Move --recode-samples to an automated test

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Removed
+
+- `--recode-samples` option is removed, now covered by the `pytest` test suite.
+
 ### Changed
 
 - Made radio buttons rounder in `--ascii-only` mode, using parentheses instead of square brackets.

README.md

@@ -87,7 +87,6 @@ development options:
   --clear-screen        Clear the screen before starting, to avoid seeing
                         outdated errors
   --restart-on-changes  Restart the app when the source code is changed
-  --recode-samples      Open and save each file in samples/, for testing
 ```
 
 ### Keyboard Shortcuts
@@ -329,22 +328,6 @@ This also makes it run slower.
 
 Often it's useful to exclude events with `textual console -x EVENT`.
 
-<details>
-<summary>Testing file save/load roundtrip</summary>
-
-> There are at this point lots of files that will change if you run this, so don't worry about it. Some are generated files, so they naturally change somewhat. The `0x0.ans` file saves as 1x1, due to the minimum size. `pathological_character_grid.svg` was free-handed with Inkscape, so naturally changes somewhat when re-saving. There may be actual problems, but they're hard to spot in the noise.
-
-To test file encoding, run `textual run --dev "src.textual_paint.paint --recode-samples"`.
-
-If there are differences in the ANSI files, you can set up a special diff like this:
-```bash
-git config --local "diff.cat-show-all.textconv" "cat --show-all"
-```
-but you should check that `cat --show-all samples/2x2.ans` works on your system first.
-Also, note that it might not work with your Git GUI of choice; you may need to use the command line.
-
-</details>
-
 ### Troubleshooting
 
 > `Unable to import 'app' from module 'src.textual_paint.paint'`
@@ -373,7 +356,7 @@ PYRIGHT_PYTHON_FORCE_VERSION=1.1.318 pyright
 # I also tried mypy and fixed some errors it reported, but I'm not targeting zero errors with mypy.
 mypy src --no-namespace-packages --check-untyped-defs
 
-# Visual Regression Testing
+# Visual Regression Testing (and a few other tests)
 # I use pytest-textual-snapshot, which is a pytest plugin for comparing SVG screenshots of Textual apps over time.
 pytest
 # To accept differences, update the baseline with:

src/textual_paint/args.py

@@ -18,6 +18,7 @@ parser.add_argument('--ascii-only', action='store_true', help='Use only ASCII ch
 parser.add_argument('--backup-folder', default=None, metavar="FOLDER", help='Folder to save backups to. By default a backup is saved alongside the edited file.')
 
 # TODO: hide development options from help? there's quite a few of them now
+# (...actually, less of them now, and I've grouped them together)
 dev_options = parser.add_argument_group('development options')
 dev_options.add_argument('--inspect-layout', action='store_true', help='Enables DOM inspector (F12) and middle click highlight')
 # This flag is important for my sanity during development,
@@ -27,7 +28,6 @@ dev_options.add_argument('--inspect-layout', action='store_true', help='Enables
 # I really don't want false ones mixed in. You want to reward your brain for finding good solutions, after all.
 dev_options.add_argument('--clear-screen', action='store_true', help='Clear the screen before starting, to avoid seeing outdated errors')
 dev_options.add_argument('--restart-on-changes', action='store_true', help='Restart the app when the source code is changed')
-dev_options.add_argument('--recode-samples', action='store_true', help='Open and save each file in samples/, for testing')
 
 parser.add_argument('filename', nargs='?', default=None, help='Path to a file to open. File will be created if it doesn\'t exist.')
 

src/textual_paint/paint.py

@@ -4131,42 +4131,6 @@ else:
     # This requires the canvas to exist, hence call_later().
     app.call_later(app.recover_from_backup)
 
-if args.recode_samples:
-    # Re-encode the sample files to test for changes/inconsistency in encoding.
-
-    async def recode_sample(file_path: str|Path) -> None:
-        """Re-encodes a single sample file."""
-        print(f"Re-encoding {file_path}")
-        with open(file_path, "rb") as f:
-            image = AnsiArtDocument.decode_based_on_file_extension(f.read(), str(file_path))
-        with open(file_path, "wb") as f:
-            f.write(image.encode_based_on_file_extension(str(file_path)))
-        print(f"Saved {file_path}")
-
-    async def recode_samples() -> None:
-        """Re-encodes all sample files in parallel."""
-        samples_folder = os.path.join(os.path.dirname(__file__), "../../samples")
-        tasks: list[Coroutine[Any, Any, None]] = []
-        for file_path in Path(samples_folder).glob("**/*"):
-            # Skip backup files in case some sample file is being edited.
-            if file_path.name.endswith("~"):
-                continue
-            # Skip GIMP Palette files.
-            if file_path.name.endswith(".gpl"):
-                continue
-            # Skip folders.
-            if file_path.is_dir():
-                continue
-            tasks.append(recode_sample(file_path))
-
-        await asyncio.gather(*tasks)
-
-    # have to wait for the app to be initialized
-    async def once_running() -> None:
-        await recode_samples()
-        app.exit()
-    app.call_later(once_running)
-
 if args.clear_screen:
     os.system("cls||clear")
 

tests/test_encoding.py

@@ -0,0 +1,31 @@
+"""Test that files are encoded correctly."""
+
+from pathlib import Path
+import pytest
+
+from textual_paint.ansi_art_document import AnsiArtDocument
+
+ROUND_TRIP_EXCLUSIONS = [
+    # These files are generated by a script, not the Textual Paint app, so they naturally change.
+    "4x4_font_template.ans",
+    "gradient_test.ans",
+    # This one was free-handed with Inkscape, so naturally changes a lot.
+    "pathological_character_grid.svg",
+    # The `0x0.ans` file saves as 1x1, due to the minimum size.
+    "0x0.ans",
+    # This is a color palette file, meant to be loaded with Get Colors, not Open.
+    "pipe_strip_palette.gpl",
+    # THIS ONE MAYBE SHOULD IDEALLY WORK? But I need a better way of viewing a diff...
+    "cp437_as_utf8.txt",
+]
+SAMPLES_DIR = Path(__file__).parent.parent / "samples"
+SAMPLES = [f for f in SAMPLES_DIR.iterdir() if f.is_file() and "~" not in f.name]
+ROUND_TRIP_SAMPLES = [f for f in SAMPLES if f.name not in ROUND_TRIP_EXCLUSIONS]
+
+@pytest.mark.parametrize("file_path", ROUND_TRIP_SAMPLES)
+def test_round_trip(file_path: Path) -> None:
+    """Test that files are re-encoded identically when opened and saved."""
+    with open(file_path, "rb") as f:
+        file_content = f.read()
+        image = AnsiArtDocument.decode_based_on_file_extension(file_content, str(file_path))
+        assert image.encode_based_on_file_extension(str(file_path)) == file_content