extend returning format of getDateOfBirth

package.json

@@ -1,68 +1,68 @@
 {
-	"name": "pesel-utils",
-	"version": "1.0.4",
-	"description": "Bunch of utilities useful when working with PESEL numbers",
-	"main": "dist/index.js",
-	"module": "dist/index.esm.js",
-	"types": "dist/index.d.ts",
-	"files": [
-		"dist/index.js",
-		"dist/index.esm.js",
-		"dist/index.d.ts"
-	],
-	"author": "Antoni Kepinski <a@kepinski.me> (https://kepinski.me)",
-	"bugs": {
-		"url": "https://github.com/xxczaki/pesel-utils/issues"
-	},
-	"scripts": {
-		"prebuild": "del-cli dist",
-		"esm": "tsc --module esnext && cpy dist/index.js dist --rename index.esm.js",
-		"cjs": "tsc --module commonjs",
-		"build": "npm run esm && npm run cjs",
-		"test": "npm run build && xo && ava",
-		"prepublishOnly": "npm run build"
-	},
-	"engines": {
-		"node": ">=8"
-	},
-	"license": "MIT",
-	"repository": "xxczaki/pesel-utils",
-	"homepage": "https://github.com/xxczaki/pesel-utils",
-	"devDependencies": {
-		"@akepinski/tsconfig": "0.0.2",
-		"@typescript-eslint/eslint-plugin": "^1.13.0",
-		"@typescript-eslint/parser": "^1.13.0",
-		"ava": "^2.4.0",
-		"browser-env": "^3.2.6",
-		"cpy-cli": "^2.0.0",
-		"del-cli": "^3.0.0",
-		"eslint-config-xo-typescript": "^0.15.0",
-		"ts-node": "^8.4.1",
-		"typescript": "^3.6.3",
-		"xo": "*"
-	},
-	"sideEffects": false,
-	"ava": {
-		"babel": false,
-		"compileEnhancements": false,
-		"extensions": [
-			"ts"
-		],
-		"require": [
-			"ts-node/register"
-		]
-	},
-	"xo": {
-		"extends": "xo-typescript",
-		"envs": [
-			"browser"
-		],
-		"extensions": [
-			"ts"
-		],
-		"rules": {
-			"no-mixed-operators": "off",
-			"ava/no-ignored-test-files": "off"
-		}
-	}
+  "name": "pesel-utils",
+  "version": "1.0.4",
+  "description": "Bunch of utilities useful when working with PESEL numbers",
+  "main": "dist/index.js",
+  "module": "dist/index.esm.js",
+  "types": "dist/index.d.ts",
+  "files": [
+    "dist/index.js",
+    "dist/index.esm.js",
+    "dist/index.d.ts"
+  ],
+  "author": "Antoni Kepinski <a@kepinski.me> (https://kepinski.me)",
+  "bugs": {
+    "url": "https://github.com/xxczaki/pesel-utils/issues"
+  },
+  "scripts": {
+    "prebuild": "del-cli dist",
+    "esm": "tsc --module esnext && cpy dist/index.js dist --rename index.esm.js",
+    "cjs": "tsc --module commonjs",
+    "build": "npm run esm && npm run cjs",
+    "test": "npm run build && xo && ava",
+    "prepublishOnly": "npm run build"
+  },
+  "engines": {
+    "node": ">=8"
+  },
+  "license": "MIT",
+  "repository": "xxczaki/pesel-utils",
+  "homepage": "https://github.com/xxczaki/pesel-utils",
+  "devDependencies": {
+    "@akepinski/tsconfig": "0.0.2",
+    "@typescript-eslint/eslint-plugin": "^1.13.0",
+    "@typescript-eslint/parser": "^1.13.0",
+    "ava": "^2.4.0",
+    "browser-env": "^3.2.6",
+    "cpy-cli": "^2.0.0",
+    "del-cli": "^3.0.0",
+    "eslint-config-xo-typescript": "^0.15.0",
+    "ts-node": "^8.4.1",
+    "typescript": "^3.6.3",
+    "xo": "*"
+  },
+  "sideEffects": false,
+  "ava": {
+    "babel": false,
+    "compileEnhancements": false,
+    "extensions": [
+      "ts"
+    ],
+    "require": [
+      "ts-node/register"
+    ]
+  },
+  "xo": {
+    "extends": "xo-typescript",
+    "envs": [
+      "browser"
+    ],
+    "extensions": [
+      "ts"
+    ],
+    "rules": {
+      "no-mixed-operators": "off",
+      "ava/no-ignored-test-files": "off"
+    }
+  }
 }

