fix: currency symbol placement evaluation [ATLAS-199] (#146)

* [fix]: fix logic for prefix evaluation of currency symbol

* [test]: add missing UTs

* Create slimy-rules-thank.md

* [test]: add missing UTs

.changeset/slimy-rules-thank.md

@@ -0,0 +1,5 @@
+---
+"@razorpay/i18nify-js": patch
+---
+
+currency symbol placement evaluation in formatNumberToParts

packages/i18nify-js/src/modules/currency/__tests__/formatNumberByParts.test.ts

@@ -237,4 +237,30 @@ describe('formatNumberByParts', () => {
       ),
     );
   });
+
+  it('should return correct value for isPrefixSymbol for negative amounts', () => {
+    const inrParts = formatNumberByParts(-1234567, {
+      currency: 'INR',
+      locale: 'en-IN',
+      intlOptions: { style: 'currency' },
+    } as any);
+
+    const eurParts = formatNumberByParts(-1234567, {
+      currency: 'EUR',
+      locale: 'de-DE',
+      intlOptions: { style: 'currency' },
+    } as any);
+
+    expect(inrParts.isPrefixSymbol).toEqual(true);
+    expect(eurParts.isPrefixSymbol).toEqual(false);
+
+    expect(inrParts.minusSign).toEqual('-');
+    expect(eurParts.minusSign).toEqual('-');
+  });
+
+  it('should return true as default value of isPrefixSymbol even when currency code is not passed', () => {
+    expect(formatNumberByParts(-1234567, {} as any).isPrefixSymbol).toEqual(
+      true,
+    );
+  });
 });

packages/i18nify-js/src/modules/currency/formatNumberByParts.ts

@@ -43,7 +43,9 @@ const formatNumberByParts = (
 
     return {
       ...formattedObj,
-      isPrefixSymbol: parts[0].type === 'currency',
+      isPrefixSymbol:
+        parts.findIndex((item) => item.type === 'currency') <
+        parts.findIndex((item) => item.type === 'integer'),
       rawParts: parts,
     };
   } catch (err) {