feat: file_save_disk, file_delete, file_serve, upload_parse, upload_handler, thumbnail_generate (issue 0014 fase 3)

functions/infra/thumbnail_generate_test.go

@@ -0,0 +1,109 @@
+package infra
+
+import (
+	"image"
+	"image/color"
+	"image/png"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// genPNG crea un PNG cuadrado de size pixeles en path.
+func genPNG(t *testing.T, path string, size int) {
+	t.Helper()
+	img := image.NewRGBA(image.Rect(0, 0, size, size))
+	for y := 0; y < size; y++ {
+		for x := 0; x < size; x++ {
+			img.Set(x, y, color.RGBA{R: uint8(x % 255), G: uint8(y % 255), B: 100, A: 255})
+		}
+	}
+	f, err := os.Create(path)
+	if err != nil {
+		t.Fatalf("create: %v", err)
+	}
+	defer f.Close()
+	if err := png.Encode(f, img); err != nil {
+		t.Fatalf("encode: %v", err)
+	}
+}
+
+func TestThumbnailGenerate(t *testing.T) {
+	t.Run("genera thumbnail PNG mas pequeno que el original", func(t *testing.T) {
+		dir := t.TempDir()
+		src := filepath.Join(dir, "src.png")
+		dst := filepath.Join(dir, "thumb.png")
+		genPNG(t, src, 400)
+
+		if err := ThumbnailGenerate(src, dst, 100, 100); err != nil {
+			t.Fatalf("ThumbnailGenerate: %v", err)
+		}
+
+		f, err := os.Open(dst)
+		if err != nil {
+			t.Fatalf("open dst: %v", err)
+		}
+		defer f.Close()
+		img, _, err := image.Decode(f)
+		if err != nil {
+			t.Fatalf("decode dst: %v", err)
+		}
+		b := img.Bounds()
+		if b.Dx() > 100 || b.Dy() > 100 {
+			t.Errorf("thumbnail %dx%d, want <= 100x100", b.Dx(), b.Dy())
+		}
+	})
+
+	t.Run("preserva aspect ratio", func(t *testing.T) {
+		dir := t.TempDir()
+		src := filepath.Join(dir, "src.png")
+		dst := filepath.Join(dir, "thumb.png")
+
+		// Imagen 400x200 (aspect 2:1)
+		img := image.NewRGBA(image.Rect(0, 0, 400, 200))
+		f, _ := os.Create(src)
+		png.Encode(f, img)
+		f.Close()
+
+		if err := ThumbnailGenerate(src, dst, 100, 100); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		f2, _ := os.Open(dst)
+		defer f2.Close()
+		thumb, _, _ := image.Decode(f2)
+		b := thumb.Bounds()
+		// Aspect 2:1 mantenido: 100x50
+		if b.Dx() != 100 || b.Dy() != 50 {
+			t.Errorf("thumbnail %dx%d, want 100x50 (aspect 2:1)", b.Dx(), b.Dy())
+		}
+	})
+
+	t.Run("rechaza extension de salida no soportada", func(t *testing.T) {
+		dir := t.TempDir()
+		src := filepath.Join(dir, "src.png")
+		dst := filepath.Join(dir, "thumb.webp")
+		genPNG(t, src, 200)
+		err := ThumbnailGenerate(src, dst, 100, 100)
+		if err == nil {
+			t.Error("got nil err, want extension no soportada")
+		}
+	})
+
+	t.Run("no agranda imagenes ya pequenas", func(t *testing.T) {
+		dir := t.TempDir()
+		src := filepath.Join(dir, "src.png")
+		dst := filepath.Join(dir, "thumb.png")
+		genPNG(t, src, 50)
+
+		if err := ThumbnailGenerate(src, dst, 200, 200); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		f, _ := os.Open(dst)
+		defer f.Close()
+		thumb, _, _ := image.Decode(f)
+		b := thumb.Bounds()
+		if b.Dx() != 50 || b.Dy() != 50 {
+			t.Errorf("thumbnail %dx%d, want 50x50 (sin agrandar)", b.Dx(), b.Dy())
+		}
+	})
+}