feat: ethiopic date lib

src/ethiopic/lib/addMonths.test.ts

@@ -1 +1,3 @@
-test.todo("addMonths should correctly add months to an Ethiopic date");
+test.todo("should add positive months correctly in Ethiopic calendar");
+test.todo("should add negative months correctly in Ethiopic calendar");
+test.todo("should handle month overflow correctly in Ethiopic calendar");

src/ethiopic/lib/addMonths.ts

@@ -1,3 +1,4 @@
+import { daysInMonth } from "../utils/daysInMonth.js";
 import { toEthiopicDate, toGregorianDate } from "../utils/index.js";
 
 /**
@@ -9,8 +10,19 @@ import { toEthiopicDate, toGregorianDate } from "../utils/index.js";
  */
 export function addMonths(date: Date, amount: number): Date {
   const { year, month, day } = toEthiopicDate(date);
-  const totalMonths = month + amount - 1;
-  const newYear = year + Math.floor(totalMonths / 12);
-  const newMonth = (totalMonths % 12) + 1;
-  return toGregorianDate({ year: newYear, month: newMonth, day });
+  let newMonth = month + amount;
+  const yearAdjustment = Math.floor((newMonth - 1) / 13);
+  newMonth = ((newMonth - 1) % 13) + 1;
+
+  if (newMonth < 1) {
+    newMonth += 13;
+  }
+
+  const newYear = year + yearAdjustment;
+
+  // Adjust day if it exceeds the month length
+  const monthLength = daysInMonth(newMonth, newYear);
+  const newDay = Math.min(day, monthLength);
+
+  return toGregorianDate({ year: newYear, month: newMonth, day: newDay });
 }

src/ethiopic/lib/addYears.test.ts

@@ -1 +1,5 @@
-test.todo("addYears should correctly add years to an Ethiopic date");
+test.todo("should add positive years correctly in Ethiopic calendar");
+test.todo("should add negative years correctly in Ethiopic calendar");
+test.todo(
+  "should maintain month and day when adding years in Ethiopic calendar"
+);

src/ethiopic/lib/addYears.ts

@@ -1,20 +1,7 @@
-import {
-  toEthiopicDate,
-  isEthiopicLeapYear,
-  toGregorianDate
-} from "../utils/index.js";
+import { toEthiopicDate, toGregorianDate } from "../utils/index.js";
 
-/**
- * Adds years to an Ethiopic date
- *
- * @param {Date} date - The original date
- * @param {number} amount - The number of years to add
- * @returns {Date} The new date
- */
 export function addYears(date: Date, amount: number): Date {
   const { year, month, day } = toEthiopicDate(date);
   const newYear = year + amount;
-  const newDay =
-    month === 13 && day === 6 && !isEthiopicLeapYear(newYear) ? 5 : day;
-  return toGregorianDate({ year: newYear, month, day: newDay });
+  return toGregorianDate({ year: newYear, month, day });
 }

src/ethiopic/lib/differenceInCalendarMonths.test.ts

@@ -0,0 +1,5 @@
+test.todo(
+  "should calculate difference in months within the same Ethiopic year"
+);
+test.todo("should calculate difference in months across Ethiopic years");
+test.todo("should return zero for same Ethiopic date");

src/ethiopic/lib/differenceInCalendarMonths.ts

@@ -1,4 +1,4 @@
-import { toEthiopicDate, isEthiopicLeapYear } from "../utils/index.js";
+import { toEthiopicDate } from "../utils/index.js";
 
 /**
  * Difference in calendar months
@@ -13,13 +13,8 @@ export function differenceInCalendarMonths(
 ): number {
   const ethiopicLeft = toEthiopicDate(dateLeft);
   const ethiopicRight = toEthiopicDate(dateRight);
-  const leapDays = Array.from(
-    { length: ethiopicLeft.year - ethiopicRight.year },
-    (_, i) => ethiopicRight.year + i
-  ).filter(isEthiopicLeapYear).length;
   return (
-    (ethiopicLeft.year - ethiopicRight.year) * 12 +
-    (ethiopicLeft.month - ethiopicRight.month) +
-    leapDays
+    (ethiopicLeft.year - ethiopicRight.year) * 13 +
+    (ethiopicLeft.month - ethiopicRight.month)
   );
 }

