1 files changed, 73 insertions, 0 deletions
diff --git a/htmlimg_test.go b/htmlimg_test.go
new file mode 100644
index 0000000..a3fa857
--- /dev/null
+++ b/htmlimg_test.go
@@ -0,0 +1,73 @@
+package htmlimg_test
+
+import (
+	"bytes"
+	"encoding/base64"
+	"image"
+	"image/color"
+	"image/png"
+	"math/rand/v2"
+	"regexp"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"git.samanthony.xyz/htmlimg"
+)
+
+var tagExpr = regexp.MustCompile(`^<img src="data:image/png;base64,([A-Za-z0-9+/=]+)">$`)
+
+func TestOutputMatchRegexp(t *testing.T) {
+	t.Parallel()
+	img := newImg(16)
+	tag, err := htmlimg.Encode(img)
+	require.NoError(t, err)
+	require.Regexp(t, tagExpr, tag)
+}
+
+func TestDecodeImg(t *testing.T) {
+	t.Parallel()
+
+	img := newImg(16)
+
+	// Encode <img> tag
+	tag, err := htmlimg.Encode(img)
+	require.NoError(t, err)
+	t.Log(tag)
+
+	// Extract and decode base64 data from tag to get png data
+	groups := tagExpr.FindStringSubmatch(string(tag))
+	require.Len(t, groups, 2)
+	b64 := groups[1]
+	decPng, err := base64.StdEncoding.DecodeString(b64)
+	require.NoError(t, err)
+
+	// Decoded png should match original image's png
+	encPng := new(bytes.Buffer)
+	err = png.Encode(encPng, img)
+	require.NoError(t, err)
+	require.Equal(t, encPng.Bytes(), decPng)
+}
+
+func BenchmarkEncode(b *testing.B) {
+	img := newImg(1024)
+	for b.Loop() {
+		htmlimg.Encode(img)
+	}
+}
+
+func newImg(size int) image.Image {
+	w, h := size, size
+	img := image.NewNRGBA(image.Rect(0, 0, w, h))
+	for y := 0; y < h; y++ {
+		for x := 0; x < w; x++ {
+			img.Set(x, y, color.NRGBA{
+				R: uint8(rand.IntN(256)),
+				G: uint8(rand.IntN(256)),
+				B: uint8(rand.IntN(256)),
+				A: uint8(rand.IntN(256)),
+			})
+		}
+	}
+	return img
+}