[WIP] Implement formatCurrencyWithNames

src/index.d.ts

@@ -17,3 +17,10 @@ export function formatCurrency(
   locale: string,
   raw: boolean
 ): string;
+
+// format currency with names
+export function formatCurrencyWithNames(
+  amount: number,
+  isoCode: string,
+  locale: string
+): string;

src/index.js

@@ -319,3 +319,37 @@ export function formatCurrency(amount, isoCode, locale = "en", raw = false) {
     }
   }
 }
+
+export function formatCurrencyWithNames(amount, isoCode, locale = "en") {
+  isoCode = isoCode.toUpperCase();
+  if (currentISOCode !== isoCode || currentLocale != locale) {
+    currentISOCode = isoCode;
+    currentLocale = locale;
+
+    // Formatters are tied to currency code, we try to initialize as infrequently as possible.
+    initializeFormatters(isoCode, locale);
+  }
+
+  const absPrice = Math.abs(Number(amount));
+  let price = 0;
+  let suffix = "";
+  if (absPrice >= 1.0e9) {
+    // If Billion
+    price = absPrice / 1.0e9;
+    suffix = "B";
+  } else if (abs >= 1.0e6) {
+    // If Million
+    price = absPrice / 1.0e6;
+    suffix = "M";
+  } else if (absPrice >= 1.0e3) {
+    // If Thousands
+    price = absPrice / 1.0e3;
+    suffix = "K";
+  }
+  if (isCrypto(isoCode)) {
+    price = Number(price.toFixed(3));
+    return `${price}${suffix} ${isoCode}`;
+  } else {
+    return formatCurrency(price, isoCode, locale, false) + suffix;
+  }
+}

src/test.js

@@ -1,4 +1,9 @@
-import { formatCurrency, isCrypto, clearCache } from "./index";
+import {
+  formatCurrency,
+  isCrypto,
+  clearCache,
+  formatCurrencyWithNames
+} from "./index";
 
 test("isCrypto", () => {
   expect(isCrypto("BTC")).toBe(true);
@@ -148,3 +153,24 @@ describe("Intl.NumberFormat not supported", () => {
     });
   });
 });
+
+describe("large number", () => {
+  describe("Billion", () => {
+    const billionVal1 = 9.101222e9;
+    const billionResVal1 = "9.101B";
+    const billionVal2 = 9e9;
+    const billionResVal2 = "9B";
+
+    test("format USD", () => {
+      expect(formatCurrencyWithNames(billionVal1, "USD", "en")).toEqual(
+        "USD " + billionResVal1
+      );
+    });
+
+    test("format BTC", () => {
+      expect(formatCurrencyWithNames(billionVal2, "BTC", "en")).toEqual(
+        billionResVal2 + " BTC"
+      );
+    });
+  });
+});