1 files changed, 46 insertions, 7 deletions

diff --git a/internal/notify/image_test.go b/internal/notify/image_test.go
index 2db4c75..7121f32 100644
--- a/internal/notify/image_test.go
+++ b/internal/notify/image_test.go
@@ -13,6 +13,8 @@ package notify
 
 import (
 	"bytes"
+	"image"
+	"image/color"
 	"image/png"
 	"testing"
 
@@ -70,10 +72,23 @@ func TestImagePathFromHints(t *testing.T) {
 	}
 }
 
+// checkPixel asserts the RGBA of img at (x,y) matches want.
+func checkPixel(t *testing.T, img image.Image, x, y int, want color.RGBA) {
+	t.Helper()
+	r, g, b, a := img.At(x, y).RGBA()
+	if r>>8 != uint32(want.R) || g>>8 != uint32(want.G) || b>>8 != uint32(want.B) || a>>8 != uint32(want.A) {
+		t.Fatalf("pixel (%d,%d) = %d %d %d %d, want %v", x, y, r>>8, g>>8, b>>8, a>>8, want)
+	}
+}
+
 func TestRawImagePNG(t *testing.T) {
-	// 2x1 RGBA on a rowstride wider than the data, to prove stride is honoured.
-	r := &RawImage{Width: 2, Height: 1, RowStride: 12, HasAlpha: true, BitsPerSample: 8, Channels: 4,
-		Data: []byte{255, 0, 0, 255, 0, 255, 0, 255, 9, 9, 9, 9}}
+	// 2x2 RGBA with a rowstride wider than Width*Channels. The second row is
+	// the point: if stride were ignored, row 1 would read the row-0 padding.
+	r := &RawImage{Width: 2, Height: 2, RowStride: 12, HasAlpha: true, BitsPerSample: 8, Channels: 4,
+		Data: []byte{
+			255, 0, 0, 255, 0, 255, 0, 255, 9, 9, 9, 9, // row 0: red, green, pad
+			0, 0, 255, 255, 255, 255, 255, 255, 9, 9, 9, 9, // row 1: blue, white, pad
+		}}
 	data, err := r.PNG()
 	if err != nil {
 		t.Fatalf("PNG: %v", err)
@@ -82,13 +97,32 @@ func TestRawImagePNG(t *testing.T) {
 	if err != nil {
 		t.Fatalf("decode: %v", err)
 	}
-	if img.Bounds().Dx() != 2 || img.Bounds().Dy() != 1 {
+	if img.Bounds().Dx() != 2 || img.Bounds().Dy() != 2 {
 		t.Fatalf("bounds = %v", img.Bounds())
 	}
-	r0, g0, b0, a0 := img.At(0, 0).RGBA()
-	if r0>>8 != 255 || g0>>8 != 0 || b0>>8 != 0 || a0>>8 != 255 {
-		t.Fatalf("pixel 0 = %d %d %d %d", r0>>8, g0>>8, b0>>8, a0>>8)
+	checkPixel(t, img, 0, 0, color.RGBA{255, 0, 0, 255})
+	checkPixel(t, img, 1, 0, color.RGBA{0, 255, 0, 255})
+	checkPixel(t, img, 0, 1, color.RGBA{0, 0, 255, 255})
+	checkPixel(t, img, 1, 1, color.RGBA{255, 255, 255, 255})
+}
+
+func TestRawImagePNGThreeChannel(t *testing.T) {
+	// 2x1 RGB, no alpha byte: PNG() must force opaque.
+	r := &RawImage{Width: 2, Height: 1, RowStride: 6, HasAlpha: false, BitsPerSample: 8, Channels: 3,
+		Data: []byte{255, 0, 0, 0, 255, 0}}
+	data, err := r.PNG()
+	if err != nil {
+		t.Fatalf("PNG: %v", err)
 	}
+	img, err := png.Decode(bytes.NewReader(data))
+	if err != nil {
+		t.Fatalf("decode: %v", err)
+	}
+	if img.Bounds().Dx() != 2 || img.Bounds().Dy() != 1 {
+		t.Fatalf("bounds = %v", img.Bounds())
+	}
+	checkPixel(t, img, 0, 0, color.RGBA{255, 0, 0, 255})
+	checkPixel(t, img, 1, 0, color.RGBA{0, 255, 0, 255})
 }
 
 func TestRawImagePNGRejectsBadData(t *testing.T) {
@@ -98,4 +132,9 @@ func TestRawImagePNGRejectsBadData(t *testing.T) {
 	if _, err := (&RawImage{Width: 1, Height: 1, Channels: 2, BitsPerSample: 8}).PNG(); err == nil {
 		t.Fatal("channels 2 must error")
 	}
+	// 2x2 RGBA needs 16 bytes; the slice holds one row.
+	if _, err := (&RawImage{Width: 2, Height: 2, RowStride: 8, BitsPerSample: 8, Channels: 4,
+		Data: []byte{0, 0, 0, 255, 255, 255, 255, 255}}).PNG(); err == nil {
+		t.Fatal("short data must error")
+	}
 }