add optional argument 'mode_key' to calc_footprint_for_trip

This will allow the footprint to be calculated for a trip using either the mode_confirm or the replaced_mode_confirm.

Expanded the tests to demonstrate how this would be used to determine the "impact" of the ebike in a trip where ebike replaces car.
- changed expacted values to 3 decimal places because ebikes are so efficient the values would round to 0.00

src/emcommon/metrics/footprint/footprint_calculations.py

@@ -11,13 +11,13 @@
 import emcommon.metrics.footprint.util as emcmfu
 
 
-async def calc_footprint_for_trip(trip, label_options, mode_value=None, labels_map=None):
+async def calc_footprint_for_trip(trip, label_options, mode_key='mode', mode_value=None, labels_map=None):
     """
     Calculate the estimated footprint of a trip, which includes 'kwh' and 'kg_co2' fields.
     """
     trip = dict(trip)
     # Log.debug(f"Getting footprint for trip: {str(trip)}")
-    mode_value = mode_value or emcdu.label_for_trip(trip, 'mode', labels_map)
+    mode_value = mode_value or emcdu.label_for_trip(trip, mode_key, labels_map)
     rich_mode = mode_value and emcdb.get_rich_mode_for_value(mode_value, label_options)
     is_uncertain = False
     if rich_mode is None or 'footprint' not in rich_mode:

src/emcommon/metrics/metrics_summaries.py

@@ -73,6 +73,7 @@ async def value_of_metric_for_trip(metric_name: str, grouping_field: str, groupi
     elif metric_name == 'footprint':
         (footprint, metadata) = await emcmff.calc_footprint_for_trip(trip,
                                                                      app_config['label_options'],
+                                                                     'mode',
                                                                      grouping_val,
                                                                      labels_map)
         footprint.update({'metadata': metadata})

test/metrics/test_footprint_calculations.py

@@ -5,7 +5,7 @@
 
 
 @jest_test
-async def test_car_default_footprint():
+async def test_car_footprint():
     """
     Test kWh and kg CO2e for a 1 km trip in the default CAR.
     """
@@ -24,22 +24,47 @@ async def test_car_default_footprint():
 
     (footprint, metadata) = await emcmff.calc_footprint_for_trip(fake_trip, fake_label_options)
 
-    expected_footprint = {'kwh': 0.90, 'kg_co2': 0.29}
+    expected_footprint = {'kwh': 0.899, 'kg_co2': 0.291}
     for key in expected_footprint.keys():
-        expectAlmostEqual(footprint[key], expected_footprint[key], delta=0.01)
+        expectAlmostEqual(footprint[key], expected_footprint[key], delta=0.001)
 
     # with 2 passengers, the footprint should be halved
     fake_label_options['MODE'][0]['passengers'] = 2
 
     (footprint, metadata) = await emcmff.calc_footprint_for_trip(fake_trip, fake_label_options)
 
-    expected_footprint = {'kwh': 0.90 / 2, 'kg_co2': 0.29 / 2}
+    expected_footprint = {'kwh': 0.899 / 2, 'kg_co2': 0.291 / 2}
     for key in expected_footprint.keys():
-        expectAlmostEqual(footprint[key], expected_footprint[key], delta=0.01)
+        expectAlmostEqual(footprint[key], expected_footprint[key], delta=0.001)
 
 
 @jest_test
-async def test_car_custom_footprint():
+async def test_ebike_footprint():
+    """
+    Test kWh and kg CO2e for a 1 km trip in the default E_BIKE.
+    """
+    fake_trip = {
+        "_id": "fake_trip_id",
+        "distance": 1000,
+        "start_fmt_time": "0000-00-00T00:00:00",
+        "start_loc": {"coordinates": [0, 0]},
+        "user_input": {"mode_confirm": "ebike"}
+    }
+    fake_label_options = {
+        "MODE": [
+            {"value": "ebike", "base_mode": "E_BIKE"}
+        ]
+    }
+
+    (footprint, metadata) = await emcmff.calc_footprint_for_trip(fake_trip, fake_label_options)
+
+    expected_footprint = {'kwh': 0.014, 'kg_co2': 0.006}
+    for key in expected_footprint.keys():
+        expectAlmostEqual(footprint[key], expected_footprint[key], delta=0.001)
+
+
+@jest_test
+async def test_custom_car_footprint():
     """
     Test kWh and kg CO2e for a 10 km trip in a custom CAR (wh/km = 100).
     """
@@ -100,4 +125,39 @@ async def test_nyc_bus_footprint():
         expectEqual(metadata[key], expected_metadata[key])
 
 
+@jest_test
+async def test_impact_of_ebike_replacing_car():
+    """
+    Test kWh and kg CO2e saved for a 1 km trip where E_BIKE replaced CAR.
+    """
+    fake_trip = {
+        "_id": "fake_trip_id",
+        "distance": 1000,
+        "start_fmt_time": "0000-00-00T00:00:00",
+        "start_loc": {"coordinates": [0, 0]},
+        "user_input": {"mode_confirm": "ebike", "replaced_mode_confirm": "car"}
+    }
+    fake_label_options = {
+        "MODE": [
+            {"value": "car", "base_mode": "CAR"},
+            {"value": "ebike", "base_mode": "E_BIKE"}
+        ]
+    }
+
+    (mode_footprint, metadata) = await emcmff.calc_footprint_for_trip(
+        fake_trip,
+        fake_label_options
+    )
+    (replaced_mode_footprint, metadata) = await emcmff.calc_footprint_for_trip(
+        fake_trip,
+        fake_label_options,
+        'replaced_mode'
+    )
+    kwh_saved = replaced_mode_footprint['kwh'] - mode_footprint['kwh']
+    kg_co2_saved = replaced_mode_footprint['kg_co2'] - mode_footprint['kg_co2']
+
+    expectAlmostEqual(kwh_saved, 0.885, delta=0.001)
+    expectAlmostEqual(kg_co2_saved, 0.285, delta=0.001)
+
+
 jest_describe("test_footprint_calculations")