feat: isValidImage gif validation

packages/typescript/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "multiform-validator",
-	"version": "2.0.3",
+	"version": "2.0.4",
 	"description": "Javascript library made to validate, several form fields, such as: email, phone, password, cpf etc.",
 	"main": "./dist/index.js",
 	"types": "./types/index.d.ts",

packages/typescript/src/isValidImage.ts

@@ -8,13 +8,20 @@ function isValidImage(fileBuffer: Buffer): boolean {
 	// Check magic numbers to determine the mimetype
 	const isJpeg: boolean =
 		fileBuffer[0] === 0xff && fileBuffer[1] === 0xd8 && fileBuffer[2] === 0xff;
+
 	const isPng: boolean =
 		fileBuffer[0] === 0x89 &&
 		fileBuffer[1] === 0x50 &&
 		fileBuffer[2] === 0x4e &&
 		fileBuffer[3] === 0x47;
 
-	return isJpeg || isPng;
+	const isGif: boolean =
+		fileBuffer[0] == 0x47 &&
+		fileBuffer[1] == 0x49 &&
+		fileBuffer[2] == 0x46 &&
+		fileBuffer[3] == 0x38;
+
+	return isJpeg || isPng || isGif;
 }
 
 export default isValidImage;

packages/typescript/tests/src/isValidImage.test.ts

@@ -18,5 +18,35 @@ describe('isValidImage', () => {
 		const result = isValidImage(fileBuffer);
 		expect(result).toBe(false);
 	});
+
+	it('should return false for a GIF image', () => {
+		const fileBuffer = Buffer.from([0x47, 0x49, 0x46, 0x38, /* ... */]);
+		const result = isValidImage(fileBuffer);
+		expect(result).toBe(true);
+	});
+
+	it('should return false for an empty buffer', () => {
+		const fileBuffer = Buffer.from([]);
+		const result = isValidImage(fileBuffer);
+		expect(result).toBe(false);
+	});
+
+	it('should return false for a buffer with less than 4 bytes', () => {
+		const fileBuffer = Buffer.from([0x47, 0x49, 0x46]);
+		const result = isValidImage(fileBuffer);
+		expect(result).toBe(false);
+	});
+
+	it('should return false for a buffer with less than 3 bytes', () => {
+		const fileBuffer = Buffer.from([0x47, 0x49]);
+		const result = isValidImage(fileBuffer);
+		expect(result).toBe(false);
+	});
+
+	it('should return false for a buffer with less than 2 bytes', () => {
+		const fileBuffer = Buffer.from([0x47]);
+		const result = isValidImage(fileBuffer);
+		expect(result).toBe(false);
+	});
 });
 export default isValidImage;