[3.0.0] Add daysFrom and daysBetween helpers

We added these helpers that can calculate the number of days between two dates, either taking into account which comes first or not.

package.json

@@ -1,15 +1,15 @@
 {
 	"name": "fast-ts-helpers",
-	"version": "2.3.0",
+	"version": "3.0.0",
 	"private": true,
 	"description": "A package containing some helpful functions, constants, types, and react hooks.",
 	"license": "MIT",
 	"repository": "github:ericmakesapps/fast-ts-helpers",
 	"author": "Eric Ferreira <[email protected]>",
 	"scripts": {
 		"build": "tsc",
-		"check": "run-p lint format \"test -- --watchAll=false\"",
-		"fix": "run-s fix:lint fix:format \"test -- --watchAll=false\"",
+		"check": "run-p lint format \"test -- --watch=false\"",
+		"fix": "run-s fix:lint fix:format \"test -- --watch=false\"",
 		"fix:format": "npm run format -- --write",
 		"fix:lint": "npm run lint -- --fix",
 		"format": "prettier -c --ignore-path .gitignore \"**/?*.@(js|ts|jsx|tsx|json|md|html|css|scss)\"",

src/daysBetween.test.ts

@@ -0,0 +1,12 @@
+import daysBetween from "./daysBetween"
+import parseDate from "./parseDate"
+
+describe("keys helper", () => {
+	test("should return the positive number of days if `date` is before `toDate`", () => {
+		expect(daysBetween(parseDate("2023-01-01"), parseDate("2023-01-15"))).toEqual(14)
+	})
+
+	test("should return the positive number of days if `date` is after `toDate`", () => {
+		expect(daysBetween(parseDate("2023-01-11"), parseDate("2023-01-7"))).toEqual(4)
+	})
+})

src/daysBetween.ts

@@ -0,0 +1,8 @@
+import daysFrom from "./daysFrom"
+
+/** Get the number of days between the two passed dates, using UTC for each date (not counting the times of the dates). */
+function daysBetween(date: Date, andDate: Date) {
+	return Math.abs(daysFrom(date, andDate))
+}
+
+export default daysBetween

src/daysFrom.test.ts

@@ -0,0 +1,12 @@
+import daysFrom from "./daysFrom"
+import parseDate from "./parseDate"
+
+describe("keys helper", () => {
+	test("should return the positive number of days if `date` is before `toDate`", () => {
+		expect(daysFrom(parseDate("2023-01-01"), parseDate("2023-01-15"))).toEqual(14)
+	})
+
+	test("should return the negative number of days if `date` is after `toDate`", () => {
+		expect(daysFrom(parseDate("2023-01-11"), parseDate("2023-01-7"))).toEqual(-4)
+	})
+})

src/daysFrom.ts

@@ -0,0 +1,24 @@
+/** Get the number of days from one date to the next date, using UTC for each (not counting the times of the dates). If `date` is after `toDate`, the returned value will be negative. */
+function daysFrom(date: Date, toDate: Date) {
+	const d = new Date(
+		date.getUTCFullYear(),
+		date.getUTCMonth(),
+		date.getUTCDate(),
+		0,
+		0,
+		0
+	)
+
+	const d2 = new Date(
+		toDate.getUTCFullYear(),
+		toDate.getUTCMonth(),
+		toDate.getUTCDate(),
+		0,
+		0,
+		0
+	)
+
+	return Math.round((d2.getTime() - d.getTime()) / (1000 * 60 * 60 * 24))
+}
+
+export default daysFrom