Typescript: Get current weekdays

app.ts

// v1.0.1

// consts
const weekInMs = 1000 * 60 * 60 * 24 * 7;
const dayInMs = 1000 * 60 * 60 * 24;

// main function
const getWeekArray = (currentDate: Date, page: number) => {
 if (page > 0) {
  currentDate = new Date(currentDate.getTime() + weekInMs * page); // Add X weeks where X is page
 } else if (page < 0) {
  currentDate = new Date(currentDate.getTime() - weekInMs * (page * -1)); // Subtract X weeks where X is page
 } else {
  // page = 1 is already fine
 }

 // currentDate now includes pagination. We have any day inside correct week

 // Get closest monday in the past
 const mondayDate = new Date(currentDate.getTime());
 if (currentDate.getDay() == 0) {
  mondayDate.setDate(currentDate.getDate() - 7);
 } else {
  mondayDate.setDate(currentDate.getDate() - (currentDate.getDay() - 1));
 }

 // Prepare result, 7 days of the week
 const mondayDateInMs = mondayDate.getTime();

 const daysOfWeek = Array.from(Array(7).keys()).map((dayIndex) => {
  return new Date(mondayDateInMs + dayInMs * dayIndex);
 });

 return daysOfWeek;
};

// Main code
// Page 0 means first page
const dateNow = new Date();
for (const page of [-3, -2, -1, 0, 1, 2, 3]) {
 console.log(`Page ${page}:`, getWeekArray(dateNow, page));
}