import unittest import os import shutil import sys from ebooklib import epub # Ensure import path sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))) from abogen.book_parser import get_book_parser class TestEpubHeuristicNav(unittest.TestCase): """ Tests for the heuristic fallback in _identify_nav_item (Step 4), where the parser scans ITEM_DOCUMENTs for

when no explicit ITEM_NAVIGATION is found. """ def setUp(self): self.test_dir = "tests/test_data_heuristic" if os.path.exists(self.test_dir): shutil.rmtree(self.test_dir) os.makedirs(self.test_dir) self.epub_path = os.path.join(self.test_dir, "heuristic_test.epub") def tearDown(self): if os.path.exists(self.test_dir): shutil.rmtree(self.test_dir) def test_heuristic_nav_discovery(self): book = epub.EpubBook() book.set_identifier("heuristic123") book.set_title("Heuristic Test Book") # 1. Add Content c1 = epub.EpubHtml(title="Chapter 1", file_name="chap1.xhtml", lang="en") c1.content = "

Chapter 1

Text

" book.add_item(c1) # 2. Add a Nav file BUT as a regular EpubHtml (ITEM_DOCUMENT) # We do NOT use EpubNav. We do NOT look like a standard nav file if possible, # but content must contain the magical signature. nav_content = """ """ # Filename intentionally generic/obscure to avoid filename-based heuristics # (though current code checks content, not just filename) nav_file = epub.EpubHtml(title="Hidden Nav", file_name="content_toc.xhtml") nav_file.content = nav_content book.add_item(nav_file) # 3. Setup Spine book.spine = [nav_file, c1] # 4. Write EPUB epub.write_epub(self.epub_path, book) # 5. Patch OPF to ensure ebooklib didn't sneakily add ITEM_NAVIGATION or toc="ncx" import zipfile patched = False with zipfile.ZipFile(self.epub_path, "r") as zin: opf_content = zin.read("EPUB/content.opf").decode("utf-8") # Remove toc="ncx" attribute if present (causes crash if no NCX) if 'toc="ncx"' in opf_content: opf_content = opf_content.replace('toc="ncx"', "") patched = True # Ideally we'd verify properties="nav" isn't there, but EpubHtml shouldn't add it. # If ebooklib added it, we might need to strip it to force heuristic. if 'properties="nav"' in opf_content: opf_content = opf_content.replace('properties="nav"', "") patched = True if patched: TEMP_EPUB = self.epub_path + ".temp" with zipfile.ZipFile(TEMP_EPUB, "w") as zout: for item in zin.infolist(): if item.filename == "EPUB/content.opf": zout.writestr(item, opf_content) else: zout.writestr(item, zin.read(item.filename)) if patched: shutil.move(TEMP_EPUB, self.epub_path) # 6. Verify our setup: Ensure NO ITEM_NAVIGATION exists # We can inspect using ebooklib again import ebooklib check_book = epub.read_epub(self.epub_path) nav_items = list(check_book.get_items_of_type(ebooklib.ITEM_NAVIGATION)) self.assertEqual( len(nav_items), 0, "Setup failed: explicit navigation item found!" ) # 7. Run Parser parser = get_book_parser(self.epub_path) parser.process_content() chapters = parser.get_chapters() # 8. Assertions # Should have found the nav via content scanning chapter_titles = [c[1] for c in chapters] self.assertIn("Chapter 1", chapter_titles) # Also verify we hit the "html" type in identification # We can't easily check private variables, but success implies it worked. if __name__ == "__main__": unittest.main()