Add test coverage

dev_requirements.txt

@@ -1,2 +1,3 @@
 pytest>=8.0
+pytest-cov>=5.0
 black>=24.0

pyproject.toml

@@ -29,13 +29,15 @@ dependencies = [
 [project.optional-dependencies]
 test = [
     "pytest>=8.0",
+    "pytest-cov>=5.0",
 ]
 dev = [
     "black>=24.0",
     "pylint>=3.3",
     "mypy>=1.10",
     "pyright>=1.1",
     "pytest>=8.0",
+    "pytest-cov>=5.0",
 ]
 
 [tool.setuptools]
@@ -55,6 +57,12 @@ py-version = "3.10"
 [tool.pylint.format]
 max-line-length = 120
 
+[tool.coverage.run]
+source = ["microsoft"]
+
+[tool.coverage.report]
+show_missing = true
+
 [tool.pylint.messages_control]
 disable = [
     "missing-function-docstring",

src/microsoft/opentelemetry/_azure_monitor/_browser_sdk_loader/django_middleware.py

@@ -42,7 +42,8 @@ def __init__(self, get_response: Callable[[HttpRequest], HttpResponse]) -> None:
         :type get_response: Callable[[HttpRequest], HttpResponse]
         :rtype: None
         """
-        super().__init__(get_response)
+        if MiddlewareMixin is not object:
+            super().__init__(get_response)
         self.get_response = get_response
         self._injector: Optional[WebSnippetInjector] = None
         if not DJANGO_AVAILABLE:

