Show poster thumbnails in the detail panes

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/ui/cover_test.go

@@ -0,0 +1,149 @@
+package ui
+
+import (
+	"bytes"
+	"context"
+	"image"
+	"image/color"
+	"image/jpeg"
+	"image/png"
+	"testing"
+	"time"
+
+	"github.com/gdamore/tcell/v2"
+)
+
+// stripes returns a w×h image whose top half is red and bottom half blue.
+func stripes(w, h int) *image.RGBA {
+	img := image.NewRGBA(image.Rect(0, 0, w, h))
+	for y := 0; y < h; y++ {
+		for x := 0; x < w; x++ {
+			c := color.RGBA{255, 0, 0, 255}
+			if y >= h/2 {
+				c = color.RGBA{0, 0, 255, 255}
+			}
+			img.SetRGBA(x, y, c)
+		}
+	}
+	return img
+}
+
+func TestBoxScaleAverages(t *testing.T) {
+	src := image.NewRGBA(image.Rect(0, 0, 2, 2))
+	src.SetRGBA(0, 0, color.RGBA{200, 0, 0, 255})
+	src.SetRGBA(1, 0, color.RGBA{0, 0, 0, 255})
+	src.SetRGBA(0, 1, color.RGBA{0, 0, 0, 255})
+	src.SetRGBA(1, 1, color.RGBA{0, 0, 0, 255})
+	got := boxScale(src, 1, 1).RGBAAt(0, 0)
+	if got.R < 49 || got.R > 51 || got.G != 0 || got.A != 255 {
+		t.Errorf("average = %+v, want R≈50", got)
+	}
+	// Upscaling must not leave holes.
+	up := boxScale(stripes(1, 2), 3, 4)
+	if up.RGBAAt(2, 0).R != 255 || up.RGBAAt(2, 3).B != 255 {
+		t.Errorf("upscaled corners: %+v %+v", up.RGBAAt(2, 0), up.RGBAAt(2, 3))
+	}
+}
+
+func TestDecodeCover(t *testing.T) {
+	var buf bytes.Buffer
+	if err := jpeg.Encode(&buf, stripes(300, 450), nil); err != nil {
+		t.Fatal(err)
+	}
+	img, err := decodeCover(buf.Bytes())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if b := img.Bounds(); b.Dy() != storedCoverHeight || b.Dx() != 106 {
+		t.Errorf("stored size %v, want 106x%d", b, storedCoverHeight)
+	}
+
+	buf.Reset()
+	if err := png.Encode(&buf, stripes(20, 30)); err != nil {
+		t.Fatal(err)
+	}
+	if img, err := decodeCover(buf.Bytes()); err != nil || img.Bounds().Dy() != 30 {
+		t.Errorf("small png kept as is: %v %v", img, err)
+	}
+
+	if _, err := decodeCover([]byte("<html>not an image</html>")); err == nil {
+		t.Error("garbage must be rejected")
+	}
+	// A header that promises a huge image is refused before decoding it.
+	var huge bytes.Buffer
+	huge.Write([]byte("\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR\x00\x00\x27\x10\x00\x00\x27\x10\x08\x02\x00\x00\x00"))
+	if _, err := decodeCover(huge.Bytes()); err == nil {
+		t.Error("oversized image must be rejected")
+	}
+}
+
+func TestCoverViewDrawsHalfBlocks(t *testing.T) {
+	screen := tcell.NewSimulationScreen("")
+	if err := screen.Init(); err != nil {
+		t.Fatal(err)
+	}
+	defer screen.Fini()
+	screen.SetSize(20, 10)
+
+	c := newCoverView()
+	c.setImage(stripes(40, 60)) // 2:3 poster
+	c.SetRect(0, 0, 20, 10)     // 20 columns × 20 pixel rows: a 13×20 pixel poster
+	c.Draw(screen)
+
+	// Row 0 holds pixel rows 0 (top) and 1: both red. The middle cell row
+	// (index 4/5) crosses into blue; the last row is blue on both halves.
+	rgba := func(c tcell.Color) color.RGBA {
+		r, g, b := c.RGB()
+		return color.RGBA{uint8(r), uint8(g), uint8(b), 255}
+	}
+	check := func(row int, wantFg, wantBg color.RGBA) {
+		t.Helper()
+		ch, _, style, _ := screen.GetContent(0, row)
+		fg, bg, _ := style.Decompose()
+		if ch != '▀' || rgba(fg) != wantFg || rgba(bg) != wantBg {
+			t.Errorf("row %d: %q fg=%v bg=%v", row, ch, rgba(fg), rgba(bg))
+		}
+	}
+	red, blue := color.RGBA{255, 0, 0, 255}, color.RGBA{0, 0, 255, 255}
+	check(0, red, red)
+	check(9, blue, blue)
+	// Beyond the poster's width nothing is drawn.
+	if ch, _, _, _ := screen.GetContent(19, 0); ch == '▀' {
+		t.Error("poster stretched beyond its aspect ratio")
+	}
+}
+
+func TestLoadCoverCachesAndDedupes(t *testing.T) {
+	a := newTestApp(t)
+	fetches := 0
+	var buf bytes.Buffer
+	png.Encode(&buf, stripes(10, 20))
+	ref := coverRef{key: "k", fetch: func(context.Context) ([]byte, error) {
+		fetches++
+		return buf.Bytes(), nil
+	}}
+
+	// Run posted callbacks inline instead of through the (not running) event loop.
+	delivered := make(chan error, 2)
+	a.loadCover(ref, func(_ *image.RGBA, err error) { delivered <- err })
+	a.loadCover(ref, func(_ *image.RGBA, err error) { delivered <- err }) // joins the request in flight
+	if len(a.coverCache.waiting["k"]) != 2 {
+		t.Fatalf("waiters = %d, want 2", len(a.coverCache.waiting["k"]))
+	}
+	if fetches > 1 {
+		t.Errorf("fetched %d times", fetches)
+	}
+}
+
+func TestLoadCoverRemembersFailures(t *testing.T) {
+	a := newTestApp(t)
+	a.coverCache.failed["bad"] = time.Now()
+	var gotErr error
+	a.loadCover(coverRef{key: "bad", fetch: func(context.Context) ([]byte, error) {
+		t.Error("a recent failure must not be retried")
+		return nil, nil
+	}}, func(_ *image.RGBA, err error) { gotErr = err })
+	if gotErr == nil {
+		t.Error("expected an error for a recently failed cover")
+	}
+}