src/ethiopic/lib/endOfMonth.test.ts

@@ -1 +1,4 @@
-test.todo("should return the correct end of the month date for a given date");
+test.todo("Should return the last day of a 30-day Ethiopic month");
+test.todo(
+  "Should handle Pagume (13th month) correctly in leap and non-leap years"
+);

src/ethiopic/lib/endOfMonth.ts

@@ -1,8 +1,5 @@
-import {
-  toEthiopicDate,
-  isEthiopicLeapYear,
-  toGregorianDate
-} from "../utils/index.js";
+import { daysInMonth } from "../utils/daysInMonth.js";
+import { toEthiopicDate, toGregorianDate } from "../utils/index.js";
 
 /**
  * End of month
@@ -12,6 +9,6 @@ import {
  */
 export function endOfMonth(date: Date): Date {
   const { year, month } = toEthiopicDate(date);
-  const daysInMonth = month === 13 ? (isEthiopicLeapYear(year) ? 6 : 5) : 30;
-  return toGregorianDate({ year, month, day: daysInMonth });
+  const day = daysInMonth(month, year);
+  return toGregorianDate({ year, month, day: day });
 }

src/ethiopic/lib/endOfYear.test.ts

@@ -1 +1,4 @@
-test.todo("should return the correct end of the year date for a given date");
+describe("endOfYear", () => {
+  test.todo("should return last day of Ethiopic year for non-leap year");
+  test.todo("should return last day of Ethiopic year for leap year");
+});

src/ethiopic/lib/format.test.ts

@@ -0,0 +1,6 @@
+describe("format", () => {
+  test.todo("should format date in Ethiopic calendar");
+  test.todo("should format Ethiopic month names correctly");
+  test.todo("should format time components correctly");
+  test.todo("should format full date with Ethiopic day names");
+});

src/ethiopic/lib/format.ts

@@ -0,0 +1,100 @@
+import { Locale } from "date-fns";
+
+import { toEthiopicDate } from "../utils/index.js";
+
+export interface FormatOptions {
+  locale?: Locale;
+  weekStartsOn?: 0 | 1 | 2 | 3 | 4 | 5 | 6;
+  firstWeekContainsDate?: 1 | 2 | 3 | 4 | 5 | 6 | 7;
+  useAdditionalWeekYearTokens?: boolean;
+  useAdditionalDayOfYearTokens?: boolean;
+}
+
+function getEtDayName(day: Date, short: boolean = true): string {
+  const dayOfWeek = day.getDay();
+  return short ? shortDays[dayOfWeek] : longDays[dayOfWeek];
+}
+
+function getEtMonthName(m: number): string {
+  if (m > 0 && m <= 13) {
+    return ethMonths[m - 1];
+  }
+  return "";
+}
+
+function formatEthiopianDate(
+  dateObj: Date | undefined,
+  formatStr: string
+): string {
+  const etDate = dateObj ? toEthiopicDate(dateObj) : undefined;
+
+  if (!etDate) return "";
+
+  switch (formatStr) {
+    case "LLLL yyyy":
+    case "LLLL y":
+      return `${getEtMonthName(etDate.month)} ${etDate.year}`;
+
+    case "LLLL":
+      return getEtMonthName(etDate.month);
+
+    case "yyyy-MM-dd":
+      return `${etDate.year}-${etDate.month
+        .toString()
+        .padStart(2, "0")}-${etDate.day.toString().padStart(2, "0")}`;
+
+    case "yyyy-MM":
+      return `${etDate.year}-${etDate.month.toString().padStart(2, "0")}`;
+
+    case "d":
+      return etDate.day.toString();
+    case "PPP":
+      return ` ${getEtMonthName(etDate.month)} ${etDate.day}, ${etDate.year}`;
+    case "PPPP":
+      if (!dateObj) return "";
+      return `${getEtDayName(dateObj)}, ${getEtMonthName(etDate.month)} ${
+        etDate.day
+      }, ${etDate.year}`;
+
+    case "cccc":
+      return dateObj ? getEtDayName(dateObj, false) : "";
+    case "cccccc":
+      return dateObj ? getEtDayName(dateObj) : "";
+
+    default:
+      return `${etDate.day}/${etDate.month}/${etDate.year}`;
+  }
+}
+
+export function format(
+  date: Date,
+  formatStr: string,
+  options?: FormatOptions
+): string {
+  // Handle time formats using original date-fns format
+  if (formatStr.includes("hh:mm") || formatStr.includes("a")) {
+    // Use regular date formatting for time components
+    return new Intl.DateTimeFormat("en-US", {
+      hour: "numeric",
+      minute: "numeric",
+      hour12: formatStr.includes("a")
+    }).format(date);
+  }
+
+  return formatEthiopianDate(date, formatStr);
+}export const ethMonths = [
+  "መስከረም",
+  "ጥቅምት",
+  "ህዳር",
+  "ታህሳስ",
+  "ጥር",
+  "የካቲት",
+  "መጋቢት",
+  "ሚያዚያ",
+  "ግንቦት",
+  "ሰኔ",
+  "ሐምሌ",
+  "ነሀሴ",
+  "ጳጉሜ"
+];export const shortDays = ["እ", "ሰ", "ማ", "ረ", "ሐ", "ዓ", "ቅ"];
+export const longDays = ["እሁድ", "ሰኞ", "ማክሰኞ", "ረቡዕ", "ሐሙስ", "ዓርብ", "ቅዳሜ"];

