Function TestMonitorProcess_StderrCaptured

go/client_test.go:2514–2545

TestMonitorProcess_StderrCaptured validates that when the CLI process writes an error to stderr and exits, the stderr content IS included in the process error (now that startCLIServer sets Stderr).

(t *testing.T)

// writes an error to stderr and exits, the stderr content IS included
// in the process error (now that startCLIServer sets Stderr).
func TestMonitorProcess_StderrCaptured(t *testing.T) {
	client := &Client{
		sessions: make(map[string]*Session),
	}

	stderrMsg := "error: authentication failed: invalid token"
	client.process = exec.Command(os.Args[0], "-test.run=TestHelperProcess", "--", stderrMsg)
	client.process.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")

	// Replicate what startCLIServer now does: capture stderr.
	client.process.Stderr = truncbuffer.NewTruncBuffer(stderrBufferSize)

	if err := client.process.Start(); err != nil {
		t.Fatalf("failed to start test process: %v", err)
	}

	client.monitorProcess()

	// Wait for the process to exit.
	<-client.processDone

	processError := *client.processErrorPtr
	if processError == nil {
		t.Fatal("expected a process error after non-zero exit, got nil")
	}

	if !strings.Contains(processError.Error(), stderrMsg) {
		t.Errorf("stderr output not included in process error.\n"+
			"  got:  %q\n"+
			"  want: error containing %q", processError.Error(), stderrMsg)
	}
}

// TestMonitorProcess_StderrCapturedOnZeroExit validates that even when the
// CLI process exits with code 0, stderr content is included in the error.