comments with calculations in the tests

from review, adding the calculations in comments with the tests helps to make the arithmetic more credible

#1098 (review)

www/__tests__/footprintHelper.test.ts

@@ -38,24 +38,38 @@ const custom_metrics = [
   { key: 'unicycle', values: 5000 },
 ];
 
+/*
+  3*0 + 6.5*0 + 10*0.22031 + 25*0.00894 + 5*0
+  0 + 0 + 2.2031 + 0.2235 + 0
+  2.4266
+*/
 it('gets footprint for metrics (custom, fallback 0)', async () => {
   const appConfig = await getConfig();
   await initCustomDatasetHelper(appConfig);
   expect(getFootprintForMetrics(custom_metrics, 0)).toBe(2.4266);
 });
 
+/*
+  3*0 + 6.5*0 + 10*0.22031 + 25*0.00894 + 5*0.1
+  0 + 0 + 2.2031 + 0.2235 + 0.5
+  2.4266 + 0.5
+*/
 it('gets footprint for metrics (custom, fallback 0.1)', async () => {
   const appConfig = await getConfig();
   await initCustomDatasetHelper(appConfig);
   expect(getFootprintForMetrics(custom_metrics, 0.1)).toBe(2.4266 + 0.5);
 });
 
+//expects TAXI from the fake labels
 it('gets the highest footprint from the dataset, custom', async () => {
   const appConfig = await getConfig();
   await initCustomDatasetHelper(appConfig);
   expect(getHighestFootprint()).toBe(0.30741);
 });
 
+/*
+  TAXI co2/km * meters/1000
+*/
 it('gets the highest footprint for distance, custom', async () => {
   const appConfig = await getConfig();
   await initCustomDatasetHelper(appConfig);

www/__tests__/metHelper.test.ts

@@ -22,19 +22,19 @@ global.fetch = (url: string) =>
   }) as any;
 
 it('gets met for mode and speed', () => {
-  expect(getMet('WALKING', 1.47523, 0)).toBe(4.3);
-  expect(getMet('BICYCLING', 4.5, 0)).toBe(6.8);
-  expect(getMet('UNICYCLE', 100, 0)).toBe(0);
-  expect(getMet('CAR', 25, 1)).toBe(0);
+  expect(getMet('WALKING', 1.47523, 0)).toBe(4.3); //1.47523 mps = 3.299 mph -> 4.3 METs
+  expect(getMet('BICYCLING', 4.5, 0)).toBe(6.8); //4.5 mps = 10.07 mph =  6.8 METs
+  expect(getMet('UNICYCLE', 100, 0)).toBe(0); //unkown mode, 0 METs
+  expect(getMet('CAR', 25, 1)).toBe(0); //0 METs in CAR
 });
 
 it('gets custom met for mode and speed', async () => {
   const appConfig = await getConfig();
   await initCustomDatasetHelper(appConfig);
-  expect(getMet('walk', 1.47523, 0)).toBe(4.3);
-  expect(getMet('bike', 4.5, 0)).toBe(6.8);
-  expect(getMet('unicycle', 100, 0)).toBe(0);
-  expect(getMet('drove_alone', 25, 1)).toBe(0);
-  expect(getMet('e-bike', 6, 1)).toBe(4.9);
-  expect(getMet('e-bike', 12, 1)).toBe(4.9);
+  expect(getMet('walk', 1.47523, 0)).toBe(4.3); //1.47523 mps = 3.299 mph -> 4.3 METs
+  expect(getMet('bike', 4.5, 0)).toBe(6.8); //4.5 mps = 10.07 mph =  6.8 METs
+  expect(getMet('unicycle', 100, 0)).toBe(0); //unkown mode, 0 METs
+  expect(getMet('drove_alone', 25, 1)).toBe(0); //0 METs IN_VEHICLE
+  expect(getMet('e-bike', 6, 1)).toBe(4.9); //e-bike is 4.9 for all speeds
+  expect(getMet('e-bike', 12, 1)).toBe(4.9); //e-bike is 4.9 for all speeds
 });