test: Add comprehensive pytest suite for core components

Author: PyCompiler ARK++

Tests/test_suite.py

@@ -0,0 +1,101 @@
+# SPDX-License-Identifier: Apache-2.0
+# Basic pytest suite covering core components without launching the GUI loop
+
+import os
+import types
+import importlib
+
+import pytest
+
+
+@pytest.fixture(autouse=True)
+def _ensure_offscreen_qt(monkeypatch):
+    # Make Qt use an offscreen backend to avoid display/server requirements during import
+    monkeypatch.setenv("QT_QPA_PLATFORM", os.environ.get("QT_QPA_PLATFORM", "offscreen"))
+    monkeypatch.setenv("PYTHONUTF8", "1")
+    monkeypatch.setenv("PYTHONIOENCODING", "utf-8")
+
+
+def test_core_version_and_api_import():
+    # Import Core public package and ensure version exists and API snapshot can be materialized
+    Core = importlib.import_module("Core")
+    assert hasattr(Core, "__version__")
+    assert isinstance(Core.__version__, str) and len(Core.__version__) > 0
+
+    # Access lazy API snapshot (triggers internal lazy loads where possible)
+    api = getattr(Core, "api")
+    assert isinstance(api, dict)
+    assert "ui" in api
+
+
+def test_core_clear_lazy_caches_idempotent():
+    Core = importlib.import_module("Core")
+    # Should not raise and be idempotent
+    assert hasattr(Core, "_clear_lazy_caches")
+    Core._clear_lazy_caches()
+    Core._clear_lazy_caches()
+
+
+def test_engines_registry_register_and_create():
+    registry = importlib.import_module("Core.engines_loader.registry")
+    base = importlib.import_module("Core.engines_loader.base")
+
+    class DummyEngine(base.CompilerEngine):
+        id = "dummy-test-engine"
+        name = "DummyTestEngine"
+
+        def build_command(self, gui, file: str):
+            return ["python", "-c", "print('ok')"]
+
+    # Ensure clean slate for this id
+    registry.unregister(DummyEngine.id)
+
+    # Register
+    engine_cls = registry.register(DummyEngine)
+    assert engine_cls is DummyEngine
+    assert DummyEngine.id in registry.available_engines()
+
+    # get_engine
+    looked_up = registry.get_engine(DummyEngine.id)
+    assert looked_up is DummyEngine
+
+    # create returns instance
+    inst = registry.create(DummyEngine.id)
+    assert isinstance(inst, DummyEngine)
+
+    # Unregister should remove it from listing and lookup
+    registry.unregister(DummyEngine.id)
+    assert DummyEngine.id not in registry.available_engines()
+    assert registry.get_engine(DummyEngine.id) is None
+
+
+def test_base_engine_program_and_args_split():
+    base = importlib.import_module("Core.engines_loader.base")
+
+    class E(base.CompilerEngine):
+        id = "splitter"
+
+        def build_command(self, gui, file: str):
+            return ["python", "-m", "pip", "--version"]
+
+    e = E()
+    prog, args = e.program_and_args(gui=None, file="x.py")
+    assert prog == "python"
+    assert args[:2] == ["-m", "pip"]
+
+
+def test_deps_analyser_stdlib_detection():
+    analyser = importlib.import_module("Core.deps_analyser.analyser")
+    is_std = getattr(analyser, "_is_stdlib_module")
+
+    assert is_std("sys") is True
+    assert is_std("json") is True
+    # A very unlikely third-party module name should not be detected as stdlib
+    assert is_std("this_module_name_should_not_exist_12345") is False
+
+
+def test_main_module_imports_and_has_main():
+    # Importing main should not execute the app because __main__ guard prevents that
+    m = importlib.import_module("main")
+    assert hasattr(m, "main") and isinstance(m.main, types.FunctionType)
+    # Do not call main() here to avoid starting a Qt event loop in tests