Re-structure the project.

tests/pdf/test_detector.py

@@ -0,0 +1,335 @@
+"""
+Tests for the PDF Type Detection Module.
+
+Tests cover all detector functions in src/pdf/detector.py
+
+Note: These tests require PyMuPDF (fitz) and actual PDF files or mocks.
+Some tests are marked as integration tests that require real PDF files.
+
+Usage:
+    pytest src/pdf/test_detector.py -v -o 'addopts='
+"""
+
+import pytest
+from pathlib import Path
+from unittest.mock import patch, MagicMock
+from src.pdf.detector import (
+    extract_text_first_page,
+    is_text_pdf,
+    get_pdf_type,
+    get_page_info,
+    PDFType,
+)
+
+
+class TestExtractTextFirstPage:
+    """Tests for extract_text_first_page function."""
+
+    def test_with_mock_empty_pdf(self):
+        """Should return empty string for empty PDF."""
+        mock_doc = MagicMock()
+        mock_doc.__len__ = MagicMock(return_value=0)
+
+        with patch("fitz.open", return_value=mock_doc):
+            result = extract_text_first_page("test.pdf")
+            assert result == ""
+
+    def test_with_mock_text_pdf(self):
+        """Should extract text from first page."""
+        mock_page = MagicMock()
+        mock_page.get_text.return_value = "Faktura 12345\nDatum: 2025-01-15"
+
+        mock_doc = MagicMock()
+        mock_doc.__len__ = MagicMock(return_value=1)
+        mock_doc.__getitem__ = MagicMock(return_value=mock_page)
+
+        with patch("fitz.open", return_value=mock_doc):
+            result = extract_text_first_page("test.pdf")
+            assert "Faktura" in result
+            assert "12345" in result
+
+
+class TestIsTextPDF:
+    """Tests for is_text_pdf function."""
+
+    def test_empty_pdf_returns_false(self):
+        """Should return False for PDF with no text."""
+        with patch("src.pdf.detector.extract_text_first_page", return_value=""):
+            assert is_text_pdf("test.pdf") is False
+
+    def test_short_text_returns_false(self):
+        """Should return False for PDF with very short text."""
+        with patch("src.pdf.detector.extract_text_first_page", return_value="Hello"):
+            assert is_text_pdf("test.pdf") is False
+
+    def test_readable_text_with_keywords_returns_true(self):
+        """Should return True for readable text with invoice keywords."""
+        text = """
+        Faktura
+        Datum: 2025-01-15
+        Belopp: 1234,56 SEK
+        Bankgiro: 5393-9484
+        Moms: 25%
+        """ + "a" * 200  # Ensure > 200 chars
+
+        with patch("src.pdf.detector.extract_text_first_page", return_value=text):
+            assert is_text_pdf("test.pdf") is True
+
+    def test_garbled_text_returns_false(self):
+        """Should return False for garbled/unreadable text."""
+        # Simulate garbled text (lots of non-printable characters)
+        garbled = "\x00\x01\x02" * 100 + "abc" * 20  # Low readable ratio
+
+        with patch("src.pdf.detector.extract_text_first_page", return_value=garbled):
+            assert is_text_pdf("test.pdf") is False
+
+    def test_text_without_keywords_needs_high_readability(self):
+        """Should require high readability when no keywords found."""
+        # Text without invoice keywords
+        text = "The quick brown fox jumps over the lazy dog. " * 10
+
+        with patch("src.pdf.detector.extract_text_first_page", return_value=text):
+            # Should pass if readable ratio is high enough
+            result = is_text_pdf("test.pdf")
+            # Result depends on character ratio - ASCII text should pass
+            assert result is True
+
+    def test_custom_min_chars(self):
+        """Should respect custom min_chars parameter."""
+        text = "Short text here"  # 15 chars
+
+        with patch("src.pdf.detector.extract_text_first_page", return_value=text):
+            # Default min_chars=30 - should fail
+            assert is_text_pdf("test.pdf", min_chars=30) is False
+            # Custom min_chars=10 - should pass basic length check
+            # (but will still fail keyword/readability checks)
+
+
+class TestGetPDFType:
+    """Tests for get_pdf_type function."""
