Make new constructions with years between 0-100 make dates in 1900s

This is consistent with how the builtin Date object works
Fix padding in ISO strings to be consistent with Date objects

lib/index.d.ts

@@ -1,110 +1,110 @@
 export default DateOnly;
 /** A date object with without time */
 export class DateOnly {
-    /**
-     * Crete a DateOnly Object from a number, numbers represent the days since
-     * 1 Jan 1970
-     * @param {number} n The number to be converted to a DateOnly Object
-     */
-    static fromNumber(n: number): DateOnly;
-    /**
-     * Create a DateOnly Object from some string. Wraps new Date(str)
-     * @param {string} s The string to read the date info from
-     */
-    static fromString(s: string): DateOnly;
-    /**
-     * Create a DateOnly Object from some string. Wraps new Date(str)
-     * @param {Date} d The date to use in creating a new DateOnly object
-     * using the date's UTC values
-     */
-    static fromDate(d: Date): DateOnly;
-    /**
-     * Create a new DateOnly object for the current date
-     * @returns {DateOnly} A donly only object with the current local date
-     */
-    static now(): DateOnly;
-    /**
-     * @private
-     * Check if an input returns a valid date object
-     * @param {*} val some input to be passed to new Date and checked for validity
-     */
-    private static "__#1@#isDate";
-    /**
-     * @private
-     * Create an invaid DateOnly object
-     * @returns {DateOnly} A date only object with it's invalid property set true
-     */
-    private static "__#1@#createInvalidDate";
-    /**
-     * @constructor
-     * Create a new DateOnly object
-     * @param {number} [year=1970] The year the of the date
-     * @param {number} [date=1] The year the of the date
-     * @param {number} [month=1] The year the of the date
-     */
-    constructor(year?: number, month?: number, date?: number);
-    /**
-     * Return the year only from the DateOnly
-     * @returns {number}
-     */
-    getFullYear(): number;
-    /**
-     * Return the month value from the DateOnly.
-     * Indexed from 1, 12 is december
-     * @returns {number}
-     */
-    getMonth(): number;
-    /**
-     * Return the date value, or the day of the month
-     * Indexed from 1, max of 31 depending the month
-     * @returns {number}
-     */
-    getDate(): number;
-    /**
-     * Return the year only from the DateOnly
-     * @param {number} v The new desired value for the year
-     */
-    setFullYear(v: number): void;
-    /**
-     * Get day of the week
-     */
-    getDay(): number;
-    /**
-     * Return the month value from the DateOnly.
-     * Indexed from 1, 12 is december
-     * @param {number} v The new desired value for the value
-     */
-    setMonth(v: number): void;
-    /**
-     * Set the date value, or the day of the month
-     * @param {number} v The new desired value for the date
-     */
-    setDate(v: number): void;
-    /**
-     * Set the date value, or the day of the month
-     * @param {string} [sep=-] The seperator to use between date components
-     * @returns {string} the date represented as a string
-     */
-    toString(sep?: string): string;
-    /**
-     * Return a string in ISO8601 format
-     * All time values are set to zero
-     * @returns {string} the date represented as an ISO8601 string
-     */
-    toISOString(): string;
-    /**
-     * JSON serializes the date to an ISO8601 date
-     * @returns {string} the date represented as an ISO8601 string
-     */
-    toJSON(): string;
-    /**
-     * Returns a Date stirng
-     */
-    toDateString(): string;
-    /**
-     * Returns if the current date time object is valid or not
-     */
-    isValid(): boolean;
-    #private;
+	/**
+	 * Crete a DateOnly Object from a number, numbers represent the days since
+	 * 1 Jan 1970
+	 * @param {number} n The number to be converted to a DateOnly Object
+	 */
+	static fromNumber(n: number): DateOnly;
+	/**
+	 * Create a DateOnly Object from some string. Wraps new Date(str)
+	 * @param {string} s The string to read the date info from
+	 */
+	static fromString(s: string): DateOnly;
+	/**
+	 * Create a DateOnly Object from some string. Wraps new Date(str)
+	 * @param {Date} d The date to use in creating a new DateOnly object
+	 * using the date's UTC values
+	 */
+	static fromDate(d: Date): DateOnly;
+	/**
+	 * Create a new DateOnly object for the current date
+	 * @returns {DateOnly} A donly only object with the current local date
+	 */
+	static now(): DateOnly;
+	/**
+	 * @private
+	 * Check if an input returns a valid date object
+	 * @param {*} val some input to be passed to new Date and checked for validity
+	 */
+	private static "__#1@#isDate";
+	/**
+	 * @private
+	 * Create an invaid DateOnly object
+	 * @returns {DateOnly} A date only object with it's invalid property set true
+	 */
+	private static "__#1@#createInvalidDate";
+	/**
+	 * @constructor
+	 * Create a new DateOnly object
+	 * @param {number} [year=1970] The year the of the date
+	 * @param {number} [date=1] The year the of the date
+	 * @param {number} [month=1] The year the of the date
+	 */
+	constructor(year?: number, month?: number, date?: number);
+	/**
+	 * Return the year only from the DateOnly
+	 * @returns {number}
+	 */
+	getFullYear(): number;
+	/**
+	 * Return the month value from the DateOnly.
+	 * Indexed from 1, 12 is december
+	 * @returns {number}
+	 */
+	getMonth(): number;
+	/**
+	 * Return the date value, or the day of the month
+	 * Indexed from 1, max of 31 depending the month
+	 * @returns {number}
+	 */
+	getDate(): number;
+	/**
+	 * Return the year only from the DateOnly
+	 * @param {number} v The new desired value for the year
+	 */
+	setFullYear(v: number): void;
+	/**
+	 * Get day of the week
+	 */
+	getDay(): number;
+	/**
+	 * Return the month value from the DateOnly.
+	 * Indexed from 1, 12 is december
+	 * @param {number} v The new desired value for the value
+	 */
+	setMonth(v: number): void;
+	/**
+	 * Set the date value, or the day of the month
+	 * @param {number} v The new desired value for the date
+	 */
+	setDate(v: number): void;
+	/**
+	 * Set the date value, or the day of the month
+	 * @param {string} [sep=-] The seperator to use between date components
+	 * @returns {string} the date represented as a string
+	 */
+	toString(sep?: string): string;
+	/**
+	 * Return a string in ISO8601 format
+	 * All time values are set to zero
+	 * @returns {string} the date represented as an ISO8601 string
+	 */
+	toISOString(): string;
+	/**
+	 * JSON serializes the date to an ISO8601 date
+	 * @returns {string} the date represented as an ISO8601 string
+	 */
+	toJSON(): string;
+	/**
+	 * Returns a Date stirng
+	 */
+	toDateString(): string;
+	/**
+	 * Returns if the current date time object is valid or not
+	 */
+	isValid(): boolean;
+	#private;
 }
-//# sourceMappingURL=index.d.ts.map
+//# sourceMappingURL=index.d.ts.map

