printer-driver/emulator/internal/escpos/printer_test.go

package escpos

import (
	"bytes"
	"image/png"
	"os"
	"path/filepath"
	"sync"
	"testing"
)

type recorder struct {
	mu  sync.Mutex
	buf []byte
}

func (r *recorder) reply(b []byte) {
	r.mu.Lock()
	r.buf = append(r.buf, b...)
	r.mu.Unlock()
}

func (r *recorder) take() []byte {
	r.mu.Lock()
	defer r.mu.Unlock()
	b := r.buf
	r.buf = nil
	return b
}

func newTestPrinter(t *testing.T, key string) *Printer {
	t.Helper()
	prof, ok := FindProfile(key)
	if !ok {
		t.Fatalf("perfil %q no existe", key)
	}
	p, err := NewPrinter(prof)
	if err != nil {
		t.Fatal(err)
	}
	return p
}

func blackPixels(p *Printer) int {
	n := 0
	for _, t := range p.Tickets() {
		for _, v := range t.Image.Pix {
			if v < 0x80 {
				n++
			}
		}
	}
	return n
}

func TestTextAndCut(t *testing.T) {
	p := newTestPrinter(t, "80mm")
	s := p.NewSession("test", nil)
	s.Write([]byte("\x1b@Hola mundo\n\x1dVA\x00"))
	if got := len(p.Tickets()); got != 1 {
		t.Fatalf("tickets = %d, want 1", got)
	}
	if blackPixels(p) == 0 {
		t.Fatal("el ticket está en blanco")
	}
}

func TestCutWithoutFeedLeavesTail(t *testing.T) {
	p := newTestPrinter(t, "80mm")
	s := p.NewSession("test", nil)
	s.Write([]byte("linea\n\x1dV\x00"))
	if got := len(p.Tickets()); got != 0 {
		t.Fatalf("con una sola línea bajo la cuchilla no debe salir ticket, salen %d", got)
	}
	s.Write([]byte("\x1dVA\x00"))
	if got := len(p.Tickets()); got != 1 {
		t.Fatalf("tickets = %d, want 1", got)
	}
}

func TestCommandSplitAcrossWrites(t *testing.T) {
	p := newTestPrinter(t, "80mm")
	s := p.NewSession("test", nil)
	img := []byte{0x1d, 'v', '0', 0, 2, 0, 3, 0, 0xff, 0xff, 0x81, 0x81, 0xff, 0xff}
	for _, c := range img {
		s.Write([]byte{c})
	}
	s.Write([]byte("\x1dVA\x00"))
	if blackPixels(p) != 16+4+16 {
		t.Fatalf("píxeles negros = %d, want 36", blackPixels(p))
	}
}

func TestRealtimeStatusWhileCoverOpen(t *testing.T) {
	p := newTestPrinter(t, "80mm")
	var r recorder
	s := p.NewSession("test", r.reply)

	s.Write([]byte{dle, 0x04, 1})
	if got := r.take(); !bytes.Equal(got, []byte{0x12}) {
		t.Fatalf("DLE EOT 1 online = % X, want 12", got)
	}

	p.UpdateStatus(func(st *Status) { st.CoverOpen = true })
	s.Write([]byte("retenido\n"))
	s.Write([]byte{dle, 0x04, 2})
	if got := r.take(); !bytes.Equal(got, []byte{0x12 | 0x04 | 0x40}) {
		t.Fatalf("DLE EOT 2 con tapa abierta = % X, want 56", got)
	}
	if p.Snapshot(0).PendingBytes == 0 {
		t.Fatal("los datos deberían seguir en el buffer")
	}

	p.UpdateStatus(func(st *Status) { st.CoverOpen = false })
	if p.Snapshot(0).PendingBytes != 0 {
		t.Fatal("al cerrar la tapa se debería imprimir el buffer")
	}
}

func TestGSI(t *testing.T) {
	p := newTestPrinter(t, "80mm")
	var r recorder
	s := p.NewSession("test", r.reply)
	s.Write([]byte{gs, 'I', 67})
	if got, want := r.take(), []byte("_ESCPOS-EMU-80\x00"); !bytes.Equal(got, want) {
		t.Fatalf("GS I 67 = %q, want %q", got, want)
	}

	p58 := newTestPrinter(t, "58mm")
	s58 := p58.NewSession("test", r.reply)
	s58.Write([]byte{gs, 'I', 67})
	if got := r.take(); len(got) != 0 {
		t.Fatalf("el perfil 58mm no debería responder a GS I 67, responde %q", got)
	}
}

func TestQRAndDrawer(t *testing.T) {
	p := newTestPrinter(t, "80mm")
	var r recorder
	s := p.NewSession("test", r.reply)
	data := "https://example.com"
	n := len(data) + 3
	cmd := []byte{gs, '(', 'k', byte(n), byte(n >> 8), 49, 80, 48}
	cmd = append(cmd, data...)
	cmd = append(cmd, gs, '(', 'k', 3, 0, 49, 67, 4)
	cmd = append(cmd, gs, '(', 'k', 3, 0, 49, 81, 48)
	cmd = append(cmd, esc, 'p', 0, 25, 250)
	cmd = append(cmd, dle, 0x04, 1)
	cmd = append(cmd, gs, 'V', 'A', 0)
	s.Write(cmd)
	if blackPixels(p) < 500 {
		t.Fatalf("el QR no parece impreso (%d píxeles negros)", blackPixels(p))
	}
	if got := r.take(); !bytes.Equal(got, []byte{0x16}) {
		t.Fatalf("DLE EOT 1 con cajón abierto = % X, want 16", got)
	}
}

// TestSampleReceipt genera un ticket de ejemplo. Con ESCPOS_PNG=dir se
// guarda como PNG para inspeccionarlo a ojo.
func TestSampleReceipt(t *testing.T) {
	p := newTestPrinter(t, "80mm")
	s := p.NewSession("test", nil)
	var b bytes.Buffer
	b.WriteString("\x1b@\x1bt\x13\x1ba\x01\x1d!\x11TIENDA\n\x1d!\x00")
	b.WriteString("\x1bE\x01Negrita\x1bE\x00 normal \x1b-\x01subrayado\x1b-\x00\n")
	b.WriteString("\x1ba\x00Ca\xa4a  1,50 \xd5\n") // PC858: ñ y €
	b.WriteString("\x1dB\x01 INVERTIDO \x1dB\x00\x1bM\x01 fuente B\x1bM\x00\n")
	b.WriteString("\x1ba\x02Total: 12,00\n\x1ba\x00")
	b.WriteString("Col1\tCol2\tCol3\n")
	b.WriteString("\x1dVB\x10")
	s.Write(b.Bytes())

	tix := p.Tickets()
	if len(tix) != 1 {
		t.Fatalf("tickets = %d, want 1", len(tix))
	}
	if dir := os.Getenv("ESCPOS_PNG"); dir != "" {
		f, err := os.Create(filepath.Join(dir, "sample.png"))
		if err != nil {
			t.Fatal(err)
		}
		defer f.Close()
		if err := png.Encode(f, tix[0].Image); err != nil {
			t.Fatal(err)
		}
	}
}