MIL-002: Step 1 - User interface

Review record RC-024 (Go, autonomous mode, not independent).

Task: MIL-002#1
Task: MIL-002#2
Task: MIL-002#3
Task: MIL-002#4

tests/unit/test_app.py

@@ -1,11 +1,27 @@
 """Tests of the entry point.
 
 @file test_app.py
-@brief Checks main of flash_card.presentation.app.
+@brief Checks main of flash_card.presentation.app without opening a window.
 """
 
-from flash_card.presentation.app import main
+import pytest
+
+from flash_card.presentation import app
 
 
-def test_main_returns_zero_without_arguments() -> None:
-    assert main([]) == 0
+class _FakeRoot:
+    def __init__(self) -> None:
+        self.mainloop_calls = 0
+
+    def mainloop(self) -> None:
+        self.mainloop_calls += 1
+
+
+def test_main_runs_main_loop_and_returns_zero(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    root = _FakeRoot()
+    monkeypatch.setattr(app, "create_application", lambda: (root, object()))
+
+    assert app.main([]) == 0
+    assert root.mainloop_calls == 1

tests/unit/test_flash_card_view_model.py

@@ -0,0 +1,18 @@
+"""Tests of the flash card view model.
+
+@file test_flash_card_view_model.py
+@brief Checks the placeholder texts of FlashCardViewModel.
+"""
+
+from flash_card.constants import PLACEHOLDER_LANGUAGE_NAME, PLACEHOLDER_WORD
+from flash_card.presentation.features.flash_card.flash_card_view_model import (
+    FlashCardViewModel,
+)
+
+
+def test_language_name_returns_placeholder() -> None:
+    assert FlashCardViewModel().language_name == PLACEHOLDER_LANGUAGE_NAME
+
+
+def test_text_returns_placeholder_word() -> None:
+    assert FlashCardViewModel().text == PLACEHOLDER_WORD

tests/unit/test_generate_images.py

@@ -0,0 +1,58 @@
+"""Tests of the image generator tool.
+
+@file test_generate_images.py
+@brief Checks the PNG files written by tools/generate_images.py.
+"""
+
+import importlib.util
+import struct
+from pathlib import Path
+from types import ModuleType
+
+import pytest
+
+from flash_card.constants import (
+    CARD_BACK_IMAGE_NAME,
+    CARD_FRONT_IMAGE_NAME,
+    CARD_HEIGHT,
+    CARD_WIDTH,
+    RIGHT_IMAGE_NAME,
+    WRONG_IMAGE_NAME,
+)
+
+_TOOL_PATH = Path(__file__).resolve().parents[2] / "tools" / "generate_images.py"
+_SIGNATURE = b"\x89PNG\r\n\x1a\n"
+
+
+def _load_tool() -> ModuleType:
+    spec = importlib.util.spec_from_file_location("generate_images", _TOOL_PATH)
+    assert spec is not None
+    assert spec.loader is not None
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+@pytest.fixture(scope="module")
+def generated(tmp_path_factory: pytest.TempPathFactory) -> Path:
+    output_dir = tmp_path_factory.mktemp("assets")
+    assert _load_tool().main(["--output-dir", str(output_dir)]) == 0
+    return output_dir
+
+
+@pytest.mark.parametrize(
+    ("name", "width", "height"),
+    [
+        (CARD_FRONT_IMAGE_NAME, CARD_WIDTH, CARD_HEIGHT),
+        (CARD_BACK_IMAGE_NAME, CARD_WIDTH, CARD_HEIGHT),
+        (RIGHT_IMAGE_NAME, 100, 100),
+        (WRONG_IMAGE_NAME, 100, 100),
+    ],
+)
+def test_generate_images_writes_png_with_expected_size(
+    generated: Path, name: str, width: int, height: int
+) -> None:
+    data = (generated / name).read_bytes()
+    assert data.startswith(_SIGNATURE)
+    assert data[12:16] == b"IHDR"
+    assert struct.unpack(">II", data[16:24]) == (width, height)