Fix load fixture (#42)

* add failing test

* fix load_fixture manually

* automatically modify load_fixture

* test that fixture data is loaded

* add information to README

* update CHANGELOG

CHANGELOG.md

@@ -1,6 +1,11 @@
 # Changelog
 This changelog only includes changes directly related to the structure of this project. Changes in testing behavior may still occur from changes in homeassistant/core.
 
+Changes to minor version indicate a change structurally in this pacakge.  Changes in patch indicate changes solely from homeassistant/core. The latter does not imply no breaking changes are introduced.
+
+## 0.2.0
+* fix `load_fixture`
+
 ## 0.1.0
 * remove Python 3.7 and add Python 3.9
 * remove `async_test`

README.md

@@ -11,6 +11,14 @@ The goal is to provide the same functionality as the tests in home-assistant/cor
   * home-assistant/core native test: `from tests.common import MockConfigEntry`
   * custom component test: `from pytest_homeassistant_custom_component.common import MockConfigEntry`
 * If your integration is inside a `custom_components` folder, a `custom_components/__init__.py` file or changes to `sys.path` may be required.
+* If using `load_fixture`, the files need to be in a `fixtures` folder colocated with the tests. For example, a test in `test_sensor.py` can load data from `some_data.json` using `load_fixture` from this structure:
+
+```
+tests/
+   fixtures/
+      some_data.json
+   test_sensor.py
+```
 
 ## Examples:
 * See [list of custom components](https://github.com/MatthewFlamm/pytest-homeassistant-custom-component/network/dependents) as examples that use this package.

generate_package.py

@@ -129,3 +129,20 @@
     new_file.write("".join(data))
 
 print(f"Version: {__version__}")
+
+
+# modify load_fixture
+with open(os.path.join(PACKAGE_DIR, "common.py"), "r") as original_file:
+    data = original_file.readlines()
+
+import_time_lineno = [i for i, line in enumerate(data) if "from time" in line]
+assert len(import_time_lineno) == 1
+data.insert(import_time_lineno[0] + 1, "import traceback\n")
+
+load_fixture_lineno = [i for i, line in enumerate(data) if "load_fixture" in line]
+assert len(load_fixture_lineno) == 1
+data.insert(load_fixture_lineno[0] + 2, "    start_path = traceback.extract_stack()[-2].filename\n")
+data[load_fixture_lineno[0] + 3] = data[load_fixture_lineno[0] + 3].replace("__file__", "start_path")
+
+with open(os.path.join(PACKAGE_DIR, "common.py"), "w") as new_file:
+    new_file.writelines(data)

pytest_homeassistant_custom_component/common.py

@@ -17,6 +17,7 @@
 import threading
 import time
 from time import monotonic
+import traceback
 import types
 from typing import Any, Awaitable, Collection, Optional
 from unittest.mock import AsyncMock, Mock, patch
@@ -399,7 +400,8 @@ def async_fire_service_discovered(hass, service, info):
 
 def load_fixture(filename):
     """Load a fixture."""
-    path = os.path.join(os.path.dirname(__file__), "fixtures", filename)
+    start_path = traceback.extract_stack()[-2].filename
+    path = os.path.join(os.path.dirname(start_path), "fixtures", filename)
     with open(path, encoding="utf-8") as fptr:
         return fptr.read()
 

tests/fixtures/test_data.json

@@ -0,0 +1,3 @@
+{
+    "test_key": "test_value"
+}

tests/test_common.py

@@ -0,0 +1,9 @@
+"""Tests changes to common module."""
+import json
+
+from pytest_homeassistant_custom_component.common import load_fixture
+
+
+def test_load_fixture():
+    data = json.loads(load_fixture("test_data.json"))
+    assert data == {"test_key": "test_value"}