lib/index.js

@@ -32,7 +32,11 @@ class DateOnly {
 	 * @param {number} [month=1] The year the of the date
 	 */
 	constructor(year = 1970, month = 1, date = 1) {
-		this.#year = +year;
+		let y = +year;
+		if (0 <= y && y < 100) {
+			y += 1900;
+		}
+		this.#year = y;
 		this.setMonth(+month);
 		this.#date = +date;
 	}
@@ -198,7 +202,7 @@ class DateOnly {
 			return "Invalid DateOnly";
 		}
 
-		return `${this.#year}${sep}${this.#month}${sep}${this.#date}`;
+		return `${this.#year}${sep}${this.#pad(this.#month)}${sep}${this.#pad(this.#date)}`;
 	}
 
 	/**
@@ -210,7 +214,17 @@ class DateOnly {
 		if (this.#invalid) {
 			return "Invalid DateOnly";
 		}
-		return `${this.#year}${sep}${this.#month}${sep}${this.#date}T:00:00:00.000Z`;
+
+		let prefix = "";
+		let padDigits = 4;
+		let y = this.#year;
+		if (y < 0) {
+			prefix = "-";
+			padDigits = 6;
+			y *= -1;
+		}
+
+		return `${prefix}${this.#pad(y, padDigits)}-${this.#pad(this.#month)}-${this.#pad(this.#date)}T00:00:00.000Z`;
 	}
 
