479/holidays within (#480)

* feat(#479): holidaysWithinInterval

* docs(#479): add holidaysWithinInterval

README.md

@@ -74,20 +74,52 @@ const currentYearHolidays = colombianHolidays();
 
 ## Utils
 
-The package provides the `isHoliday` helper which can be imported from `lib/utils`:
+The package provides two helper functions which can be imported from `lib/utils`:
+
+### isHoliday
+
+Returns true if the given date is a colombian holiday, otherwise returns false.
 
 ```js
-import { isHoliday } from 'colombian-holidays/lib/utils`
+import { isHoliday } from 'colombian-holidays/lib/utils/isHoliday`
 
 const date = new Date("2018-01-01T05:00:00.000Z")
 
 if (isHoliday(date)) {
-  console.log('it is holiday');
+  console.log('it is a colombian holiday');
 } else {
-  console.log('it is not');
+  console.log('it is NOT a colombian holiday');
 }
 ```
 
+### holidaysWithinInterval
+
+Returns an with the colombian holidays within two dates:
+
+```js
+import { holidaysWithinInterval } from 'colombian-holidays/lib/utils/holidaysWithinInterval`
+
+const start = new Date("2021-01-01");
+const end = new Date("2021-01-11");
+const holidays = holidaysWithinInterval({ start, end });
+/*
+[
+  {
+    celebrationDate: "2021-01-01",
+    date: "2021-01-01",
+    name: "Año Nuevo",
+    nextMonday: false,
+  },
+  {
+    celebrationDate: "2021-01-11",
+    date: "2021-01-06",
+    name: "Reyes Magos",
+    nextMonday: true,
+  },
+]
+*/
+```
+
 ### TypeScript
 
 The module is written in TypeScript and type definitions files are included.

src/utils/holidaysWithinInterval.test.ts

@@ -0,0 +1,73 @@
+import { holidaysWithinInterval } from "./holidaysWithinInterval";
+
+describe("holidaysWithinInterval", () => {
+  it("should return the correct number of holidays overlapping two years", () => {
+    const start = new Date("2020-12-01");
+    const end = new Date("2021-01-15");
+    const result = holidaysWithinInterval({ end, start });
+
+    expect(result).toEqual([
+      {
+        celebrationDate: "2020-12-08",
+        date: "2020-12-08",
+        name: "Inmaculada Concepción",
+        nextMonday: false,
+      },
+      {
+        celebrationDate: "2020-12-25",
+        date: "2020-12-25",
+        name: "Navidad",
+        nextMonday: false,
+      },
+      {
+        celebrationDate: "2021-01-01",
+        date: "2021-01-01",
+        name: "Año Nuevo",
+        nextMonday: false,
+      },
+      {
+        celebrationDate: "2021-01-11",
+        date: "2021-01-06",
+        name: "Reyes Magos",
+        nextMonday: true,
+      },
+    ]);
+  });
+
+  it("should return the correct number of holidays inclusive", () => {
+    const start = new Date("2021-01-01");
+    const end = new Date("2021-01-11");
+    const result = holidaysWithinInterval({ start, end });
+
+    expect(result).toEqual([
+      {
+        celebrationDate: "2021-01-01",
+        date: "2021-01-01",
+        name: "Año Nuevo",
+        nextMonday: false,
+      },
+      {
+        celebrationDate: "2021-01-11",
+        date: "2021-01-06",
+        name: "Reyes Magos",
+        nextMonday: true,
+      },
+    ]);
+  });
+
+  it("should return the correct number of holidays for a given year", () => {
+    const start = new Date("2021-01-01");
+    const end = new Date("2021-12-31");
+    const result = holidaysWithinInterval({ start, end });
+
+    expect(result.length).toBe(18);
+  });
+
+  it("should return the correct number of holidays overlapping three years", () => {
+    const start = new Date("2014-07-20");
+    const end = new Date("2016-03-25");
+    const result = holidaysWithinInterval({ start, end });
+
+    expect(result.length).toBe(31);
+  });
+});

src/utils/holidaysWithinInterval.ts

@@ -0,0 +1,24 @@
+import colombianHolidays from "..";
+import { ColombianHoliday } from "../types";
+
+export type Interval = {
+  start: Date;
+  end: Date;
+};
+export function holidaysWithinInterval({
+  start,
+  end,
+}: Interval): ColombianHoliday[] {
+  const yearEnd = new Date(end).getUTCFullYear();
+  const yearStart = new Date(start).getUTCFullYear();
+  let holidays: ColombianHoliday[] = [];
+
+  for (let i = yearStart; i <= yearEnd; i += 1) {
+    holidays = holidays.concat(colombianHolidays(i));
+  }
+
+  return holidays.filter(({ celebrationDate }) => {
+    const date = new Date(celebrationDate);
+    return date >= start && date <= end;
+  });
+}

src/utils.test.ts → src/utils/isHoliday.test.ts

@@ -1,4 +1,4 @@
-import { isHoliday } from "./utils";
+import { isHoliday } from "./isHoliday";
 
 describe("test isHoliday", () => {
   it(`should return true for a holiday date object`, () => {

src/utils.ts → src/utils/isHoliday.ts

@@ -1,4 +1,4 @@
-import colombianHolidays from ".";
+import colombianHolidays from "..";
 
 export function isHoliday(date: Date): boolean {
   return colombianHolidays(date.getUTCFullYear()).some(