Adding tests to extract thumbnail with real files

Author: rupor-github

testdata/_Test.azw3

@@ -10,7 +10,7 @@ import (
 )
 
 const (
-	largestKnownSymbol = 834
+	largestKnownSymbol = 851
 )
 
 var (

testdata/_Test.azw8

@@ -75,7 +75,7 @@ type indexTableEntry struct {
 	Offset, Size   uint64
 }
 
-func (e *indexTableEntry) readFrom(r io.Reader, start uint32, limit int, st ion.SymbolTable) error {
+func (e *indexTableEntry) readFrom(r io.Reader, start uint32, limit int) error {
 	*e = indexTableEntry{}
 
 	if err := readDataFrom(r, e); err != nil {
@@ -84,12 +84,6 @@ func (e *indexTableEntry) readFrom(r io.Reader, start uint32, limit int, st ion.
 	if uint64(start)+e.Offset > uint64(limit) {
 		return fmt.Errorf("entity is out of bounds: %d + %d > %d", uint64(start)+e.Offset, e.Size, limit)
 	}
-	if _, ok := st.FindByID(uint64(e.NumID)); !ok {
-		return fmt.Errorf("entity ID not found in the symbol table: %d", e.NumID)
-	}
-	if _, ok := st.FindByID(uint64(e.NumType)); !ok {
-		return fmt.Errorf("entity type not found in the symbol table: %d", e.NumType)
-	}
 	return nil
 }
 

thumbs/kfx/ion.go

@@ -97,7 +97,7 @@ func (r *Reader) extractThumbnail(data []byte) error {
 	var tableEntry indexTableEntry
 	indexTableReader := bytes.NewReader(data[contInfo.IndexTabOffset : contInfo.IndexTabOffset+contInfo.IndexTabLength])
 	for {
-		if err := tableEntry.readFrom(indexTableReader, contHeader.Size, len(data), docSymbols); err != nil {
+		if err := tableEntry.readFrom(indexTableReader, contHeader.Size, len(data)); err != nil {
 			if errors.Is(err, io.EOF) {
 				break
 			}

thumbs/kfx/kfx.go

@@ -0,0 +1,67 @@
+package kfx_test
+
+import (
+	"bytes"
+	"image/jpeg"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"go.uber.org/zap/zaptest"
+
+	"s2k/thumbs/kfx"
+)
+
+const testFile = "../../testdata/_Test.azw8"
+
+func TestNewReader(t *testing.T) {
+	if _, err := os.Stat(testFile); err != nil {
+		t.Skipf("test fixture not available: %v", err)
+	}
+
+	log := zaptest.NewLogger(t)
+
+	const thumbW, thumbH = 330, 470
+
+	r, err := kfx.NewReader(testFile, thumbW, thumbH, log)
+	if err != nil {
+		t.Fatalf("NewReader failed: %v", err)
+	}
+
+	dir := t.TempDir()
+	name, err := r.SaveResult(dir)
+	if err != nil {
+		t.Fatalf("SaveResult failed: %v", err)
+	}
+	if name == "" {
+		t.Fatal("SaveResult returned empty filename — no thumbnail was extracted")
+	}
+
+	t.Logf("saved thumbnail: %s", name)
+
+	// Verify the file is a valid JPEG with expected dimensions.
+	data, err := os.ReadFile(filepath.Join(dir, name))
+	if err != nil {
+		t.Fatalf("unable to read saved thumbnail: %v", err)
+	}
+
+	// SOI marker.
+	if len(data) < 2 || data[0] != 0xFF || data[1] != 0xD8 {
+		t.Fatal("saved file does not start with JPEG SOI marker")
+	}
+
+	// JFIF APP0 segment must be present (Kindle requirement).
+	if len(data) < 4 || data[2] != 0xFF || data[3] != 0xE0 {
+		t.Fatal("saved file does not contain JFIF APP0 segment")
+	}
+
+	img, err := jpeg.Decode(bytes.NewReader(data))
+	if err != nil {
+		t.Fatalf("saved file is not valid JPEG: %v", err)
+	}
+
+	gotW, gotH := img.Bounds().Dx(), img.Bounds().Dy()
+	if gotW != thumbW || gotH != thumbH {
+		t.Errorf("thumbnail dimensions %dx%d, want %dx%d", gotW, gotH, thumbW, thumbH)
+	}
+}

thumbs/kfx/reader.go

@@ -0,0 +1,67 @@
+package mobi_test
+
+import (
+	"bytes"
+	"image/jpeg"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"go.uber.org/zap/zaptest"
+
+	"s2k/thumbs/mobi"
+)
+
+const testFile = "../../testdata/_Test.azw3"
+
+func TestNewReader(t *testing.T) {
+	if _, err := os.Stat(testFile); err != nil {
+		t.Skipf("test fixture not available: %v", err)
+	}
+
+	log := zaptest.NewLogger(t)
+
+	const thumbW, thumbH = 330, 470
+
+	r, err := mobi.NewReader(testFile, thumbW, thumbH, log)
+	if err != nil {
+		t.Fatalf("NewReader failed: %v", err)
+	}
+
+	dir := t.TempDir()
+	name, err := r.SaveResult(dir)
+	if err != nil {
+		t.Fatalf("SaveResult failed: %v", err)
+	}
+	if name == "" {
+		t.Fatal("SaveResult returned empty filename — no thumbnail was extracted")
+	}
+
+	t.Logf("saved thumbnail: %s", name)
+
+	// Verify the file is a valid JPEG with expected dimensions.
+	data, err := os.ReadFile(filepath.Join(dir, name))
+	if err != nil {
+		t.Fatalf("unable to read saved thumbnail: %v", err)
+	}
+
+	// SOI marker.
+	if len(data) < 2 || data[0] != 0xFF || data[1] != 0xD8 {
+		t.Fatal("saved file does not start with JPEG SOI marker")
+	}
+
+	// JFIF APP0 segment must be present (Kindle requirement).
+	if len(data) < 4 || data[2] != 0xFF || data[3] != 0xE0 {
+		t.Fatal("saved file does not contain JFIF APP0 segment")
+	}
+
+	img, err := jpeg.Decode(bytes.NewReader(data))
+	if err != nil {
+		t.Fatalf("saved file is not valid JPEG: %v", err)
+	}
+
+	gotW, gotH := img.Bounds().Dx(), img.Bounds().Dy()
+	if gotW != thumbW || gotH != thumbH {
+		t.Errorf("thumbnail dimensions %dx%d, want %dx%d", gotW, gotH, thumbW, thumbH)
+	}
+}