extraction_line_callback_external_test.go RawHistoryFolder

1package vt_test
2
3import (
4	"testing"
5
6	vt "github.com/bnema/vev-vt"
7	"github.com/bnema/vev-vt/core"
8)
9
10func TestExternalLineEvictionCallbackReceivesStableCopy(t *testing.T) {
11	screen := vt.NewScreen(4, 3)
12	inWrite := false
13	var evicted [][]core.Cell
14	screen.OnLineEvicted = func(row []core.Cell) {
15		if !inWrite {
16			t.Error("line eviction callback ran after Write returned")
17		}
18		evicted = append(evicted, row)
19	}
20
21	inWrite = true
22	screen.Write([]byte("AAAA\r\nBBBB\r\nCCCC\r\n"))
23	inWrite = false
24
25	if len(evicted) != 1 || len(evicted[0]) != 4 || evicted[0][0].Rune != 'A' {
26		t.Fatalf("evicted rows = %#v, want one stable AAAA row", evicted)
27	}
28	evicted[0][0] = core.Cell{Rune: 'X'}
29	if got := screen.Frame.At(0, 0).Rune; got != 'B' {
30		t.Fatalf("mutating callback row changed live frame to %q", got)
31	}
32	if got := evicted[0][0].Rune; got != 'X' {
33		t.Fatalf("callback row was not retained as a stable copy: %q", got)
34	}
35}