package runner

import (
	"path/filepath"
	"testing"
	"time"
)

// The stdout cap must END an endless writer, not merely stop reading it. The mechanism is exec's
// own: when limitedBuffer refuses a Write, the copy goroutine closes the pipe's read end («in case
// io.Copy stopped due to write error», os/exec writerDescriptor) and the child dies on EPIPE at
// its next print — no explicit Kill here, unlike drain(), whose StdoutPipe reader gets no such
// help. A workflow review claimed the child blocks on a full pipe until the caller's deadline;
// this pin is the refutation, and it is what fails if the cap ever stops refusing the Write.
func TestAnEndlessBankApplyIsRefusedRatherThanRead(t *testing.T) {
	bin := fakeEngine(t, `exec yes '{"report_version":"tm-bank-decisions-report-v2"}'`)
	start := time.Now()
	_, err := New(nil).BankApply(t.Context(), bin, t.TempDir(), filepath.Join(t.TempDir(), "d.json"), false)
	if err == nil {
		t.Fatal("an endless report was read to the end")
	}
	if took := time.Since(start); took > 30*time.Second {
		t.Fatalf("the overflow did not end the child: the call took %v", took)
	}
}