MIL-003: Step 2 - New flash cards

Review record RC-025 (Go, autonomous mode, not independent).

Task: MIL-003#1
Task: MIL-003#2
Task: MIL-003#3
Task: MIL-003#4
Task: MIL-003#5

tests/unit/test_app.py

@@ -4,6 +4,8 @@
 @brief Checks main of flash_card.presentation.app without opening a window.
 """
 
+from pathlib import Path
+
 import pytest
 
 from flash_card.presentation import app
@@ -18,10 +20,24 @@ class _FakeRoot:
 
 
 def test_main_runs_main_loop_and_returns_zero(
-    monkeypatch: pytest.MonkeyPatch,
+    monkeypatch: pytest.MonkeyPatch, tmp_path: Path
 ) -> None:
     root = _FakeRoot()
-    monkeypatch.setattr(app, "create_application", lambda: (root, object()))
+    seen: list[Path | None] = []
 
-    assert app.main([]) == 0
+    def fake_create(data_dir: Path | None = None) -> tuple[_FakeRoot, object]:
+        seen.append(data_dir)
+        return root, object()
+
+    monkeypatch.setattr(app, "create_application", fake_create)
+
+    assert app.main(["--data-dir", str(tmp_path)]) == 0
     assert root.mainloop_calls == 1
+    assert seen == [tmp_path]
+
+
+def test_main_returns_one_when_word_list_is_missing(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    assert app.main(["--data-dir", str(tmp_path / "nowhere")]) == 1
+    assert "word list not found" in caplog.text