readme.md

@@ -2,32 +2,55 @@
 
 > Bunch of utilities useful when working with PESEL numbers
 
-[![Build Status](https://travis-ci.org/xxczaki/pesel-utils.svg?branch=master)](https://travis-ci.org/xxczaki/pesel-utils) 
-[![XO code style](https://img.shields.io/badge/code_style-XO-5ed9c7.svg)](https://github.com/xojs/xo) 
+[![Build Status](https://travis-ci.org/xxczaki/pesel-utils.svg?branch=master)](https://travis-ci.org/xxczaki/pesel-utils)
+[![XO code style](https://img.shields.io/badge/code_style-XO-5ed9c7.svg)](https://github.com/xojs/xo)
 [![install size](https://packagephobia.now.sh/badge?p=pesel-utils)](https://packagephobia.now.sh/result?p=pesel-utils)
 
 ## Highlights
 
 - Simple API
-- 0 dependencies
+- Zero dependencies
 - Well tested
-- Uses 4-step PESEL validation (lenght + year + month + checksum)
+- Uses 4-step PESEL validation (length + year + month + checksum)
 - Written in TypeScript
 
 ## Install
 
 ```
-$ npm install pesel-utils
+npm install pesel-utils
+```
+
+or
+
+```
+yarn add pesel-utils
 ```
 
 ## Usage
 
+Add utils to your project
+
 ```js
-const {isValidPesel, checkGender, getDateOfBirth} = require('pesel-utils');
+const { isValidPesel, checkGender, getDateOfBirth } = require("pesel-utils");
+```
+
+or
 
-isValidPesel('371340514609'); //=> false
-checkGender('69021818876'); //=> 'male'
-getDateOfBirth('75040373939'); //=> '1975/04/03'
+```js
+import { checkGender, getDateOfBirth, isValidPesel } from "pesel-utils";
+```
+
+then
+
+```js
+isValidPesel("371340514609"); // => false
+checkGender("69021818876"); // => 'male'
+
+getDateOfBirth("75040373939"); // => '1975/04/03'
+// You can also specify a separator
+getDateOfBirth("75040373939", "-"); // => '1975-04-03'
+// or get it as array
+getDateOfBirth("75040373939", null); // => ['1975', '04', '03']
 ```
 
 ## API
@@ -52,16 +75,24 @@ Type: `string`
 
 PESEL you want to check.
 
-### getDateOfBirth(pesel)
+### getDateOfBirth(pesel, separator?)
+
+Returns a `string` with date of birth, extracted from PESEL in [ISO 8601](https://www.iso.org/iso-8601-date-and-time-format.html) format by default.
 
-Returns a `string` with date of birth, extracted from PESEL (in [ISO 8601](https://www.iso.org/iso-8601-date-and-time-format.html) format).
+You can specify custom separator or get it as array (just set `null`).
 
 ##### pesel
 
 Type: `string`
 
 PESEL you want to check.
 
+##### separator
+
+Type: `string`
+
+Default is `/`. If you want to get Array, set it to `null`.
+
 ## License
 
 MIT © [Antoni Kepinski](https://kepinski.me)

src/index.ts

@@ -1,47 +1,46 @@
-'use strict';
-
 /**
-* @param {string} pesel PESEL you want to check.
-* @return {boolean} Whether the provided PESEL is valid or not.
-*/
+ * @param {string} pesel - PESEL you want to check.
+ * @return {boolean} Whether the provided PESEL is valid or not.
+ */
 const isValidPesel = (pesel: string): boolean => {
-	// Basic validation
-	if (pesel.length !== 11) {
+	// Basic validation.
+	if (!/^[0-9]{11}$/u.test(pesel)) {
 		return false;
 	}
 
-	const arr = pesel.split('').map(e => Number(e));
-
-	const year = Number(`${arr[0]}${arr[1]}`);
-	const month = Number(`${arr[2]}${arr[3]}`);
+	const monthWithCentury = Number(pesel.substring(2, 4));
 
