VS Code Dev Container (dev & test environment) (#605)

* build: dev container

Add a VS Code Dev Container from the blueprint at bceaae212f

* build: dev container test setup

Add support for unit testing in the dev container environment with debugging and code coverage.

* ci: adjust to dev container test restructuring

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* ci: fix coverage collection

* build: add dummy light to HA config

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* build: update dev container to Python 3.11 (for HA 2023.6)

* Add VS Code tasks

* Use pre-commit hooks for linting

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Unpin HA version

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Bas Nijholt <basnijholt@gmail.com>

tests/conftest.py

@@ -0,0 +1,19 @@
+"""Fixtures for testing."""
+import os
+import sys
+
+import pytest
+
+# Tests in the dev enviromentment use the pytest_homeassistant_custom_component instead of
+# a cloned HA core repo for a simple and clean structure. To still test against a HA core
+# clone (e.g. the dev branch for which no pytest_homeassistant_custom_component exists
+# because HA does not publish dev snapshot packages), set the HA_CLONE env variable.
+if "HA_CLONE" in os.environ:
+    # Rewire the testing package to the cloned test modules. See the test `Dockerfile`
+    # for setup details.
+    sys.modules["pytest_homeassistant_custom_component"] = __import__("tests")
+
+
+@pytest.fixture(autouse=True)
+def auto_enable_custom_integrations(enable_custom_integrations):
+    yield