Function TestPrintWithDimensions_MultipleRendersFit

cmd/display/tty_test.go:644–670

TestPrintWithDimensions_MultipleRendersFit verifies the cross-render aspect of docker/compose#13595: even a single overflowing line desyncs the cursor on the following tick because aec.Up(numLines) counts logical lines while the terminal wraps visual lines. Use many concurrent parent tasks with wide

(t *testing.T)

// loop can't bring every line under terminalWidth without dropping size
// info from progress.
func TestPrintWithDimensions_MultipleRendersFit(t *testing.T) {
	w, buf := newTestWriter()
	// Two parents so the truncation loop must walk multiple lines; 30 children
	// per parent makes each progress bar wide enough that taskID truncation
	// alone can't bring the line under terminalWidth.
	for i := range 2 {
		addParentWithDownloadingChildren(w,
			"Image very-long-name-image-"+string(rune('a'+i))+":v1.2.3",
			30, 100_000_000)
	}

	terminalWidth := 60
	for tick := range 10 {
		for _, t := range w.tasks {
			if t.status == api.Working && t.total > 0 {
				t.current = min(t.current+t.total/10, t.total)
			}
		}
		buf.Reset()
		w.printWithDimensions(terminalWidth, 24)
		for i, line := range extractLines(buf) {
			assert.Assert(t, lenAnsi(line) <= terminalWidth,
				"tick %d line %d has length %d > terminalWidth %d: %q",
				tick, i, lenAnsi(line), terminalWidth, line)
		}
	}
}