+
+    def test_empty_pdf_returns_scanned(self):
+        """Should return 'scanned' for empty PDF."""
+        mock_doc = MagicMock()
+        mock_doc.__len__ = MagicMock(return_value=0)
+
+        with patch("fitz.open", return_value=mock_doc):
+            result = get_pdf_type("test.pdf")
+            assert result == "scanned"
+
+    def test_all_text_pages_returns_text(self):
+        """Should return 'text' when all pages have text."""
+        mock_page1 = MagicMock()
+        mock_page1.get_text.return_value = "A" * 50  # > 30 chars
+
+        mock_page2 = MagicMock()
+        mock_page2.get_text.return_value = "B" * 50  # > 30 chars
+
+        mock_doc = MagicMock()
+        mock_doc.__len__ = MagicMock(return_value=2)
+        mock_doc.__iter__ = MagicMock(return_value=iter([mock_page1, mock_page2]))
+
+        with patch("fitz.open", return_value=mock_doc):
+            result = get_pdf_type("test.pdf")
+            assert result == "text"
+
+    def test_no_text_pages_returns_scanned(self):
+        """Should return 'scanned' when no pages have text."""
+        mock_page1 = MagicMock()
+        mock_page1.get_text.return_value = ""
+
+        mock_page2 = MagicMock()
+        mock_page2.get_text.return_value = "AB"  # < 30 chars
+
+        mock_doc = MagicMock()
+        mock_doc.__len__ = MagicMock(return_value=2)
+        mock_doc.__iter__ = MagicMock(return_value=iter([mock_page1, mock_page2]))
+
+        with patch("fitz.open", return_value=mock_doc):
+            result = get_pdf_type("test.pdf")
+            assert result == "scanned"
+
+    def test_mixed_pages_returns_mixed(self):
+        """Should return 'mixed' when some pages have text."""
+        mock_page1 = MagicMock()
+        mock_page1.get_text.return_value = "A" * 50  # Has text
+
+        mock_page2 = MagicMock()
+        mock_page2.get_text.return_value = ""  # No text
+
+        mock_doc = MagicMock()
+        mock_doc.__len__ = MagicMock(return_value=2)
+        mock_doc.__iter__ = MagicMock(return_value=iter([mock_page1, mock_page2]))
+
+        with patch("fitz.open", return_value=mock_doc):
+            result = get_pdf_type("test.pdf")
+            assert result == "mixed"
+
+
+class TestGetPageInfo:
+    """Tests for get_page_info function."""
+
+    def test_single_page_pdf(self):
+        """Should return info for single page."""
+        mock_rect = MagicMock()
+        mock_rect.width = 595.0  # A4 width in points
+        mock_rect.height = 842.0  # A4 height in points
+
+        mock_page = MagicMock()
+        mock_page.get_text.return_value = "A" * 50
+        mock_page.rect = mock_rect
+
+        mock_doc = MagicMock()
+        mock_doc.__len__ = MagicMock(return_value=1)
+
+        def mock_iter(self):
+            yield mock_page
+        mock_doc.__iter__ = lambda self: mock_iter(self)
+
+        with patch("fitz.open", return_value=mock_doc):
+            pages = get_page_info("test.pdf")
+
+            assert len(pages) == 1
+            assert pages[0]["page_no"] == 0
+            assert pages[0]["width"] == 595.0
+            assert pages[0]["height"] == 842.0
+            assert pages[0]["has_text"] is True
+            assert pages[0]["char_count"] == 50
+
+    def test_multi_page_pdf(self):
+        """Should return info for all pages."""
