internal/handlers/avif_too_large_internal_test.go

@@ -0,0 +1,49 @@
+package handlers
+
+import (
+	"fmt"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"sneak.berlin/go/pixa/internal/imageprocessor"
+	"sneak.berlin/go/pixa/internal/imgcache"
+)
+
+// TestAVIFOutputTooLargeAnswers400 checks that respondImageError and
+// handleImageError, which answer the errors of the two image routes, answer
+// 400 naming the AVIF pixel limit when the image processor refuses an AVIF
+// output above it, wrapped as the service wraps it. The request's source only
+// goes into a log line, so it is left empty.
+func TestAVIFOutputTooLargeAnswers400(t *testing.T) {
+	t.Parallel()
+
+	h := &Handlers{log: slog.New(slog.DiscardHandler)}
+	err := fmt.Errorf("image processing failed: %w: 4097x4096",
+		imageprocessor.ErrAVIFOutputTooLarge)
+	wantBody := fmt.Sprintf("above %d pixels", imageprocessor.MaxAVIFOutputPixels)
+
+	plain := httptest.NewRecorder()
+	h.respondImageError(plain, &imgcache.ImageRequest{}, err)
+
+	encrypted := httptest.NewRecorder()
+	h.handleImageError(encrypted, err)
+
+	for name, rec := range map[string]*httptest.ResponseRecorder{
+		"respondImageError": plain, "handleImageError": encrypted,
+	} {
+		t.Logf("%s: status = %d, body = %q", name, rec.Code, rec.Body.String())
+
+		if rec.Code != http.StatusBadRequest {
+			t.Errorf("%s: status = %d, want %d",
+				name, rec.Code, http.StatusBadRequest)
+		}
+
+		if !strings.Contains(rec.Body.String(), wantBody) {
+			t.Errorf("%s: body = %q, want it to say %q",
+				name, rec.Body.String(), wantBody)
+		}
+	}
+}

internal/imageprocessor/avif_too_large_internal_test.go

@@ -0,0 +1,84 @@
+package imageprocessor
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"os"
+	"testing"
+)
+
+// TestImageProcessor_RefusesAVIFAboveMaxPixels verifies that an AVIF output
+// of more than MaxAVIFOutputPixels is refused with ErrAVIFOutputTooLarge
+// before anything is decoded, whatever size and fit give it, the source's own
+// size included, and that an AVIF output of at most that many pixels, or one
+// in another format, is not. One input is a 64x32 PNG cut off in its pixel
+// data. The other is testdata/red.avif, a 4x4 AVIF, with the size in its
+// header changed to 4097x4096. libvips reads each input's size from its
+// header but fails when it decodes its pixel data, so a request that gets
+// that failure was not refused, and a refusal came before any decoding.
+func TestImageProcessor_RefusesAVIFAboveMaxPixels(t *testing.T) {
+	t.Parallel()
+
+	whole := createTestPNG(t, 64, 32)
+	cutOff := whole[:len(whole)/2]
+
+	largeAVIF, err := os.ReadFile("testdata/red.avif")
+	if err != nil {
+		t.Fatalf("failed to read test AVIF: %v", err)
+	}
+
+	// The ispe box gives the width and then the height, 4 bytes each, after
+	// the box's type and its 4 bytes of version and flags
+	ispe := bytes.Index(largeAVIF, []byte("ispe"))
+	binary.BigEndian.PutUint32(largeAVIF[ispe+8:], 4097)
+	binary.BigEndian.PutUint32(largeAVIF[ispe+12:], 4096)
+
+	tests := []struct {
+		name          string
+		input         []byte
+		format        Format
+		width, height int
+		fit           FitMode
+		refused       bool
+	}{
+		{"AVIF at the limit", cutOff, FormatAVIF, 4096, 4096, FitCover, false},
+		{"AVIF above the limit", cutOff, FormatAVIF, 4096, 4097, FitCover, true},
+		{"WebP above the AVIF limit", cutOff, FormatWebP, 4096, 4097, FitCover, false},
+		// FitInside does not enlarge, so the output stays 64x32
+		{"AVIF inside a larger size", cutOff, FormatAVIF, 8192, 8192, FitInside, false},
+		// FitOutside scales 64x32 by 128 to cover 8192x1: 8192x4096
+		{"AVIF outside a smaller size", cutOff, FormatAVIF, 8192, 1, FitOutside, true},
+		// With no size, the output keeps the source's 4097x4096
+		{"AVIF of the source's size", largeAVIF, FormatAVIF, 0, 0, FitCover, true},
+		{"orig of an AVIF source", largeAVIF, FormatOriginal, 0, 0, FitCover, true},
+		{"JPEG of the source's size", largeAVIF, FormatJPEG, 0, 0, FitCover, false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			_, err := New(Params{}).Process(t.Context(), bytes.NewReader(tt.input),
+				&Request{
+					Size:    Size{Width: tt.width, Height: tt.height},
+					Format:  tt.format,
+					FitMode: tt.fit,
+				})
+			t.Logf("Process() error = %v", err)
+
+			if tt.refused {
+				if !errors.Is(err, ErrAVIFOutputTooLarge) {
+					t.Errorf("Process() error = %v, want %v", err, ErrAVIFOutputTooLarge)
+				}
+
+				return
+			}
+
+			if err == nil || errors.Is(err, ErrAVIFOutputTooLarge) {
+				t.Errorf("Process() error = %v, want the failure to decode "+
+					"the input", err)
+			}
+		})
+	}
+}

