fix: make numberFormat always return a string

Author: grunch

tests/util/index.spec.ts

@@ -42,29 +42,38 @@ describe('Utility Functions', () => {
   });
 
   describe('numberFormat', () => {
-    it('should return false for invalid currency code', () => {
+    it('returns the plain number as string for an invalid currency code', () => {
       const result = numberFormat('INVALID', 100);
-      expect(result).to.equal(false);
+      expect(result).to.equal('100');
     });
 
-    it('should return original number if no locale found', () => {
+    it('formats the number using the currency locale', () => {
       const result = numberFormat('USD', 1234.56);
-      expect(result).to.not.be.false;
+      expect(result).to.equal('1,234.56');
     });
 
-    it('should return original number for NaN input', () => {
+    it('returns a string for NaN input', () => {
       const result = numberFormat('USD', NaN);
-      expect(result).to.be.NaN;
+      expect(result).to.equal('NaN');
     });
 
-    it('should handle zero correctly', () => {
+    it('handles zero correctly', () => {
       const result = numberFormat('USD', 0);
-      expect(result).to.not.be.false;
+      expect(result).to.equal('0');
     });
 
-    it('should handle negative numbers', () => {
+    it('handles negative numbers', () => {
       const result = numberFormat('USD', -100);
-      expect(result).to.not.be.false;
+      expect(result).to.equal('-100');
+    });
+
+    it('always returns a string', () => {
+      const results = [
+        numberFormat('INVALID', 100),
+        numberFormat('USD', 1000),
+        numberFormat('USD', NaN),
+      ];
+      results.forEach(result => expect(result).to.be.a('string'));
     });
   });
 

util/index.ts

@@ -63,18 +63,17 @@ const plural = (n: number): string => {
 exports.plural = plural;
 
 // This function formats a number to locale strings.
-// If Iso code or locale code doesn´t exist, the function will return a number without format.
-const numberFormat = (code: string, number: number) => {
-  if (!isIso4217(code)) return false;
+// If Iso code or locale code doesn´t exist, the function will return the number as a plain string.
+const numberFormat = (code: string, number: number): string => {
+  if (!isIso4217(code)) return String(number);
 
-  if (!currencies[code]) return number;
+  if (!currencies[code]) return String(number);
 
   const locale = currencies[code].locale;
-  const numberToLocaleString = Intl.NumberFormat(locale);
 
-  if (!locale || isNaN(number)) return number;
+  if (!locale || isNaN(number)) return String(number);
 
-  return numberToLocaleString.format(number);
+  return Intl.NumberFormat(locale).format(number);
 };
 
 // This function checks if the current buyer and seller were doing circular operations