Added file-extension utility

Author: Kathuria

README.md

@@ -39,9 +39,8 @@ This package includes various categorised validators which can be helppful for v
 13. **Social Insurance Number (SIN)**: For Canada or equivalent in other countries. (Upcoming)
 
 ### Formats and Patterns:
-14. **File Extensions**: Validate file names/extensions (e.g., `.jpg`, `.pdf`). (Upcoming)
+14. **File Extensions**: Validate file names/extensions (e.g., `.jpg`, `.pdf`).
 
 ### Additional Utility:
-15. **Boolean Strings**: Validate "true", "false", "1", "0", etc. (Upcoming)
-16. **Hex Color Codes**: Validate `#RRGGBB` or `#RGB` color formats.
-17. **EAN/UPC**: Validate international product codes. (Upcoming)
+15. **Hex Color Codes**: Validate `#RRGGBB` or `#RGB` color formats.
+16. **EAN/UPC**: Validate international product codes. (Upcoming)

USAGE_DETAILS.md

@@ -85,3 +85,14 @@ import { isValid_URL } from 'validate-functions/url';
 const urlWithQuery = 'http://example.com?name=value';
 console.log(isValid_URL(urlWithQuery)); // Output: true
 ```
+
+- **isValid_File_Extension**
+
+```typescript
+import { isValid_File_Extension } from 'validate-functions/file-extension';
+
+// Example of checking a file extension
+const fileName = 'document.pdf';
+const allowedExtensions = ['pdf', 'doc', 'txt'];
+console.log(isValid_File_Extension(fileName, allowedExtensions)); // Output: true if the extension is valid, false otherwise
+```

src/__tests__/file-extension.test.ts

@@ -0,0 +1,39 @@
+import { isValid_File_Extension } from '../file-extension';
+
+describe('File Extension Validation', () => {
+  it('should return true for a valid file extension', () => {
+    const fileName = 'document.pdf';
+    const allowedExtensions = ['pdf', 'doc', 'txt'];
+    expect(isValid_File_Extension(fileName, allowedExtensions)).toBe(true);
+  });
+
+  it('should return false for an invalid file extension', () => {
+    const fileName = 'image.jpeg';
+    const allowedExtensions = ['pdf', 'doc', 'txt'];
+    expect(isValid_File_Extension(fileName, allowedExtensions)).toBe(false);
+  });
+
+  it('should return false for a file with no extension', () => {
+    const fileName = 'file';
+    const allowedExtensions = ['pdf', 'doc', 'txt'];
+    expect(isValid_File_Extension(fileName, allowedExtensions)).toBe(false);
+  });
+
+  it('should return true for a valid file extension with mixed case', () => {
+    const fileName = 'presentation.PPT';
+    const allowedExtensions = ['ppt', 'doc', 'txt'];
+    expect(isValid_File_Extension(fileName, allowedExtensions)).toBe(true);
+  });
+
+  it('should return false for an empty file name', () => {
+    const fileName = '';
+    const allowedExtensions = ['pdf', 'doc', 'txt'];
+    expect(isValid_File_Extension(fileName, allowedExtensions)).toBe(false);
+  });
+
+  it('should return false for an empty allowed extensions list', () => {
+    const fileName = 'document.pdf';
+    const allowedExtensions: string[] = [];
+    expect(isValid_File_Extension(fileName, allowedExtensions)).toBe(false);
+  });
+});

src/__tests__/postal-zip.test.ts

@@ -256,8 +256,8 @@ describe('Postal Code Validation', () => {
   });
 
   describe('Invalid Country Code', () => {
-        it('should return false for an unsupported country code', () => {
-                expect(isValid_Postal_Code('awea23s', 'UN' as CountryCode)).toBe(false);
-        });
-        });    
+    it('should return false for an unsupported country code', () => {
+      expect(isValid_Postal_Code('awea23s', 'UN' as CountryCode)).toBe(false);
+    });
+  });
 });

src/file-extension.ts

@@ -0,0 +1,13 @@
+/**
+ *
+ * @param fileName
+ * @param allowedExtensions
+ * @returns
+ */
+export const isValid_File_Extension = (
+  fileName: string,
+  allowedExtensions: string[]
+): boolean => {
+  const extension = fileName.split('.').pop()?.toLowerCase() || '';
+  return allowedExtensions.includes(extension);
+};

src/hex-color.ts

@@ -1,10 +1,9 @@
 /**
  * A hex code, short for hexadecimal code, is a way of representing numbers using a base-16 numeral system.
- * @param color 
- * @returns 
+ * @param color
+ * @returns
  */
 export const isValid_Hex_Color = (color: string): boolean => {
-        const hexRegex = /^#([0-9a-fA-F]{3}|[0-9a-fA-F]{6})$/;
-        return hexRegex.test(color);
-      }
-      
+  const hexRegex = /^#([0-9a-fA-F]{3}|[0-9a-fA-F]{6})$/;
+  return hexRegex.test(color);
+};

src/index.ts

@@ -1,8 +1,9 @@
 export * from './aadhaar';
 export * from './credit-card';
 export * from './email';
+export * from './file-extension';
 export * from './ip';
 export * from './hex-color';
-export * from './postal-zip'
+export * from './postal-zip';
 export * from './ssn';
 export * from './url';

src/postal-zip.ts

@@ -24,7 +24,7 @@ export enum CountryCode {
   FR = 'FR', // France
   IT = 'IT', // Italy
   TZ = 'TZ', // Tanzania
-  ZA = 'ZA'  // South Africa
+  ZA = 'ZA', // South Africa
 }
 
 /**
@@ -33,7 +33,10 @@ export enum CountryCode {
  * @param countryCode - The country code as an enum.
  * @returns True if the postal code is valid for the given country, otherwise false.
  */
-export const isValid_Postal_Code = (postalCode: string, countryCode: CountryCode): boolean => {
+export const isValid_Postal_Code = (
+  postalCode: string,
+  countryCode: CountryCode
+): boolean => {
   const fiveDigitRegex = /^\d{5}$/;
   const sixDigitRegex = /^\d{6}$/;
   const fourDigitRegex = /^\d{4}$/;
@@ -63,7 +66,7 @@ export const isValid_Postal_Code = (postalCode: string, countryCode: CountryCode
     [CountryCode.FR]: fiveDigitRegex,
     [CountryCode.IT]: fiveDigitRegex,
     [CountryCode.TZ]: fiveDigitRegex,
-    [CountryCode.ZA]: fourDigitRegex
+    [CountryCode.ZA]: fourDigitRegex,
   };
 
   const regex = postalCodeRegexes[countryCode];

src/url.ts

@@ -4,6 +4,7 @@
  * @returns True if the URL is valid, otherwise false.
  */
 export const isValid_URL = (url: string): boolean => {
-  const urlRegex = /^(https?:\/\/)?([a-zA-Z0-9-]+\.)+[a-zA-Z]{2,}(:\d+)?(\/[^\s<>]*)?(\?[^\s<>]*)?(#[^\s<>]*)?$/i;
+  const urlRegex =
+    /^(https?:\/\/)?([a-zA-Z0-9-]+\.)+[a-zA-Z]{2,}(:\d+)?(\/[^\s<>]*)?(\?[^\s<>]*)?(#[^\s<>]*)?$/i;
   return urlRegex.test(url);
 };