Merge 95ab429f08 into 2b2ff0b883

CHANGELOG.md

@@ -270,6 +270,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Fixed a negative number of periods returned by the _FIRE_ calculator when the goal is already met with no interest rate
 - Fixed an issue with the localization of the country names
 - Fixed an issue in the data provider service where quotes could be missing for symbols that exist in multiple data sources by keying the quotes response by the asset profile identifier
 

libs/ui/src/lib/fire-calculator/fire-calculator.service.spec.ts

@@ -32,6 +32,38 @@ describe('FireCalculatorService', () => {
       expect(periodsToRetire).toBe(9);
     });
 
+    it('should return 0 with no interest rate when the goal is already met', async () => {
+      const r = 0;
+      const P = 2000;
+      const totalAmount = 1900;
+      const PMT = 100;
+
+      const periodsToRetire = fireCalculatorService.calculatePeriodsToRetire({
+        P,
+        r,
+        PMT,
+        totalAmount
+      });
+
+      expect(periodsToRetire).toBe(0);
+    });
+
+    it('should return the correct positive amount of periods to retire with no interest rate', async () => {
+      const r = 0;
+      const P = 1000;
+      const totalAmount = 5000;
+      const PMT = 250;
+
+      const periodsToRetire = fireCalculatorService.calculatePeriodsToRetire({
+        P,
+        r,
+        PMT,
+        totalAmount
+      });
+
+      expect(periodsToRetire).toBe(16);
+    });
+
     it('should return the 0 when total amount is 0', async () => {
       const r = 0.05;
       const P = 100000;

libs/ui/src/lib/fire-calculator/fire-calculator.service.ts

@@ -52,7 +52,7 @@ export class FireCalculatorService {
   }) {
     if (r === 0) {
       // No compound interest
-      return (totalAmount - P) / PMT;
+      return Math.max(0, (totalAmount - P) / PMT);
     } else if (totalAmount <= P) {
       return 0;
     }