Refactor and UnitTest

test_pptx_image_compress.py

@@ -0,0 +1,144 @@
+import tempfile
+import unittest
+import zipfile
+from pathlib import Path
+
+import pptx_image_compress as pic
+
+
+class TestPptxImageCompress(unittest.TestCase):
+    def test_discover_images_filters_extensions(self):
+        with tempfile.TemporaryDirectory() as td:
+            media_dir = Path(td)
+            (media_dir / "a.jpg").write_bytes(b"1")
+            (media_dir / "b.png").write_bytes(b"1")
+            (media_dir / "c.txt").write_bytes(b"1")
+            (media_dir / "d.GIF").write_bytes(b"1")
+            images = pic.discover_images(media_dir)
+            self.assertEqual([p.name for p in images], ["a.jpg", "b.png", "d.GIF"])
+
+    def test_image_result_to_log_line(self):
+        image_result = pic.ImageProcessResult(
+            image_name="image1.png",
+            orig_size=1000,
+            chosen_size=800,
+            slide_nr="[1, 2]",
+        )
+        line = pic.image_result_to_log_line(image_result)
+        self.assertIn("image1.png", line)
+        self.assertIn("[1, 2]", line)
+        self.assertIn("20.0", line)
+
+    def test_process_image_file_replaces_when_smaller(self):
+        with tempfile.TemporaryDirectory() as td:
+            root = Path(td)
+            img = root / "image1.png"
+            img.write_bytes(b"A" * 100)
+            scratch = root / "scratch"
+
+            def fake_compressor(original: Path, out_dir: Path, caesium_threads: int | None, quality: int, min_savings: str):
+                out_dir.mkdir(parents=True, exist_ok=True)
+                out = out_dir / original.name
+                out.write_bytes(b"B" * 40)
+                return out
+
+            result = pic.process_image_file(
+                idx=1,
+                img_path=img,
+                scratch_dir=scratch,
+                image_to_slides={"image1.png": [1]},
+                caesium_threads=1,
+                quality=90,
+                min_savings="2%",
+                compressor=fake_compressor,
+            )
+
+            self.assertEqual(result.chosen_size, 40)
+            self.assertEqual(img.stat().st_size, 40)
+            self.assertEqual(result.slide_nr, "[1]")
+
+    def test_process_image_file_keeps_original_when_bigger(self):
+        with tempfile.TemporaryDirectory() as td:
+            root = Path(td)
+            img = root / "image1.png"
+            img.write_bytes(b"A" * 100)
+            scratch = root / "scratch"
+
+            def fake_compressor(original: Path, out_dir: Path, caesium_threads: int | None, quality: int, min_savings: str):
+                out_dir.mkdir(parents=True, exist_ok=True)
+                out = out_dir / original.name
+                out.write_bytes(b"B" * 120)
+                return out
+
+            result = pic.process_image_file(
+                idx=1,
+                img_path=img,
+                scratch_dir=scratch,
+                image_to_slides={},
+                caesium_threads=1,
+                quality=90,
+                min_savings="2%",
+                compressor=fake_compressor,
+            )
+
+            self.assertEqual(result.chosen_size, 100)
+            self.assertEqual(img.stat().st_size, 100)
+            self.assertEqual(result.slide_nr, "NOT_USED")
+
+    def test_process_single_deck_with_injected_compressor(self):
+        with tempfile.TemporaryDirectory() as td:
+            root = Path(td)
+            input_pptx = root / "input.pptx"
+            output_pptx = root / "output.pptx"
+            source_tree = root / "src"
+            rels_dir = source_tree / "ppt" / "slides" / "_rels"
+            media_dir = source_tree / "ppt" / "media"
+            rels_dir.mkdir(parents=True, exist_ok=True)
+            media_dir.mkdir(parents=True, exist_ok=True)
+
+            rels_xml = (
+                "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>"
+                "<Relationships xmlns=\"http://schemas.openxmlformats.org/package/2006/relationships\">"
+                "<Relationship Id=\"rId2\" Type=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships/image\" Target=\"../media/image1.png\"/>"
+                "</Relationships>"
+            )
+            (rels_dir / "slide1.xml.rels").write_text(rels_xml, encoding="utf-8")
+            (media_dir / "image1.png").write_bytes(b"A" * 100)
+
+            with zipfile.ZipFile(input_pptx, "w", compression=zipfile.ZIP_DEFLATED) as z:
+                for p in source_tree.rglob("*"):
+                    if p.is_file():
+                        z.write(p, arcname=str(p.relative_to(source_tree)))
+
+            def fake_compressor(original: Path, out_dir: Path, caesium_threads: int | None, quality: int, min_savings: str):
+                out_dir.mkdir(parents=True, exist_ok=True)
+                out = out_dir / original.name
+                out.write_bytes(b"B" * 50)
+                return out
+
+            result = pic.process_single_deck(
+                input_pptx=input_pptx,
+                output_pptx=output_pptx,
+                threads=2,
+                quality=90,
+                min_savings="2%",
+                compressor=fake_compressor,
+            )
+
+            self.assertTrue(result.ok)
+            self.assertEqual(result.error, None)
+            self.assertTrue(output_pptx.exists())
+            self.assertIsNotNone(result.log_file)
+            with zipfile.ZipFile(output_pptx, "r") as z:
+                out_image = z.read("ppt/media/image1.png")
+            self.assertEqual(len(out_image), 50)
+            log_file = result.log_file
+            if log_file is None:
+                self.fail("log_file should not be None")
+            log_text = Path(log_file).read_text(encoding="utf-8")
+            self.assertIn("image1.png", log_text)
+            self.assertIn("[1]", log_text)
+
+
+if __name__ == "__main__":
+    unittest.main()