tests/azure_monitor/browserSdkLoader/test_init.py

@@ -0,0 +1,190 @@
+# -------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for
+# license information.
+# --------------------------------------------------------------------------
+
+import unittest
+from unittest.mock import MagicMock, patch
+
+from microsoft.opentelemetry._azure_monitor._browser_sdk_loader._config import BrowserSDKConfig
+
+_MW_PATH = (
+    "microsoft.opentelemetry._azure_monitor._browser_sdk_loader"
+    ".django_middleware.ApplicationInsightsWebSnippetMiddleware"
+)
+
+
+class TestSetupSnippetInjection(unittest.TestCase):
+    def setUp(self):
+        self.config = BrowserSDKConfig(
+            enabled=True,
+            connection_string="InstrumentationKey=test;IngestionEndpoint=https://test.in.ai.azure.com/",
+        )
+
+    @patch("microsoft.opentelemetry._azure_monitor._browser_sdk_loader._setup_django_injection")
+    def test_setup_snippet_injection_calls_django(self, mock_django):
+        from microsoft.opentelemetry._azure_monitor._browser_sdk_loader import setup_snippet_injection
+
+        setup_snippet_injection(self.config)
+        mock_django.assert_called_once_with(self.config)
+
+    @patch(
+        "microsoft.opentelemetry._azure_monitor._browser_sdk_loader._setup_django_injection",
+        side_effect=Exception("boom"),
+    )
+    def test_setup_snippet_injection_handles_exception(self, mock_django):
+        from microsoft.opentelemetry._azure_monitor._browser_sdk_loader import setup_snippet_injection
+
+        # Should not raise
+        setup_snippet_injection(self.config)
+
+
+class TestSetupDjangoInjection(unittest.TestCase):
+    def setUp(self):
+        self.config = BrowserSDKConfig(
+            enabled=True,
+            connection_string="InstrumentationKey=test;IngestionEndpoint=https://test.in.ai.azure.com/",
+        )
+
+    @patch.dict("sys.modules", {"django": None, "django.conf": None})
+    def test_django_not_available(self):
+        from microsoft.opentelemetry._azure_monitor._browser_sdk_loader import _setup_django_injection
+
+        # Should not raise when django is not importable
+        _setup_django_injection(self.config)
+
+    @patch("microsoft.opentelemetry._azure_monitor._browser_sdk_loader._register_django_middleware")
+    def test_django_available_and_configured(self, mock_register):
+        settings_mock = MagicMock()
+        settings_mock.configured = True
+
+        with patch.dict(
+            "sys.modules",
+            {
+                "django": MagicMock(),
+                "django.conf": MagicMock(settings=settings_mock),
+            },
+        ):
+            from microsoft.opentelemetry._azure_monitor._browser_sdk_loader import _setup_django_injection
+
+            _setup_django_injection(self.config)
+            mock_register.assert_called_once_with(self.config)
+
+    def test_django_not_configured(self):
+        settings_mock = MagicMock()
+        settings_mock.configured = False
+
+        with patch.dict(
+            "sys.modules",
+            {
+                "django": MagicMock(),
+                "django.conf": MagicMock(settings=settings_mock),
+            },
+        ):
+            from microsoft.opentelemetry._azure_monitor._browser_sdk_loader import _setup_django_injection
+
+            # Should return early without raising
+            _setup_django_injection(self.config)
+
+
+class TestRegisterDjangoMiddleware(unittest.TestCase):
+    def setUp(self):
+        self.config = BrowserSDKConfig(
+            enabled=True,
+            connection_string="InstrumentationKey=test;IngestionEndpoint=https://test.in.ai.azure.com/",
+        )
+
+    def test_register_with_middleware_attr(self):
+        settings_mock = MagicMock(spec_set=["MIDDLEWARE"])
+        settings_mock.MIDDLEWARE = ["django.middleware.common.CommonMiddleware"]
+
+        with patch.dict(
+            "sys.modules",
+            {
+                "django": MagicMock(),
+                "django.conf": MagicMock(settings=settings_mock),
+            },
+        ):
+            from microsoft.opentelemetry._azure_monitor._browser_sdk_loader import _register_django_middleware
+
+            _register_django_middleware(self.config)
+            # Our middleware should have been appended
+            middleware_list = settings_mock.MIDDLEWARE
+            self.assertIn(_MW_PATH, middleware_list)
+
+    def test_register_with_middleware_classes_attr(self):
+        settings_mock = MagicMock(spec=[])
+        settings_mock.MIDDLEWARE_CLASSES = ["django.middleware.common.CommonMiddleware"]
+
+        with patch.dict(
+            "sys.modules",
+            {
+                "django": MagicMock(),
+                "django.conf": MagicMock(settings=settings_mock),
+            },
+        ):
+            from microsoft.opentelemetry._azure_monitor._browser_sdk_loader import _register_django_middleware
+
+            _register_django_middleware(self.config)
+            self.assertIn(_MW_PATH, settings_mock.MIDDLEWARE_CLASSES)
+
+    def test_already_registered(self):
+        middleware_path = _MW_PATH
+        settings_mock = MagicMock()
+        settings_mock.MIDDLEWARE = [middleware_path]
+
+        with patch.dict(
+            "sys.modules",
+            {
+                "django": MagicMock(),
+                "django.conf": MagicMock(settings=settings_mock),
+            },
+        ):
+            from microsoft.opentelemetry._azure_monitor._browser_sdk_loader import _register_django_middleware
+
+            _register_django_middleware(self.config)
+            # Should not duplicate
+            self.assertEqual(settings_mock.MIDDLEWARE.count(middleware_path), 1)
+
+
+class TestStoreDjangoConfig(unittest.TestCase):
+    def setUp(self):
+        self.config = BrowserSDKConfig(
+            enabled=True,
+            connection_string="InstrumentationKey=test;IngestionEndpoint=https://test.in.ai.azure.com/",
+        )
+
+    def test_store_config(self):
+        settings_mock = MagicMock(spec=[])
+        # No AZURE_MONITOR_WEB_SNIPPET_CONFIG attribute yet
+
+        with patch.dict(
+            "sys.modules",
+            {
+                "django": MagicMock(),
+                "django.conf": MagicMock(settings=settings_mock),
+            },
+        ):
+            from microsoft.opentelemetry._azure_monitor._browser_sdk_loader import _store_django_config
+
+            _store_django_config(self.config)
+            self.assertEqual(settings_mock.AZURE_MONITOR_WEB_SNIPPET_CONFIG, self.config)
+
+    def test_store_config_already_set(self):
+        existing_config = BrowserSDKConfig(enabled=False)
+        settings_mock = MagicMock()
+        settings_mock.AZURE_MONITOR_WEB_SNIPPET_CONFIG = existing_config
+
+        with patch.dict(
+            "sys.modules",
+            {
+                "django": MagicMock(),
+                "django.conf": MagicMock(settings=settings_mock),
+            },
+        ):
+            from microsoft.opentelemetry._azure_monitor._browser_sdk_loader import _store_django_config
+
+            _store_django_config(self.config)
+            # Should not overwrite
+            self.assertEqual(settings_mock.AZURE_MONITOR_WEB_SNIPPET_CONFIG, existing_config)