src/ethiopic/lib/formatNumber.test.ts

@@ -0,0 +1,5 @@
+describe("formatNumber", () => {
+  test.todo("should format numbers using Ethiopic numerals");
+  test.todo("should format numbers using latin numerals by default");
+  test.todo("should handle zero and negative numbers correctly");
+});

src/ethiopic/lib/formatNumber.ts

@@ -0,0 +1,8 @@
+export function formatNumber(value: number, numerals: string = "latn"): string {
+  // Use Intl.NumberFormat to create a formatter with the specified numbering system
+  const formatter = new Intl.NumberFormat("en-US", {
+    numberingSystem: numerals
+  });
+
+  return formatter.format(value);
+}

src/ethiopic/lib/getMonth.test.ts

@@ -1 +1,4 @@
-test.todo("should return the correct zero-based month index for a given date");
+describe("getMonth", () => {
+  test.todo("should return correct Ethiopic month (0-based)");
+  test.todo("should handle Pagume (13th month) correctly");
+});

src/ethiopic/lib/getWeek.test.ts

@@ -1 +1,6 @@
-test.todo("should return the correct week number for a given date");
+describe("getWeek", () => {
+  test.todo("should return correct Ethiopic week number");
+  test.todo("should handle different week start options");
+  test.todo("should handle dates at Ethiopic year boundaries");
+  test.todo("should maintain week continuity in Ethiopic calendar");
+});

src/ethiopic/lib/getWeek.ts

@@ -1,6 +1,6 @@
-import { toGregorianDate, toEthiopicDate } from "../utils/index.js";
+import type { GetWeekOptions } from "date-fns";
 
-import { differenceInCalendarDays } from "./differenceInCalendarDays.js";
+import { toGregorianDate, toEthiopicDate } from "../utils/index.js";
 
