better tests

.gitignore

@@ -1,5 +1,5 @@
-bin
-example.*
 test.*
-*.exe
+encoded.*
+decoded.*
+ffwebp.exe
 ffwebp

go.mod

@@ -21,15 +21,19 @@ require (
 	github.com/spakin/netpbm v1.3.2
 	github.com/srwiley/oksvg v0.0.0-20221011165216-be6e8873101c
 	github.com/srwiley/rasterx v0.0.0-20220730225603-2ab79fcdd4ef
+	github.com/stretchr/testify v1.10.0
 	github.com/xyproto/xbm v1.0.0
 	golang.org/x/image v0.30.0
 )
 
 require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/ebitengine/purego v0.8.4 // indirect
 	github.com/gopherjs/gopherjs v1.17.2 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/sergeymakinen/go-bmp v1.0.0 // indirect
 	github.com/tetratelabs/wazero v1.9.0 // indirect
 	golang.org/x/net v0.43.0 // indirect
 	golang.org/x/text v0.28.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -56,5 +56,7 @@ golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
 golang.org/x/sys v0.16.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
 golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

integration/integration_test.go

@@ -0,0 +1,155 @@
+package integration
+
+import (
+	"errors"
+	"fmt"
+	"image/jpeg"
+	"io/fs"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// skip encoding tests for these extensions
+var encodeOnly = map[string]bool{
+	"heic": true,
+	"heif": true,
+	"psd":  true,
+	"svg":  true,
+}
+
+func TestFFWebP(t *testing.T) {
+	// build a fresh executable with "full" tags
+	executable, err := buildExecutable()
+	require.NoError(t, err)
+
+	// resolve all test files
+	files, err := listFiles("images")
+	require.NoError(t, err)
+
+	// test all extensions
+	for _, path := range files {
+		ext := strings.TrimLeft(filepath.Ext(path), ".")
+
+		decoded := "decoded.jpeg"
+		encoded := fmt.Sprintf("encoded.%s", ext)
+
+		// test if we can convert from the codec to jpeg
+		t.Run(fmt.Sprintf("decode %s", ext), func(t *testing.T) {
+			defer os.Remove(decoded)
+
+			err = runCommand(executable, "-i", path, "-o", decoded)
+			require.NoError(t, err)
+
+			err = validateJPEG(decoded, 0)
+			require.NoError(t, err)
+		})
+
+		if encodeOnly[ext] {
+			continue
+		}
+
+		// test if we can convert from jpeg to the codec and then back to jpeg
+		t.Run(fmt.Sprintf("encode %s", ext), func(t *testing.T) {
+			defer os.Remove(encoded)
+			defer os.Remove(decoded)
+
+			err = runCommand(executable, "-i", "example.jpeg", "-o", encoded)
+			require.NoError(t, err)
+
+			err = runCommand(executable, "-i", encoded, "-o", decoded)
+			require.NoError(t, err)
+
+			err = validateJPEG(decoded, 256)
+			require.NoError(t, err)
+		})
+	}
+}
+
+func buildExecutable() (string, error) {
+	if runtime.GOOS == "windows" {
+		err := runCommand("go", "build", "-tags", "full", "-o", "ffwebp.exe", "..\\cmd\\ffwebp")
+		if err != nil {
+			return "", err
+		}
+
+		return "./ffwebp.exe", nil
+	}
+
+	err := runCommand("go", "build", "-tags", "full", "-o", "ffwebp", "../cmd/ffwebp")
+	if err != nil {
+		return "", err
+	}
+
+	err = runCommand("chmod", "+x", "ffwebp")
+	if err != nil {
+		return "", err
+	}
+
+	return "./ffwebp", nil
+}
+
+func listFiles(directory string) ([]string, error) {
+	var files []string
+
+	err := filepath.Walk(directory, func(path string, info fs.FileInfo, err error) error {
+		if err != nil || info.IsDir() {
+			return err
+		}
+
+		files = append(files, path)
+
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return files, nil
+}
+
+func runCommand(command string, args ...string) error {
+	cmd := exec.Command(command, args...)
+
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		if len(out) > 0 {
+			return errors.New(string(out))
+		}
+
+		return err
+	}
+
+	return nil
+}
+
+func validateJPEG(path string, requireSize int) error {
+	file, err := os.OpenFile(path, os.O_RDONLY, 0)
+	if err != nil {
+		return err
+	}
+
+	defer file.Close()
+
+	img, err := jpeg.Decode(file)
+	if err != nil {
+		return err
+	}
+
+	bounds := img.Bounds()
+
+	if bounds.Dx() == 0 || bounds.Dy() == 0 {
+		return fmt.Errorf("invalid dimensions: %dx%d", bounds.Dx(), bounds.Dy())
+	}
+
+	if requireSize != 0 && (bounds.Dx() != requireSize || bounds.Dy() != requireSize) {
+		return fmt.Errorf("mismatched size: %dx%dx", bounds.Dx(), bounds.Dy())
+	}
+
+	return nil
+}

internal/codec/detect.go

@@ -33,7 +33,7 @@ func Sniff(reader io.Reader, input string, ignoreExtension bool) (*Sniffed, io.R
 	if !ignoreExtension {
 		ext := strings.ToLower(strings.TrimPrefix(filepath.Ext(input), "."))
 		if ext != "" {
-			codec, _ := FindCodec(ext)
+			codec, _ := FindCodec(ext, false)
 			if codec != nil {
 				return &Sniffed{
 					Header:     []byte("." + ext),
@@ -95,7 +95,7 @@ func Detect(output, override string) (Codec, string, error) {
 		}
 	}
 
-	codec, err := FindCodec(ext)
+	codec, err := FindCodec(ext, true)
 	if err != nil {
 		return nil, "", err
 	}
@@ -107,7 +107,7 @@ func Detect(output, override string) (Codec, string, error) {
 	return codec, ext, nil
 }
 
-func FindCodec(ext string) (Codec, error) {
+func FindCodec(ext string, requireEncode bool) (Codec, error) {
 	codec, ok := codecs[ext]
 	if ok {
 		return codec, nil
@@ -116,7 +116,7 @@ func FindCodec(ext string) (Codec, error) {
 	for _, codec := range codecs {
 		for _, alias := range codec.Extensions() {
 			if ext == alias {
-				if !codec.CanEncode() {
+				if requireEncode && !codec.CanEncode() {
 					return nil, fmt.Errorf("decode-only output codec: %q", ext)
 				}