.Command(os.Args[0], "-test.run=TestSignalHandlingProcess")
Re-executes the current compiled test executable targeting the specific test function.