feat: image variants engine

2026-10-08 02:33:32 +02:00
1 parent f0845de643
commit f1d56ef50e
@@ -0,0 +1,129 @@
+package test
+
+import (
+	domain "RenewCMS/internal/domain/image"
+	"bytes"
+	"errors"
+	"image"
+	"image/color"
+	"image/gif"
+	"testing"
+)
+
+func bandedTallImage() *image.NRGBA {
+	canvas := image.NewNRGBA(image.Rect(0, 0, 20, 60))
+	for y := 0; y < 60; y++ {
+		fill := variantGreen
+		if y < 15 {
+			fill = variantRed
+		}
+		if y >= 45 {
+			fill = variantBlue
+		}
+		for x := 0; x < 20; x++ {
+			canvas.SetNRGBA(x, y, fill)
+		}
+	}
+	return canvas
+}
+
+func globalPaletteGIF(t *testing.T, frames int) []byte {
+	t.Helper()
+	palette := color.Palette{color.White, color.Black, color.RGBA{R: 255, A: 255}, color.RGBA{B: 255, A: 255}}
+	animation := &gif.GIF{Config: image.Config{ColorModel: palette, Width: 8, Height: 8}}
+	for frame := 0; frame < frames; frame++ {
+		paletted := image.NewPaletted(image.Rect(0, 0, 8, 8), palette)
+		paletted.SetColorIndex(frame, frame, 1)
+		animation.Image = append(animation.Image, paletted)
+		animation.Delay = append(animation.Delay, 10)
+	}
+	var buffer bytes.Buffer
+	if err := gif.EncodeAll(&buffer, animation); err != nil {
+		t.Fatalf("gif encode failed: %v", err)
+	}
+	return buffer.Bytes()
+}
+
+func TestVariantGeometryPixelGaps(t *testing.T) {
+	t.Run("Cover on a tall source keeps the middle band", func(t *testing.T) {
+		rendered := renderVariant(t, encodePNG(t, bandedTallImage()), variantSettings(20, 20, domain.FitCover, domain.FormatPNG))
+
+		decoded, _ := decodeImage(t, rendered.Content)
+		if decoded.Bounds().Dx() != 20 || decoded.Bounds().Dy() != 20 {
+			t.Fatalf("output = %v", decoded.Bounds())
+		}
+		for _, y := range []int{0, 10, 19} {
+			if got := pixelAt(decoded, 10, y); got != variantGreen {
+				t.Errorf("pixel 10,%d = %v, want green", y, got)
+			}
+		}
+	})
+
+	t.Run("Inside on a tall source scales the whole picture", func(t *testing.T) {
+		rendered := renderVariant(t, encodePNG(t, bandedTallImage()), variantSettings(10, 30, domain.FitInside, domain.FormatPNG))
+
+		decoded, _ := decodeImage(t, rendered.Content)
+		if decoded.Bounds().Dx() != 10 || decoded.Bounds().Dy() != 30 {
+			t.Fatalf("output = %v", decoded.Bounds())
+		}
+		want := map[int]color.NRGBA{1: variantRed, 15: variantGreen, 28: variantBlue}
+		for y, expected := range want {
+			assertNearColor(t, pixelAt(decoded, 5, y), expected)
+		}
+	})
+
+	t.Run("Contain pads horizontally around a narrow source", func(t *testing.T) {
+		rendered := renderVariant(t, encodePNG(t, variantSolidImage(20, 40, variantRed)), variantSettings(40, 40, domain.FitContain, domain.FormatPNG))
+
+		decoded, _ := decodeImage(t, rendered.Content)
+		for y := 0; y < 40; y += 13 {
+			for _, x := range []int{0, 9, 30, 39} {
+				if got := pixelAt(decoded, x, y); got.A != 0 {
+					t.Fatalf("pixel %d,%d = %v, want transparent", x, y, got)
+				}
+			}
+			for _, x := range []int{10, 19, 29} {
+				if got := pixelAt(decoded, x, y); got != variantRed {
+					t.Fatalf("pixel %d,%d = %v, want red", x, y, got)
+				}
+			}
+		}
+	})
+
+	t.Run("Contain keeps a box that is larger in one direction only", func(t *testing.T) {
+		for _, row := range []struct{ width, height, wantWidth, wantHeight int }{
+			{200, 100, 200, 100},
+			{100, 200, 100, 200},
+		} {
+			rendered := renderVariant(t, solidPNG(t, 100, 100), variantSettings(row.width, row.height, domain.FitContain, domain.FormatPNG))
+
+			width, height := decodedSize(t, rendered.Content)
+			if width != row.wantWidth || height != row.wantHeight {
+				t.Errorf("output = %dx%d, want %dx%d", width, height, row.wantWidth, row.wantHeight)
+			}
+		}
+	})
+}
+
+func TestAnimatedGIFDetectionWithGlobalPalette(t *testing.T) {
+	animated, err := domain.IsAnimatedGIF(bytes.NewReader(globalPaletteGIF(t, 2)))
+	if err != nil || !animated {
+		t.Errorf("two frames: animated = %v, err = %v", animated, err)
+	}
+
+	animated, err = domain.IsAnimatedGIF(bytes.NewReader(globalPaletteGIF(t, 1)))
+	if err != nil || animated {
+		t.Errorf("one frame: animated = %v, err = %v", animated, err)
+	}
+}
+
+func TestVariantRequestErrorMessages(t *testing.T) {
+	unknown := domain.NewUnknownVariantError("thumb")
+	if unknown.Error() != "unknown variant: thumb" || !errors.Is(unknown, domain.ErrUnknownVariant) {
+		t.Errorf("unknown = %q", unknown.Error())
+	}
+	unsupported := domain.NewUnsupportedParameterError("w")
+	if unsupported.Error() != "unsupported parameter: w" || !errors.Is(unsupported, domain.ErrUnsupportedParameter) {
+		t.Errorf("unsupported = %q", unsupported.Error())
+	}
+}