feat: added imei validator

__tests__/luhn.test.ts

@@ -0,0 +1,44 @@
+import { Luhn } from '../src/luhn';
+
+describe('Luhn', () => {
+  const tests: [string, boolean][] = [
+    ['378282246310005', true],
+    ['371449635398431', true],
+    ['378734493671000', true],
+    ['5610591081018250', true],
+    ['30569309025904', true],
+    ['38520000023237', true],
+    ['6011111111111117', true],
+    ['6011000990139424', true],
+    ['3530111333300000', true],
+    ['3566002020360505', true],
+    ['5555555555554444', true],
+    ['5105105105105100', true],
+    ['4111111111111111', true],
+    ['4012888888881881', true],
+    ['4222222222222', true],
+    ['5019717010103742', true],
+    ['6331101999990016', true],
+
+    ['378282246310006', false],
+    ['371449635398432', false],
+    ['378734493671001', false],
+    ['5610591081018251', false],
+    ['30569309025905', false],
+    ['38520000023238', false],
+    ['6011111111111118', false],
+    ['6011000990139425', false],
+    ['3530111333300001', false],
+    ['3566002020360506', false],
+    ['5555555555554445', false],
+    ['5105105105105101', false],
+    ['4111111111111112', false],
+    ['4012888888881882', false],
+    ['4222222222223', false],
+    ['5019717010103743', false],
+    ['6331101999990017', false],
+  ];
+  test.each(tests)(`Check %s => %s`, (value, expected) => {
+    expect(Luhn.validate(value)).toBe(expected);
+  });
+});

__tests__/validator.test.ts

@@ -110,3 +110,21 @@ describe('ESIC', () => {
     expect(Validator.esic(value)).toBe(expected);
   });
 });
+
+describe('IMEI', () => {
+  const tests: [string, boolean][] = [
+    ['49-015420-323751-8', true],
+    ['490154203237518', true],
+    ['356938035643809', true],
+
+    ['49-015420-323751-9', false],
+    ['490154203237519', false],
+    ['4901542032375191', false],
+    ['49015420323751', false],
+    ['a49015420323751', false],
+    ['49015420323751a', false],
+  ];
+  test.each(tests)(`Check %s => %s`, (value, expected) => {
+    expect(Validator.imei(value)).toBe(expected);
+  });
+});

src/luhn.ts

@@ -0,0 +1,16 @@
+export class Luhn {
+  static validate(value: string): boolean {
+    const digits = [...value.replace(/\s/g, '')].reverse();
+
+    const sum = digits
+      .map((digit: number | string, index) => {
+        digit = parseInt(digit as string, 10) * (index % 2 !== 0 ? 2 : 1);
+        return digit > 9 ? digit - 9 : digit;
+      })
+      .reduce((prev, current) => {
+        return prev + current;
+      });
+
+    return sum > 0 && sum % 10 === 0;
+  }
+}

src/validator.ts

@@ -1,3 +1,5 @@
+import { Luhn } from './luhn';
+
 export class Validator {
   static mobile(value: string): boolean {
     return /^[6789]\d{9}$/.test(value);
@@ -26,4 +28,9 @@ export class Validator {
   static esic(value: string): boolean {
     return /^\d{17}$/.test(value);
   }
+
+  static imei(value: string): boolean {
+    value = value.replace(/[\s-]+/g, '');
+    return /^\d{15}$/.test(value) && Luhn.validate(value);
+  }
 }