internal/imageprocessor/encoder_settings_internal_test.go

@@ -77,10 +77,10 @@ func TestImageProcessor_PNGIsCompressed(t *testing.T) {
 	}
 }
 
-// TestImageProcessor_WebPAtDefaultEffort verifies that WebP is saved at
-// libvips' default effort, 4: the output is the size of the same image saved
-// at that effort.
-func TestImageProcessor_WebPAtDefaultEffort(t *testing.T) {
+// TestImageProcessor_WebPAtEffort2 verifies that WebP is saved at effort 2,
+// not libvips' default of 4: the output is the size of the same image saved
+// at effort 2.
+func TestImageProcessor_WebPAtEffort2(t *testing.T) {
 	t.Parallel()
 
 	input := createTestJPEG(t, 200, 150)
@@ -90,14 +90,14 @@ func TestImageProcessor_WebPAtDefaultEffort(t *testing.T) {
 	want, _, err := decode(t, input).ExportWebp(&vips.WebpExportParams{
 		StripMetadata:   true,
 		Quality:         85,
-		ReductionEffort: 4,
+		ReductionEffort: 2,
 	})
 	if err != nil {
 		t.Fatalf("ExportWebp() error = %v", err)
 	}
 
 	if size != int64(len(want)) {
-		t.Errorf("WebP output is %d bytes, want %d, the size at effort 4",
+		t.Errorf("WebP output is %d bytes, want %d, the size at effort 2",
 			size, len(want))
 	}
 }
@@ -143,3 +143,29 @@ func TestImageProcessor_AVIFAtEffort1(t *testing.T) {
 			"and 8 bits", size, len(want))
 	}
 }
+
+// TestImageProcessor_JPEGXLAtEffort4 verifies that JPEG XL is saved at
+// effort 4, not libvips' default of 7: the output is the size of the same
+// image saved at effort 4, with the distance exportJXL gives quality 85.
+func TestImageProcessor_JPEGXLAtEffort4(t *testing.T) {
+	t.Parallel()
+
+	input := createTestJPEG(t, 200, 150)
+
+	size := processedSize(t, input, &Request{Format: FormatJXL, Quality: 85})
+
+	params := vips.NewJxlExportParams()
+	params.Quality = 85
+	params.Distance = jxlDistance(85)
+	params.Effort = 4
+
+	want, _, err := decode(t, input).ExportJxl(params)
+	if err != nil {
+		t.Fatalf("ExportJxl() error = %v", err)
+	}
+
+	if size != int64(len(want)) {
+		t.Errorf("JPEG XL output is %d bytes, want %d, the size at effort 4",
+			size, len(want))
+	}
+}