Fix incorrect Likelihood of Stop chart if some races have no stops. (#362)

Author: simonkagwi

frontend/src/Components/Charts/SearchRate/SearchRate.js

@@ -94,7 +94,13 @@ function SearchRate(props) {
           DEMOGRAPHICS_COLORS.other,
         ];
         const data = {
-          labels: ['Black', 'Hispanic', 'Asian', 'Native American', 'Other'],
+          labels: res.data.stop_percentages_races || [
+            'Black',
+            'Hispanic',
+            'Asian',
+            'Native American',
+            'Other',
+          ],
           datasets: [
             {
               axis: 'y',

nc/tests/api/test_stop_search_rate.py

@@ -393,6 +393,7 @@ def test_agency_stop_counts_by_year(self, client, durham, year_2020):
         # Stop rate ratio should be 0.6 for black drivers, or black drivers are
         # 60% more likely to be pulled over than white drivers
         assert data["stop_percentages"] == [0.62]
+        assert data["stop_percentages_races"] == ["Black"]
         table_data = data["table_data"]
         # Two rows for white and black drivers
         assert len(table_data) == 2
@@ -438,6 +439,7 @@ def test_more_and_less_likelihood_of_stops(self, client, durham, year_2020):
         assert response.status_code == 200
         data = response.json()
         assert data["stop_percentages"] == [1.69, -0.35]
+        assert data["stop_percentages_races"] == ["Black", "Asian"]
         table_data = data["table_data"]
         # Three rows for white, black, and asian drivers
         assert len(table_data) == 3
@@ -490,3 +492,4 @@ def test_no_acs_data_empty_stop_percentages(self, client, durham, year_2020):
         # When no ACS data exists, stop_percentages should be empty
         assert data["stop_percentages"] == []
         assert data["table_data"] == []
+        assert "stop_percentages_races" not in data

nc/views/likelihood.py

@@ -159,4 +159,11 @@ def get(self, request, agency_id):
             "stop_percentages": stop_percentages,
             "table_data": table_data.to_dict(orient="records"),
         }
+
+        if stop_percentages and len(stop_percentages) < 5:
+            # We have stop percentages, but not for all races. Add the list of
+            # races with stop percentages to the response, so we'll know which
+            # ones to display in the chart on the frontend
+            data["stop_percentages_races"] = chart_df["race"]
+
         return Response(data=data, status=200)