+        def create_mock_page(text, width, height):
+            mock_rect = MagicMock()
+            mock_rect.width = width
+            mock_rect.height = height
+
+            mock_page = MagicMock()
+            mock_page.get_text.return_value = text
+            mock_page.rect = mock_rect
+            return mock_page
+
+        pages_data = [
+            ("A" * 50, 595.0, 842.0),  # Page 0: has text
+            ("", 595.0, 842.0),         # Page 1: no text
+            ("B" * 100, 612.0, 792.0),  # Page 2: different size, has text
+        ]
+
+        mock_pages = [create_mock_page(*data) for data in pages_data]
+
+        mock_doc = MagicMock()
+        mock_doc.__len__ = MagicMock(return_value=3)
+
+        def mock_iter(self):
+            for page in mock_pages:
+                yield page
+        mock_doc.__iter__ = lambda self: mock_iter(self)
+
+        with patch("fitz.open", return_value=mock_doc):
+            pages = get_page_info("test.pdf")
+
+            assert len(pages) == 3
+
+            # Page 0
+            assert pages[0]["page_no"] == 0
+            assert pages[0]["has_text"] is True
+            assert pages[0]["char_count"] == 50
+
+            # Page 1
+            assert pages[1]["page_no"] == 1
+            assert pages[1]["has_text"] is False
+            assert pages[1]["char_count"] == 0
+
+            # Page 2
+            assert pages[2]["page_no"] == 2
+            assert pages[2]["has_text"] is True
+            assert pages[2]["width"] == 612.0
+
+
+class TestPDFTypeAnnotation:
+    """Tests for PDFType type alias."""
+
+    def test_valid_types(self):
+        """PDFType should accept valid literal values."""
+        # These are compile-time checks, but we can verify at runtime
+        valid_types: list[PDFType] = ["text", "scanned", "mixed"]
+        assert all(t in ["text", "scanned", "mixed"] for t in valid_types)
+
+
+class TestIsTextPDFKeywordDetection:
+    """Tests for keyword detection in is_text_pdf."""
+
+    def test_detects_swedish_keywords(self):
+        """Should detect Swedish invoice keywords."""
+        keywords = [
+            ("faktura", True),
+            ("datum", True),
+            ("belopp", True),
+            ("bankgiro", True),
+            ("plusgiro", True),
+            ("moms", True),
+        ]
+
+        for keyword, expected in keywords:
+            # Create text with keyword and enough content
+            text = f"Document with {keyword} keyword here" + " more text" * 50
+
+            with patch("src.pdf.detector.extract_text_first_page", return_value=text):
+                # Need at least 2 keywords for is_text_pdf to return True
+                # So this tests if keyword is recognized when combined with others
+                pass
+
+    def test_detects_english_keywords(self):
+        """Should detect English invoice keywords."""
+        text = "Invoice document with date and amount information" + " x" * 100
+
+        with patch("src.pdf.detector.extract_text_first_page", return_value=text):
+            # invoice + date = 2 keywords
+            result = is_text_pdf("test.pdf")
+            assert result is True
+
+    def test_needs_at_least_two_keywords(self):
+        """Should require at least 2 keywords to pass keyword check."""
+        # Only one keyword
+        text = "This is a faktura document" + " x" * 200
+
+        with patch("src.pdf.detector.extract_text_first_page", return_value=text):
+            # With only 1 keyword, falls back to other checks
+            # Should still pass if readability is high
+            pass
+
+
+class TestReadabilityChecks:
+    """Tests for readability ratio checks in is_text_pdf."""
+
+    def test_high_ascii_ratio_passes(self):
+        """Should pass when ASCII ratio is high."""
+        # Pure ASCII text
+        text = "This is a normal document with only ASCII characters. " * 10
+
+        with patch("src.pdf.detector.extract_text_first_page", return_value=text):
+            result = is_text_pdf("test.pdf")
+            assert result is True
+
+    def test_swedish_characters_accepted(self):
+        """Should accept Swedish characters as readable."""
+        text = "Fakturadatum för årets moms på öre belopp" + " normal" * 50
+
+        with patch("src.pdf.detector.extract_text_first_page", return_value=text):
+            result = is_text_pdf("test.pdf")
+            assert result is True
+
+    def test_low_readability_fails(self):
+        """Should fail when readability ratio is too low."""
+        # Mix of readable and unreadable characters
+        # Create text with < 70% readable characters
+        readable = "abc" * 30  # 90 readable chars
+        unreadable = "\x80\x81\x82" * 50  # 150 unreadable chars
+        text = readable + unreadable
+
+        with patch("src.pdf.detector.extract_text_first_page", return_value=text):
+            result = is_text_pdf("test.pdf")
+            assert result is False
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v"])