 	/**
@@ -238,15 +252,15 @@ class DateOnly {
 		return !this.#invalid;
 	}
 
-    /**
-     * zero pad a number
-     * @param {number} n The number to pad
-     * @param {number} [d=2] The number of digits to pad
-     * @returns {string} the number zero padded
-     */
-    #pad(n, d=2) {
-        return String(n).padStart(d, '0');
-    }
+	/**
+	 * zero pad a number
+	 * @param {number} n The number to pad
+	 * @param {number} [d=2] The number of digits to pad
+	 * @returns {string} the number zero padded
+	 */
+	#pad(n, d = 2) {
+		return String(n).padStart(d, "0");
+	}
 }
 
 export { DateOnly };

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@patient-otter/dateonly",
-  "version": "0.1.4",
+  "version": "0.1.5",
   "description": "Date objects without time",
   "main": "lib/index.js",
   "scripts": {

test/create.test.js

@@ -21,9 +21,17 @@ describe("Creating DateOnly Objects", () => {
 
 	test("Create with random [in bounds] inputs", () => {
 		for (let k = 0; k < loops; k++) {
-			const y = Math.ceil(Math.random() * 4000);
+			let y = Math.ceil(Math.random() * 4000);
+			if (Math.random() < 0.2) {
+				y *= -1;
+			}
+
+			let shouldBe = y;
+			if (0 <= y && y < 100) {
+				shouldBe += 1900;
+			}
 			const d = new DateOnly(y);
-			expect(d.getFullYear()).toBe(y);
+			expect(d.getFullYear()).toBe(shouldBe);
 			expect(d.getMonth()).toBe(1);
 			expect(d.getDate()).toBe(1);
 		}
@@ -36,7 +44,12 @@ describe("Creating DateOnly Objects", () => {
 			const d = Math.ceil(Math.random() * 28);
 			const date = new DateOnly(`${y}`, `${m}`, `${d}`);
 
-			expect(date.getFullYear()).toBe(y);
+			let shouldBe = y;
+			if (0 <= y && y < 100) {
+				shouldBe += 1900;
+			}
+
+			expect(date.getFullYear()).toBe(shouldBe);
 			expect(date.getMonth()).toBe(m);
 			expect(date.getDate()).toBe(d);
 		}

test/string.test.js

@@ -0,0 +1,48 @@
+import { describe, expect, test } from "bun:test";
+import { DateOnly } from "../lib";
+
+describe("Creating strings from date only options", () => {
+	const testCases = [
+		{ year: 2044, month: 3, date: 9, expected: "2044-03-09" },
+		{ year: 2044, month: 10, date: 9, expected: "2044-10-09" },
+		{ year: 2044, month: 3, date: 19, expected: "2044-03-19" },
+		{ year: 2044, month: 11, date: 22, expected: "2044-11-22" },
+		{ year: 44, month: 11, date: 22, expected: "1944-11-22" },
+	];
+
+	for (const tc of testCases) {
+		test(`ToString: ${tc.expected}`, () => {
+			const d = new DateOnly(tc.year, tc.month, tc.date);
+			expect(d.toString()).toBe(tc.expected);
+		});
+	}
+
+	for (const tc of testCases) {
+		test(`ISO String: ${tc.expected}`, () => {
+			const d = new DateOnly(tc.year, tc.month, tc.date);
+			expect(d.toISOString()).toBe(`${tc.expected}T00:00:00.000Z`);
+		});
+	}
+
+	test("ISO String: bad DateOnly", () => {
+		const d = DateOnly.fromString("THIS WILL MAKE AN INVALID DateOnly kj;a!!!");
+		expect(d.toISOString()).toBe("Invalid DateOnly");
+	});
+
+	test("Date Strings", () => {
+		const loops = 200;
+		for (let k = 0; k < loops; k++) {
+			let y = Math.ceil(Math.random() * 4000);
+			const m = Math.ceil(Math.random() * 12);
+			const day = Math.ceil(Math.random() * 28);
+
+			if (Math.random() < 0.2) {
+				y *= -1;
+			}
+
+			const dt = new Date(Date.UTC(y, m - 1, day, 0, 0, 0));
+			const d = new DateOnly(y, m, day);
+			expect(d.toISOString()).toBe(dt.toISOString());
+		}
+	});
+});