 /**
  * Get week
@@ -11,16 +11,59 @@ import { differenceInCalendarDays } from "./differenceInCalendarDays.js";
  *   week (0 - Sunday). Default is `0`
  * @returns {number} The week number
  */
-export function getWeek(
-  date: Date,
-  options?: { weekStartsOn?: number }
-): number {
-  const weekStartsOn = options?.weekStartsOn ?? 0; // Default to Sunday
-  const startOfYear = toGregorianDate({
-    year: toEthiopicDate(date).year,
+export function getWeek(date: Date, options?: GetWeekOptions): number {
+  const { year } = toEthiopicDate(date);
+
+  // Get the first day of the current year
+  const firstDayOfYear = toGregorianDate({
+    year: year,
+    month: 1,
+    day: 1
+  });
+
+  // Get the first day of next year
+  const firstDayOfNextYear = toGregorianDate({
+    year: year + 1,
     month: 1,
     day: 1
   });
-  const diffInDays = differenceInCalendarDays(date, startOfYear);
-  return Math.floor((diffInDays + weekStartsOn) / 7) + 1;
+
+  // Adjust to the start of the week (Monday)
+  const getWeekStart = (date: Date) => {
+    const daysSinceMonday = (date.getDay() + 6) % 7;
+    const weekStart = new Date(date);
+    weekStart.setDate(date.getDate() - daysSinceMonday);
+    return weekStart;
+  };
+
+  const firstWeekStart = getWeekStart(firstDayOfYear);
+  const nextYearFirstWeekStart = getWeekStart(firstDayOfNextYear);
+
+  // If the date is in the last week of the year, check if it belongs to week 1 of next year
+  if (date >= nextYearFirstWeekStart) {
+    return 1;
+  }
+
+  // Calculate days since the first week start
+  const daysSinceStart = Math.floor(
+    (date.getTime() - firstWeekStart.getTime()) / (24 * 60 * 60 * 1000)
+  );
+
+  // If the date is before the first week of its year, it belongs to the last week of previous year
+  if (date < firstWeekStart) {
+    const prevYearFirstDay = toGregorianDate({
+      year: year - 1,
+      month: 1,
+      day: 1
+    });
+    const prevYearFirstWeekStart = getWeekStart(prevYearFirstDay);
+    const daysSincePrevStart = Math.floor(
+      (date.getTime() - prevYearFirstWeekStart.getTime()) /
+        (24 * 60 * 60 * 1000)
+    );
+    return Math.floor(daysSincePrevStart / 7) + 1;
+  }
+
+  const data = Math.floor(daysSinceStart / 7) + 1;
+  return data;
 }

src/ethiopic/lib/getYear.test.ts

@@ -1 +1,5 @@
-test.todo("should return the correct Ethiopic year for a given date");
+describe("getYear", () => {
+  test.todo("should return correct Ethiopic year");
+
+  test.todo("should handle Ethiopic year boundary correctly");
+});

src/ethiopic/lib/isSameMonth.test.ts

@@ -1 +1,5 @@
-test.todo("isSameMonth should return true if two dates are in the same month");
+describe("isSameMonth", () => {
+  test.todo("should return true for dates in same Ethiopic month");
+  test.todo("should return false for dates in different Ethiopic months");
+  test.todo("should handle Ethiopic month boundaries correctly");
+});

src/ethiopic/lib/isSameYear.test.ts

@@ -1 +1,5 @@
-test.todo("isSameYear should return true if two dates are in the same year");
+describe("isSameYear", () => {
+  test.todo("should return true for dates in same Ethiopic year");
+  test.todo("should return false for dates in different Ethiopic years");
+  test.todo("should handle Ethiopic year boundary correctly");
+});

src/ethiopic/lib/newDate.test.ts

@@ -1,3 +1,3 @@
-describe("newDate", () => {
-  test.todo("should create a new Ethiopic date");
-});
+test.todo("creates date with valid Ethiopic values");
+test.todo("handles Pagume (13th month)");
+test.todo("throws error for invalid month");

src/ethiopic/lib/newDate.ts

@@ -9,5 +9,14 @@ import { toGregorianDate } from "../utils/index.js";
  * @returns {Date} The corresponding Gregorian date
  */
 export function newDate(year: number, monthIndex: number, date: number): Date {
-  return toGregorianDate({ year, month: monthIndex + 1, day: date });
+  // Convert from 0-based month index to 1-based Ethiopic month
+  const month = monthIndex + 1;
+
+  if (month < 1 || month > 13) {
+    throw new Error(
+      "Month must be between 0 and 12 (1-13 in Ethiopic calendar)"
+    );
+  }
+
+  return toGregorianDate({ year, month, day: date });
 }

src/ethiopic/lib/setYear.test.ts

@@ -1,3 +1,3 @@
-describe("setYear", () => {
-  test.todo("set the Ethiopic year for a given date");
-});
+test.todo("sets year correctly");
+test.todo("maintains month and day when possible");
+test.todo("adjusts day for leap year changes");