Fix to return proper results when variables with 0 value are passed into function

Author: fershad

src/co2.test.js

@@ -947,7 +947,7 @@ describe("co2", () => {
   });
 
   describe("Using values equal to 0", () => {
-    const co2 = new CO2();
+    const co2 = new CO2({ results: "segment" });
 
     it("expects perByteTrace to support values equal to 0", () => {
       const perByteTraceResult = co2.perByteTrace(1000000, false, {
@@ -986,5 +986,77 @@ describe("co2", () => {
       expect(network).toBe(0);
       expect(device).toBe(0);
     });
+    it("expects perByteTrace segments to be 0 when grid intensity is 0", () => {
+      const perByteTraceResult = co2.perByteTrace(1000000, false, {
+        gridIntensity: {
+          dataCenter: 0,
+          network: 0,
+          device: 0,
+        },
+      });
+      const co2Result = perByteTraceResult.co2;
+      // Less than 0.1 because there's still a small production component that's calculated
+      expect(co2Result.total).toBeLessThan(0.1);
+      expect(co2Result["dataCenterCO2"]).toBe(0);
+      expect(co2Result["networkCO2"]).toBe(0);
+      expect(co2Result["consumerDeviceCO2"]).toBe(0);
+    });
+
+    it("expects perVisitTrace segments to be 0 when grid intensity is 0", () => {
+      const perVisitTraceResult = co2.perVisitTrace(1000000, false, {
+        gridIntensity: {
+          dataCenter: 0,
+          network: 0,
+          device: 0,
+        },
+      });
+      const co2Result = perVisitTraceResult.co2;
+      const { dataCenter, network, device } =
+        perVisitTraceResult.variables.gridIntensity;
+      // Less than 0.1 because there's still a small production component that's calculated
+      expect(co2Result.total).toBeLessThan(0.1);
+      expect(co2Result["dataCenterCO2 - first"]).toBe(0);
+      expect(co2Result["networkCO2 - first"]).toBe(0);
+      expect(co2Result["consumerDeviceCO2 - first"]).toBe(0);
+      expect(co2Result["dataCenterCO2 - subsequent"]).toBe(0);
+      expect(co2Result["networkCO2 - subsequent"]).toBe(0);
+      expect(co2Result["consumerDeviceCO2 - subsequent"]).toBe(0);
+    });
+
+    it("expects perVisitTrace segments to be 0 when there are 0 first and returning visitors", () => {
+      const perVisitTraceResult = co2.perVisitTrace(1000000, false, {
+        firstVisitPercentage: 0,
+        returnVisitPercentage: 0,
+      });
+      const co2Result = perVisitTraceResult.co2;
+      // Less than 0.1 because there's still a small production component that's calculated
+      expect(co2Result.total).toBe(0);
+    });
+
+    it("expects perVisitTrace subsequent segments to be 0 when returning visitors is 0", () => {
+      const perVisitTraceResult = co2.perVisitTrace(1000000, false, {
+        firstVisitPercentage: 100,
+        returnVisitPercentage: 0,
+      });
+      const co2Result = perVisitTraceResult.co2;
+      expect(co2Result["dataCenterCO2 - first"]).toBeGreaterThan(0);
+      expect(co2Result["networkCO2 - first"]).toBeGreaterThan(0);
+      expect(co2Result["consumerDeviceCO2 - first"]).toBeGreaterThan(0);
+      expect(co2Result["dataCenterCO2 - subsequent"]).toBe(0);
+      expect(co2Result["networkCO2 - subsequent"]).toBe(0);
+      expect(co2Result["consumerDeviceCO2 - subsequent"]).toBe(0);
+    });
+    it("expects perVisitTrace subsequent segments to be 0 when data reload is 0", () => {
+      const perVisitTraceResult = co2.perVisitTrace(1000000, false, {
+        dataReloadRatio: 0,
+      });
+      const co2Result = perVisitTraceResult.co2;
+      expect(co2Result["dataCenterCO2 - first"]).toBeGreaterThan(0);
+      expect(co2Result["networkCO2 - first"]).toBeGreaterThan(0);
+      expect(co2Result["consumerDeviceCO2 - first"]).toBeGreaterThan(0);
+      expect(co2Result["dataCenterCO2 - subsequent"]).toBe(0);
+      expect(co2Result["networkCO2 - subsequent"]).toBe(0);
+      expect(co2Result["consumerDeviceCO2 - subsequent"]).toBe(0);
+    });
   });
 });

src/sustainable-web-design.js

@@ -70,14 +70,14 @@ class SustainableWebDesign {
     if (options?.gridIntensity) {
       const { device, network, dataCenter } = options.gridIntensity;
 
-      if (device?.value) {
+      if (device?.value || device?.value === 0) {
         deviceCarbonIntensity = device.value;
       }
-      if (network?.value) {
+      if (network?.value || network?.value === 0) {
         networkCarbonIntensity = network.value;
       }
       // If the user has set a carbon intensity value for the datacentre, then that overrides everything and is used
-      if (dataCenter?.value) {
+      if (dataCenter?.value || dataCenter?.value === 0) {
         dataCenterCarbonIntensity = dataCenter.value;
       }
     }
@@ -245,15 +245,15 @@ class SustainableWebDesign {
     returnView = RETURNING_VISITOR_PERCENTAGE,
     dataReloadRatio = PERCENTAGE_OF_DATA_LOADED_ON_SUBSEQUENT_LOAD
   ) {
-    if (options.dataReloadRatio) {
+    if (options.dataReloadRatio || options.dataReloadRatio === 0) {
       dataReloadRatio = options.dataReloadRatio;
     }
 
-    if (options.firstVisitPercentage) {
+    if (options.firstVisitPercentage || options.firstVisitPercentage === 0) {
       firstView = options.firstVisitPercentage;
     }
 
-    if (options.returnVisitPercentage) {
+    if (options.returnVisitPercentage || options.returnVisitPercentage === 0) {
       returnView = options.returnVisitPercentage;
     }