Complete UTCDate implementation

index.ts

@@ -44,18 +44,57 @@ export class UTCDate extends Date {
  }
  }
 
+ getTimezoneOffset() {
+ return 0;
+ }
+
  toString(): string {
+ const date = this.toDateString();
+ const time = this.toTimeString();
+ return `${date} ${time}`;
+ }
+
+ toDateString(): string {
  const weekday = weekdayFormat.format(this);
  const date = dateFormat.format(this);
  const year = this.getFullYear();
- const time = this.toTimeString();
- return `${weekday} ${date} ${year} ${time}`;
+ return `${weekday} ${date} ${year}`;
  }
 
  toTimeString(): string {
  const time = timeFormat.format(this);
  return `${time} GMT+0000 (Coordinated Universal Time)`;
  }
+
+ toLocaleString(
+ locales?: string | string[],
+ options?: Intl.DateTimeFormatOptions
+ ): string {
+ return Date.prototype.toLocaleString.call(this, locales, {
+ timeZone: "UTC",
+ ...options,
+ });
+ }
+
+ toLocaleDateString(
+ locales?: string | string[],
+ options?: Intl.DateTimeFormatOptions
+ ): string {
+ return Date.prototype.toLocaleDateString.call(this, locales, {
+ timeZone: "UTC",
+ ...options,
+ });
+ }
+
+ toLocaleTimeString(
+ locales?: string | string[],
+ options?: Intl.DateTimeFormatOptions
+ ): string {
+ return Date.prototype.toLocaleTimeString.call(this, locales, {
+ timeZone: "UTC",
+ ...options,
+ });
+ }
 }
 
 var getMethods: Array<keyof Date> = [

test.ts

@@ -62,6 +62,12 @@ describe("UTCDate", () => {
  it.todo("returns UTC seconds");
  });
 
+ describe("getTimezoneOffset", () => {
+ it("returns 0", () => {
+ expect(new UTCDate(1999, 11, 31, 23).getTimezoneOffset()).toBe(0);
+ });
+ });
+
  describe("setDate", () => {
  it("sets UTC date", () => {
  const date = new UTCDate(1987, 1, 11, 23);
@@ -116,6 +122,24 @@ describe("UTCDate", () => {
  "Wed Feb 11 1987 12:13:14 GMT+0000 (Coordinated Universal Time)"
  );
  });
+
+ it("works with Symbol.toPrimitive", () => {
+ expect(
+ new UTCDate(1987, 1, 11, 12, 13, 14, 15)[Symbol.toPrimitive]("string")
+ ).toBe("Wed Feb 11 1987 12:13:14 GMT+0000 (Coordinated Universal Time)");
+
+ expect(
+ new UTCDate(1987, 1, 11, 12, 13, 14, 15)[Symbol.toPrimitive]("default")
+ ).toBe("Wed Feb 11 1987 12:13:14 GMT+0000 (Coordinated Universal Time)");
+ });
+ });
+
+ describe("toDateString", () => {
+ it("returns string representing the given date in UTC timezone", () => {
+ expect(new UTCDate(1987, 1, 11, 12, 13, 14, 15).toDateString()).toBe(
+ "Wed Feb 11 1987"
+ );
+ });
  });
 
  describe("toTimeString", () => {
@@ -125,4 +149,76 @@ describe("UTCDate", () => {
  );
  });
  });
+
+ describe("toLocaleString", () => {
+ it("returns localized date time string", () => {
+ expect(
+ new UTCDate(1987, 1, 11, 12, 13, 14, 15).toLocaleString("en-GB")
+ ).toBe("11/02/1987, 12:13:14");
+ });
+
+ it("allows to pass options", () => {
+ expect(
+ new UTCDate(1987, 1, 11, 12, 13, 14, 15).toLocaleString("en-GB", {
+ month: "long",
+ })
+ ).toBe("February");
+ });
+
+ it("allows to override the timezone", () => {
+ expect(
+ new UTCDate(1987, 1, 11, 12, 13, 14, 15).toLocaleString("en-GB", {
+ timeZone: "Asia/Kolkata",
+ })
+ ).toBe("11/02/1987, 17:43:14");
+ });
+ });
+
+ describe("toLocaleDateString", () => {
+ it("returns localized date string", () => {
+ expect(
+ new UTCDate(1999, 11, 31, 23, 59, 59).toLocaleDateString("en-GB")
+ ).toBe("31/12/1999");
+ });
+
+ it("allows to pass options", () => {
+ expect(
+ new UTCDate(1999, 11, 31, 23, 59, 59).toLocaleString("en-GB", {
+ month: "long",
+ })
+ ).toBe("December");
+ });
+
+ it("allows to override the timezone", () => {
+ expect(
+ new UTCDate(1999, 11, 31, 23, 59, 59).toLocaleDateString("en-GB", {
+ timeZone: "Asia/Kolkata",
+ })
+ ).toBe("01/01/2000");
+ });
+ });
+
+ describe("toLocaleTimeString", () => {
+ it("returns localized time string", () => {
+ expect(
+ new UTCDate(1987, 1, 11, 12, 13, 14, 15).toLocaleTimeString("en-GB")
+ ).toBe("12:13:14");
+ });
+
+ it("allows to pass options", () => {
+ expect(
+ new UTCDate(1987, 1, 11, 12, 13, 14, 15).toLocaleTimeString("en-GB", {
+ hour: "numeric",
+ })
+ ).toBe("12");
+ });
+
+ it("allows to override the timezone", () => {
+ expect(
+ new UTCDate(1987, 1, 11, 12, 13, 14, 15).toLocaleTimeString("en-GB", {
+ timeZone: "Asia/Kolkata",
+ })
+ ).toBe("17:43:14");
+ });
+ });
 });