[Fix] missing classNames from helpers

Author: JefteCaro

CONTRIBUTING.md

@@ -1,18 +1,22 @@
 # Contributing
 
-Thanks for your interest in contributing to `react-tailwindcss-datepicker`! Please take a moment to review this document **before submitting a pull request**.
+Thanks for your interest in contributing to `react-tailwindcss-datepicker`! Please take a moment to
+review this document **before submitting a pull request**.
 
-- [Pull requests](#pull-requests)
-- [Installation](#installation)
-- [Coding standards](#coding-standards)
-- [Running playground](#running-playgrounds)
-- [Before you make a Pull Request](#before-you-make-a-pull-request)
+-   [Pull requests](#pull-requests)
+-   [Installation](#installation)
+-   [Coding standards](#coding-standards)
+-   [Running playground](#running-playgrounds)
+-   [Before you make a Pull Request](#before-you-make-a-pull-request)
 
 ## Pull requests
 
 **Please ask first before starting work on any significant new features.**
 
-It's never a fun experience to have your pull request declined after investing a lot of time and effort into a new feature. To avoid this from happening, we request that contributors create [an issue](https://github.com/onesine/react-tailwindcss-datepicker/issues) to first discuss any significant new features.
+It's never a fun experience to have your pull request declined after investing a lot of time and
+effort into a new feature. To avoid this from happening, we request that contributors create
+[an issue](https://github.com/onesine/react-tailwindcss-datepicker/issues) to first discuss any
+significant new features.
 
 ## Installation
 
@@ -24,8 +28,8 @@ yarn install
 
 ## Coding standards
 
-We use `prettier` for making sure that the codebase is formatted consistently.
-To automatically fix any style violations in your code, you can run:
+We use `prettier` for making sure that the codebase is formatted consistently. To automatically fix
+any style violations in your code, you can run:
 
 **Using yarn**
 
@@ -61,16 +65,18 @@ npm dev
 
 ## Before you make a Pull Request
 
-We recommend to run these scripts in sequence before you make your commit message amd open a Pull Request
+We recommend to run these scripts in sequence before you make your commit message amd open a Pull
+Request
 
 **Let's clean the code first**
+
 ```sh
 yarn pret:fix
 ```
 
 **Test a build of your changes**
+
 ```sh
 yarn build
 
 ```
-

src/helpers/index.ts

@@ -2,6 +2,11 @@ import dayjs from "dayjs";
 import weekday from "dayjs/plugin/weekday";
 
 dayjs.extend(weekday);
+
+export function classNames(...classes: (false | null | undefined | string)[]) {
+    return classes.filter(Boolean).join(" ");
+}
+
 export function getTextColorByPrimaryColor(color: string) {
     switch (color) {
         case "blue":
@@ -165,6 +170,7 @@ export function getNumberOfDay(dayString: string, i18n: string, startWeekOn?: st
             }
         }
     );
+
     return number;
 }