pptx-image-compress/test_pptx_image_compress.py

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()