-	// Year validation
-	if (year <= 0o0 || year > 99) {
+	// Century is encoded in month: https://en.wikipedia.org/wiki/PESEL.
+	if (!monthWithCentury || monthWithCentury % 20 > 12) {
 		return false;
 	}
 
-	// Month validation
-	if (month <= 0o0 || month > 72) {
+	// Validate day.
+	const day = Number(pesel.substring(4, 6));
+	if (!day || day < 1 || day > 31) {
 		return false;
 	}
 
-	const validate = ((9 * arr[0]) + (7 * arr[1]) + (3 * arr[2]) + arr[3] + (9 * arr[4]) + (7 * arr[5]) + (3 * arr[6]) + arr[7] + (9 * arr[8]) + (7 * arr[9]));
-	const lastDigit = Number(validate.toString().split('').pop());
+	const times = [1, 3, 7, 9];
+	const digits: number[] = `${pesel}`
+		.split('')
+		.map(digit => Number.parseInt(digit, 10));
 
-	// Checksum check
-	if (lastDigit === arr[10]) {
-		return true;
-	}
+	const [dig11] = digits.splice(-1);
 
-	return false;
+	const control = digits.reduce((previousValue, currentValue, index) =>
+		previousValue + currentValue * times[index % 4] as number
+	) % 10;
+
+	return 10 - (control === 0 ? 10 : control) === dig11;
 };
 
 /**
-* @param {string} pesel PESEL you want to check.
-* @return {('male'|'female')} Gender (`male` or `female`).
-*/
+ * @param {string} pesel - PESEL you want to check.
+ * @return {('male'|'female')} Gender (`male` or `female`).
+ */
 const checkGender = (pesel: string): 'male' | 'female' => {
-	const arr = pesel.split('').map(e => Number(e));
+	const arr = pesel.split('').map(Number);
 
 	const genderIdentifier = arr[9];
 
@@ -53,11 +52,15 @@ const checkGender = (pesel: string): 'male' | 'female' => {
 };
 
 /**
-* @param {string} pesel PESEL you want to check.
-* @return {string} Date of birth, extracted from PESEL (in ISO 8601 format).
-*/
-const getDateOfBirth = (pesel: string): string => {
-	const arr = pesel.split('').map(e => Number(e));
+ * @param {string} pesel - PESEL you want to check.
+ * @param {string} separator - default is `/`. If you want to get Array, set it to `null`.
+ * @return {string | array} Date of birth, extracted from PESEL in ISO 8601 format by default, also you can add custom separator. If separator is `null` it returns Array.
+ */
+const getDateOfBirth = (
+	pesel: string,
+	separator: string | null = '/',
+): string | string[] => {
+	const arr = pesel.split('').map(Number);
 
 	const year = `${arr[0]}${arr[1]}`;
 	const month = Number(`${arr[2]}${arr[3]}`);
@@ -91,11 +94,13 @@ const getDateOfBirth = (pesel: string): string => {
 		formattedMonth = month - 60;
 	}
 
-	return `${firstDigitsofTheYear}${year}/${formattedMonth < 10 ? `0${formattedMonth}` : formattedMonth}/${day}`;
-};
+	const birthDate: string[] = [
+		`${firstDigitsofTheYear}${year}`,
+		`${formattedMonth < 10 ? `0${formattedMonth}` : formattedMonth}`,
+		`${day}`,
+	];
 
-export {
-	isValidPesel,
-	checkGender,
-	getDateOfBirth
+	return separator ? birthDate.join(separator) : birthDate;
 };
+
+export {isValidPesel, checkGender, getDateOfBirth};

test.ts

@@ -41,6 +41,15 @@ test('get date of birth (21st century)', t => {
 test('get date of birth (22nd century)', t => {
 	t.is(getDateOfBirth('00440345653'), '2100/04/03');
 });
+
 test('get date of birth (23rd century)', t => {
 	t.is(getDateOfBirth('00640345653'), '2200/04/03');
 });
+
+test('get date of birth (21st century) with custom separator', t => {
+	t.is(getDateOfBirth('13240376213', '-'), '2013/04/03');
+});
+
+test('get date of birth (22nd century) as array', t => {
+	t.is(getDateOfBirth('00440345653', null), ['2100', '04', '03']);
+});