refactor: split currency and key/metal formatting into separate units

this simplifies functions and tests, and will make currency optional/variable later

__tests__/currency.test.ts

@@ -0,0 +1,17 @@
+import { describe, expect, test, jest, mock, beforeEach } from "bun:test";
+import { convertTF2PriceToUSD } from '../src/content/utils/currency'
+
+mock.module('../src/content/config', () => ({
+  conversion_ref_usd: 0.05 // Mock conversion rate
+}))
+
+
+describe('Currency Service', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  });
+
+  test('convertTF2PriceToUSD returns correct price', () => {
+    expect(convertTF2PriceToUSD(1, 10, 50)).toBe(3);
+  })
+})

__tests__/formatting.test.ts

@@ -16,34 +16,34 @@ describe('formatPrice', () => {
     });
 
     test('formats price with keys and metal', () => {
-        expect(formatPrice(2, 10, 50)).toBe('2.2 keys (US$5.50)');
+        expect(formatPrice(2, 10, 50)).toBe('2.2 keys');
         expect($T).toHaveBeenCalledWith('%@ keys');
     });
 
     test('formats price with metal only', () => {
-        expect(formatPrice(0, 15.75, 50)).toBe('15.75 ref (US$0.79)');
+        expect(formatPrice(0, 15.75, 50)).toBe('15.75 ref');
     });
 
     test('formats price with metal only and whole number', () => {
-        expect(formatPrice(0, 3, 50)).toBe('3 ref (US$0.16)');
+        expect(formatPrice(0, 3, 50)).toBe('3 ref');
     });
 
     test('uses singular key form', () => {
-        expect(formatPrice(1, 0, 50)).toBe('1 key (US$2.50)');
+        expect(formatPrice(1, 0, 50)).toBe('1 key');
         expect($T).toHaveBeenCalledWith('%@ key');
     });
 
     test('rounds USD up to nearest cent', () => {
-        expect(formatPrice(3, 7.33, 35)).toBe('3.21 keys (US$5.62)');  // (3 * 35 + 7.33) * 0.05 = 5.6165 → 5.62
+        expect(formatPrice(3, 7.33, 35)).toBe('3.21 keys');  // (3 * 35 + 7.33) * 0.05 = 5.6165 → 5.62
     });
 
     test('handles different locale formatting', () => {
-        expect(formatPrice(2, 10, 50, 'de')).toMatch(/2,2 keys \(US\$5,50\)/);
-        expect(formatPrice(0, 15.75, 50, 'de')).toMatch(/15,75 ref \(US\$0,79\)/);
+        expect(formatPrice(2, 10, 50, 'de')).toMatch(/2,2 keys/);
+        expect(formatPrice(0, 15.75, 50, 'de')).toMatch(/15,75 ref/);
     });
 
     test('handles zero values', () => {
-        expect(formatPrice(0, 0, 50)).toBe('0 ref (US$0.00)');
-        expect(formatPrice(0, 0, 50, 'de')).toMatch(/0 ref \(US\$0,00\)/);
+        expect(formatPrice(0, 0, 50)).toBe('0 ref');
+        expect(formatPrice(0, 0, 50, 'de')).toMatch(/0 ref/);
     });
 });

src/content/uiRenderer.ts

@@ -1,4 +1,5 @@
 import { ItemPriceData } from "./priceService";
+import { convertTF2PriceToUSD } from "./utils/currency";
 import { formatPrice } from "./utils/formatting";
 import { $T } from "./utils/localization";
 
@@ -19,8 +20,22 @@ export function createPriceRow(qualityName: string, data: ItemPriceData, keyPric
 
   const priceData = document.createElement("td");
   const priceLink = document.createElement("span");
-  const priceString = data ? formatPrice(data.keys, data.metal, keyPrice.metal, locale).trim() : $T('Data unavailable')
-  priceLink.innerHTML = priceString // + `<br>$${data.scmPrice}`
+  var priceString: string = ''
+
+  if(data) {
+    const currencyFormatter = new Intl.NumberFormat(locale, {
+      minimumFractionDigits: 2,
+      maximumFractionDigits: 2,
+     });
+
+    priceString += [
+      formatPrice(data.keys, data.metal, keyPrice.metal, locale).trim(),
+      '(US$' + currencyFormatter.format(convertTF2PriceToUSD(data.keys, data.metal, keyPrice.metal)) + ')'
+    ].join(' ').trim()
+  } else {
+    priceString += $T('Data unavailable')
+  }
+  priceLink.innerHTML = priceString
   priceData.appendChild(priceLink);
   priceRow.appendChild(priceData);
   return priceRow;

src/content/utils/currency.ts

@@ -0,0 +1,8 @@
+import { conversion_ref_usd } from '../config';
+
+export function convertTF2PriceToUSD(keys: number, metal: number, keyPrice: number): number {
+	const pureMetal = (keys * keyPrice) + metal;
+
+	// Round price up to nearest cent
+  return Math.ceil(pureMetal * conversion_ref_usd * 100) / 100
+}

src/content/utils/formatting.ts

@@ -7,7 +7,6 @@ function toFixed(num: number, fixed: number) {
 }
 
 export function formatPrice(keys: number, metal: number, keyPrice: number, locale: string = 'en') {
-	const pureMetal = (keys * keyPrice) + metal;
 	const formattedKeys = +(keys + (metal / keyPrice)).toFixed(2)
 
 	var output: string = ''
@@ -16,13 +15,6 @@ export function formatPrice(keys: number, metal: number, keyPrice: number, local
 	} else {
 		output += $T("%@ ref").replace('%@', (+toFixed(metal, 2)).toLocaleString(locale))
 	}
-	const currencyFormatter = new Intl.NumberFormat(locale, {
-		minimumFractionDigits: 2,
-		maximumFractionDigits: 2,
- 	});
 
-	// Round price up to nearest cent
- 	const price = Math.ceil(pureMetal * conversion_ref_usd * 100) / 100
-	output += ` (US$${currencyFormatter.format(price)})`
 	return output;
 }