Add tests for Aussie Broadband diagnostics (#113049)

* Add tests for diag

* Fix docstring

* Spelling

tests/components/aussie_broadband/snapshots/test_diagnostics.ambr

@@ -0,0 +1,40 @@
+# serializer version: 1
+# name: test_select_async_setup_entry
+  dict({
+    'services': list([
+      dict({
+        'service': dict({
+          'coordinator': '**REDACTED**',
+          'description': '**REDACTED**',
+          'name': 'NBN',
+          'service_id': '12345678',
+          'type': 'NBN',
+        }),
+        'usage': dict({
+        }),
+      }),
+      dict({
+        'service': dict({
+          'coordinator': '**REDACTED**',
+          'description': '**REDACTED**',
+          'name': 'Mobile',
+          'service_id': '87654321',
+          'type': 'PhoneMobile',
+        }),
+        'usage': dict({
+        }),
+      }),
+      dict({
+        'service': dict({
+          'coordinator': '**REDACTED**',
+          'description': '**REDACTED**',
+          'name': 'VOIP',
+          'service_id': '23456789',
+          'type': 'VOIP',
+        }),
+        'usage': dict({
+        }),
+      }),
+    ]),
+  })
+# ---

tests/components/aussie_broadband/test_diagnostics.py

@@ -0,0 +1,22 @@
+"""Test the Aussie Broadband Diagnostics."""
+
+from syrupy.assertion import SnapshotAssertion
+
+from homeassistant.core import HomeAssistant
+
+from .common import setup_platform
+
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+from tests.typing import ClientSessionGenerator
+
+
+async def test_select_async_setup_entry(
+    hass: HomeAssistant,
+    hass_client: ClientSessionGenerator,
+    snapshot: SnapshotAssertion,
+) -> None:
+    """Test diagnostics platform."""
+
+    entry = await setup_platform(hass, [])
+    diag = await get_diagnostics_for_config_entry(hass, hass_client, entry)
+    assert diag == snapshot