new feature: currency XCG

- historical date adjustment

CHANGELOG.md

@@ -13,7 +13,7 @@ Strictly follows [Semantic Versioning 2.0.0.](https://semver.org/)
     currencyName: "Netherlands Antillean Guilder",
     numericCode: 532,
     minorUnit: 2,
-    historicalFrom: "2025-07-01" // CHANGED (before: undefined)
+    historicalFrom: "2025-03-31" // CHANGED (before: undefined)
   },
   // ... other currencies
   {

__tests__/getIso4217Currencies.test.ts

@@ -28,16 +28,16 @@ describe('getIso4217Currencies', () => {
     expect(countries.find(x => x.alpha3Code === "HRK")).toBeDefined();
   });
 
-  test('Caribbean Guilder (XCG) and Netherlands Antillean Guilder (ANG) currencies are returned', () => {
-    const countries = getIso4217Currencies("2025-03-31");
-    expect(countries).toHaveLength(181);
-    expect(countries.find(x => x.alpha3Code === "XCG")).toBeDefined();
+  test('Netherlands Antillean Guilder (ANG) currency is returned', () => {
+    const countries = getIso4217Currencies("2024-01-01");
+    expect(countries).toHaveLength(180);
     expect(countries.find(x => x.alpha3Code === "ANG")).toBeDefined();
   });
 
-  test('Netherlands Antillean Guilder (ANG) currency is no longer returned', () => {
-    const countries = getIso4217Currencies("2025-07-01");
+  test('Caribbean Guilder (XCG) is returned', () => {
+    const countries = getIso4217Currencies("2025-03-31");
     expect(countries).toHaveLength(180);
+    expect(countries.find(x => x.alpha3Code === "XCG")).toBeDefined();
     expect(countries.find(x => x.alpha3Code === "ANG")).toBeUndefined();
   });
 

src/findIso4217Currency.ts

@@ -3,22 +3,18 @@ import { Iso4217Alpha3Code, Iso4217Currency, Iso4217NumericCode } from "./types/
 
 export function findIso4217Currency(code: Iso4217Alpha3Code | Iso4217NumericCode): Iso4217Currency | undefined {
   if (code === 532) {
-    // HINT: edge case with duplicated numeric code (for some period both are active currencies)
     const xcgCurrency = iso4217Currencies.find(x => x.alpha3Code === "XCG")!;
-    const angCurrency = iso4217Currencies.find(x => x.alpha3Code === "ANG")!;
     const now = new Date();
 
     if (now >= new Date(xcgCurrency.introducedIn!)) {
-      if (new Date(angCurrency.historicalFrom!) <= now) {
-        console?.warn?.("In the current period there are two active currencies with the same currency numerical code."
-          + " The new XCG currency is returned for this period, which will ultimately replace ANG."
-          + " To make sure you select the intended currency please use alpha 3 code.");
-      }
+      console?.warn?.("There are two currencies with the same currency numerical code (XCG, ANG)."
+        + " The new XCG currency is returned which ultimately replaces ANG."
+        + " To make sure you select the intended currency please use alpha 3 code.");
 
       return xcgCurrency;
     }
 
-    return angCurrency;
+    return iso4217Currencies.find(x => x.alpha3Code === "ANG");
   }
 
   const predicate: (value: Iso4217Currency) => boolean =

src/internal/iso3166CountryToIso4217Currency.ts

@@ -2,7 +2,7 @@ import { Iso3166Alpha3Code } from "../types/iso3166";
 import { Iso4217Alpha3Code } from "../types/iso4217";
 
 /** @internal */
-export type Iso4217Alpha3CodeResolver = Iso4217Alpha3Code |undefined | ((d: Date) => Iso4217Alpha3Code);
+export type Iso4217Alpha3CodeResolver = Iso4217Alpha3Code | undefined | ((d: Date) => Iso4217Alpha3Code);
 
 /** @internal */
 export const iso3166CountryToIso4217Currency = new Map<Iso3166Alpha3Code, Iso4217Alpha3CodeResolver>([

src/internal/iso4217Currencies.ts

@@ -31,7 +31,7 @@ export const iso4217Currencies: Iso4217Currency[] = [
     currencyName: "Netherlands Antillean Guilder",
     numericCode: 532,
     minorUnit: 2,
-    historicalFrom: "2025-07-01"
+    historicalFrom: "2025-03-31"
   },
   {
     alpha3Code: "AOA",