fix: report repo mix context failures (#103)

tests/test_widgets.py

@@ -1,8 +1,15 @@
+import json
+import subprocess
+from pathlib import Path
+
 import pytest
 
 from src.views import dashboard
 
 
+WIDGETS = Path(__file__).parents[1] / "frontend" / "widgets.js"
+
+
 @pytest.mark.anyio
 async def test_dashboard_renders_repo_mix_placeholder_before_javascript_runs():
     html = await dashboard()
@@ -16,3 +23,25 @@ async def test_dashboard_marks_fallback_context_as_degraded_instead_of_live():
     html = await dashboard()
 
     assert "data.error ? 'Degraded · ' + data.error : 'Live · updated just now'" in html
+
+
+def test_repo_mix_reports_unavailable_for_failed_context_response():
+    script = f"""
+const updateRepoMix = require({json.dumps(str(WIDGETS))});
+const element = {{ innerHTML: 'stale counts' }};
+const failedFetch = async () => ({{
+  ok: false,
+  status: 503,
+  json: async () => ({{ error: 'upstream unavailable' }}),
+}});
+
+updateRepoMix(element, failedFetch).then(() => {{
+  if (!element.innerHTML.includes('Widget unavailable.')) {{
+    throw new Error(`expected unavailable state, got: ${{element.innerHTML}}`);
+  }}
+}});
+"""
+
+    subprocess.run(
+        ["node", "-e", script], check=True, capture_output=True, text=True
+    )