Use a separate folder for ANSI art for tests; add more gallery tests

src/textual_paint/gallery.py

@@ -26,7 +26,7 @@ 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')
 dev_options.add_argument('--restart-on-changes', action='store_true', help='Restart the app when the source code is changed')
 
-args = parser.parse_args()
+args = parser.parse_args(os.environ.get("PYTEST_GALLERY_ARGS", "").split() or None)
 
 def _(text: str) -> str:
     """Placeholder for localization function."""

tests/samples_for_gallery_app_tests/clippy.ans

@@ -0,0 +1,10 @@
+    ▀▀▀        
+    ▀ ▀        
+  ▀▀▀ ▀▀▀      
+   ▀_/_▀_______
+    / _ ______ 
+  _ _ _ _____  
+  _ _▀ ▀_ ▀▀▀  
+  _ ____ ▀__   
+ _/▀ ▀▀ ▀___   
+_/_________    

tests/samples_for_gallery_app_tests/scroll_and_candle.ans

@@ -0,0 +1,24 @@
+===__====_=======___======____=__========____========_==============_)__========
+=======_______========▀▄▄ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀=====___(░==========
+===____=====__=======   ░░          \  \######/      /      ▀▀=__===)=======____
+==_=\=====__===__===     ░░          \###### /   #  /         =====(░)______====
+_//==\\\=_=========     ▀▀▀     ▒      \ ▒  /       |      ▒▀▀====((__\=======__
+//(O))_\_=====\=__=     ░░  ▒▒▒▒▒▒▒   ▒/▒  /       /     ▒▒▀▀====__=♠=)====_____
+\\\==//========__==    ░▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀===\__=(=♠=))=__===__
+=_\\/____=====__===     ░░▒▒▓ %\SSSSSSSSSSSSSSSSSSSSSS =======_==(=♠♠♠_)_==___==
+==_======____======          ⌂ %\SSSSSSSSSSSSSSSSSSSS =====___=====_♠_)==__\====
+========__==__=======     _____  %%%%\SSSSSSSSS/%%%%\S ===_=========⌠===_=====__
+=======___====_========= /▲▲▲▲▲\_     %%%%%%%%% ⌂⌂⌂  % ==__===_==_♣ ▀  _====__==
+=====____====__====     /▲▲    ▲▲\   Ye olde.          ======_=__=   ▌\\=___====
+=____==_====__=====             ▲▲▲     Just a fact. ========__==/▌  ▌)))======_
+_====__==___==\\===   /           ▲▲  ▲ ▲ ########\   ========__((⌡  ▌////_____=
+===__=____====__=== --             ▲▲ ▲▲▲##########\   ======___===   ▌/_=======
+=___=__=======__===  =   X                  _ - -###\  =======((((   ▌ ))))=====
+__=\_=======__========     - _           _ -      ## ======(((        ▌    )))==
+=___========_======  / / _      -_     _-   ¡ ¡!¡!  == ===(           ▌       )_
+==========__=▀▀▀▀▀▀ ≈≈≈≈≈Θ>        - _-    !¡!¡!¡¡!  ░ ==(        ▌    ▌       )
+========__== ░░░░░▒  \ \                            ░▒ ===(         ▌         )=
+======__=== ░▒▒▒▒  ▓░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░▒▀▀====(((             )))__
+===____==== ▒▒▒▒  ▓▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▓▀▀======))((((    )))))))= =
+___=========     =- @1j01                 -=-=-===▀▀===__=====))))))))))))  === 
+=============▀  ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀====__======_==___________   =

tests/test_snapshots.py

@@ -3,6 +3,7 @@
 Run with `pytest tests/test_snapshots.py`, or `pytest` to run all tests.
 """
 
+import os
 from pathlib import Path, PurePath
 from typing import TYPE_CHECKING, Awaitable, Callable, Iterable, Protocol
 
@@ -309,6 +310,27 @@ def test_fill_spiral(snap_compare: SnapCompareType):
 
     assert snap_compare(PAINT, run_before=automate_app, terminal_size=LARGER)
 
-def test_gallery_app(snap_compare: SnapCompareType):
+def test_gallery_app_small_art_centered(snap_compare: SnapCompareType):
+    os.environ["PYTEST_GALLERY_ARGS"] = "./tests/samples_for_gallery_app_tests"
     assert snap_compare(GALLERY)
 
+def test_gallery_app_big_art_with_scrollbars(snap_compare: SnapCompareType):
+    os.environ["PYTEST_GALLERY_ARGS"] = "./tests/samples_for_gallery_app_tests"
+    assert snap_compare(GALLERY, press=["right"])
+
+def test_gallery_app_nonexistent_folder(snap_compare: SnapCompareType):
+    os.environ["PYTEST_GALLERY_ARGS"] = "./tests/this_folder_does_not_exist"
+    # TODO: test app exit with error message
+    # could spy on `app.exit` or try to listen for an exit event if there is one
+    # or make a separate test that runs the CLI directly and checks stderr
+    assert snap_compare(GALLERY, press=["right", "left"]) # arrow keys shouldn't cause errors
+
+def test_gallery_app_empty_folder(snap_compare: SnapCompareType):
+    os.environ["PYTEST_GALLERY_ARGS"] = "./tests/empty_folder"
+    # Create the empty folder since Git doesn't track empty folders.
+    os.makedirs("./tests/empty_folder", exist_ok=True)
+    assert snap_compare(GALLERY, press=["right", "left"]) # arrow keys shouldn't cause errors
+
+def test_gallery_app_file_path(snap_compare: SnapCompareType):
+    os.environ["PYTEST_GALLERY_ARGS"] = "./tests/samples_for_gallery_app_tests/scroll_and_candle.ans"
+    assert snap_compare(GALLERY, press=["right", "left"]) # arrow keys shouldn't cause errors