From 533bcaf826cc466a30b99bca457e6c8d14900231 Mon Sep 17 00:00:00 2001
From: Oliver Davies <oliver@oliverdavies.uk>
Date: Fri, 3 Jul 2020 20:39:28 +0100
Subject: [PATCH] Roman numeral converter
---
composer.json | 3 +
composer.lock | 67 ++++++++++++-
src/RomanNumeralsConverter.php | 50 ++++++++++
tests/RomanNumeralsConverterTest.php | 142 +++++++++++++++++++++++++++
4 files changed, 260 insertions(+), 2 deletions(-)
create mode 100644 src/RomanNumeralsConverter.php
create mode 100644 tests/RomanNumeralsConverterTest.php
diff --git a/composer.json b/composer.json
index 0f09d08..be4d09c 100644
--- a/composer.json
+++ b/composer.json
@@ -1,6 +1,9 @@
{
"minimum-stability": "dev",
"prefer-stable": true,
+ "require": {
+ "beberlei/assert": "^3.2"
+ },
"require-dev": {
"phpunit/phpunit": "^9.0"
},
diff --git a/composer.lock b/composer.lock
index 06e4fb5..41e757b 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,8 +4,71 @@
"Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
"This file is @generated automatically"
],
- "content-hash": "73cde71d5e2a36a709acfdfab2ad5dfb",
- "packages": [],
+ "content-hash": "7aa2245203ff9ea2bce7a2e52abd5654",
+ "packages": [
+ {
+ "name": "beberlei/assert",
+ "version": "v3.2.7",
+ "source": {
+ "type": "git",
+ "url": "https://github.com/beberlei/assert.git",
+ "reference": "d63a6943fc4fd1a2aedb65994e3548715105abcf"
+ },
+ "dist": {
+ "type": "zip",
+ "url": "https://api.github.com/repos/beberlei/assert/zipball/d63a6943fc4fd1a2aedb65994e3548715105abcf",
+ "reference": "d63a6943fc4fd1a2aedb65994e3548715105abcf",
+ "shasum": ""
+ },
+ "require": {
+ "ext-ctype": "*",
+ "ext-json": "*",
+ "ext-mbstring": "*",
+ "ext-simplexml": "*",
+ "php": "^7"
+ },
+ "require-dev": {
+ "friendsofphp/php-cs-fixer": "*",
+ "phpstan/phpstan-shim": "*",
+ "phpunit/phpunit": ">=6.0.0 <8"
+ },
+ "suggest": {
+ "ext-intl": "Needed to allow Assertion::count(), Assertion::isCountable(), Assertion::minCount(), and Assertion::maxCount() to operate on ResourceBundles"
+ },
+ "type": "library",
+ "autoload": {
+ "psr-4": {
+ "Assert\\": "lib/Assert"
+ },
+ "files": [
+ "lib/Assert/functions.php"
+ ]
+ },
+ "notification-url": "https://packagist.org/downloads/",
+ "license": [
+ "BSD-2-Clause"
+ ],
+ "authors": [
+ {
+ "name": "Benjamin Eberlei",
+ "email": "kontakt@beberlei.de",
+ "role": "Lead Developer"
+ },
+ {
+ "name": "Richard Quadling",
+ "email": "rquadling@gmail.com",
+ "role": "Collaborator"
+ }
+ ],
+ "description": "Thin assertion library for input validation in business models.",
+ "keywords": [
+ "assert",
+ "assertion",
+ "validation"
+ ],
+ "time": "2019-12-19T17:51:41+00:00"
+ }
+ ],
"packages-dev": [
{
"name": "doctrine/instantiator",
diff --git a/src/RomanNumeralsConverter.php b/src/RomanNumeralsConverter.php
new file mode 100644
index 0000000..07eabe4
--- /dev/null
+++ b/src/RomanNumeralsConverter.php
@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App;
+
+use Assert\Assert;
+
+final class RomanNumeralsConverter
+{
+ private static $map = [
+ 1000 => 'M',
+ 900 => 'CM',
+ 500 => 'D',
+ 400 => 'CD',
+ 100 => 'C',
+ 90 => 'XC',
+ 50 => 'L',
+ 40 => 'XL',
+ 10 => 'X',
+ 9 => 'IX',
+ 5 => 'V',
+ 4 => 'IV',
+ 3 => 'III',
+ 2 => 'II',
+ 1 => 'I',
+ ];
+
+ public static function convert(int $input): string
+ {
+ Assert::that($input)
+ ->greaterOrEqualThan(0, 'Cannot convert negative numbers');
+
+ $letters = '';
+
+ while ($input > 0) {
+ foreach (static::$map as $number => $letter) {
+ if ($input >= $number) {
+ // Add the appropriate numeral and reduce the value of
+ // $input accordingly.
+ $letters .= $letter;
+ $input = ($input - $number);
+ break;
+ }
+ }
+ }
+
+ return $letters;
+ }
+}
diff --git a/tests/RomanNumeralsConverterTest.php b/tests/RomanNumeralsConverterTest.php
new file mode 100644
index 0000000..e3227f9
--- /dev/null
+++ b/tests/RomanNumeralsConverterTest.php
@@ -0,0 +1,142 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests;
+
+use App\RomanNumeralsConverter;
+use Assert\AssertionFailedException;
+use PHPUnit\Framework\Assert;
+use PHPUnit\Framework\TestCase;
+
+final class RomanNumeralsConverterTest extends TestCase
+{
+ /**
+ * @test
+ * @dataProvider numeralProvider
+ */
+ public function it_converts_a_number(int $number, string $expected): void
+ {
+ Assert::assertSame(
+ $expected,
+ RomanNumeralsConverter::convert($number)
+ );
+ }
+
+ public function numeralProvider(): array
+ {
+ return [
+ 1 => [
+ 'number' => 1,
+ 'expected' => 'I',
+ ],
+ 2 => [
+ 'number' => 2,
+ 'expected' => 'II',
+ ],
+ 3 => [
+ 'number' => 3,
+ 'expected' => 'III',
+ ],
+ 4 => [
+ 'number' => 4,
+ 'expected' => 'IV',
+ ],
+ 5 => [
+ 'number' => 5,
+ 'expected' => 'V',
+ ],
+ 9 => [
+ 'number' => 9,
+ 'expected' => 'IX',
+ ],
+ 10 => [
+ 'number' => 10,
+ 'expected' => 'X',
+ ],
+ 15 => [
+ 'number' => 15,
+ 'expected' => 'XV',
+ ],
+ 19 => [
+ 'number' => 19,
+ 'expected' => 'XIX',
+ ],
+ 20 => [
+ 'number' => 20,
+ 'expected' => 'XX',
+ ],
+ 21 => [
+ 'number' => 21,
+ 'expected' => 'XXI',
+ ],
+ 40 => [
+ 'number' => 40,
+ 'expected' => 'XL',
+ ],
+ 50 => [
+ 'number' => 50,
+ 'expected' => 'L',
+ ],
+ 80 => [
+ 'number' => 80,
+ 'expected' => 'LXXX',
+ ],
+ 90 => [
+ 'number' => 90,
+ 'expected' => 'XC',
+ ],
+ 100 => [
+ 'number' => 100,
+ 'expected' => 'C',
+ ],
+ 110 => [
+ 'number' => 110,
+ 'expected' => 'CX',
+ ],
+ 400 => [
+ 'number' => 400,
+ 'expected' => 'CD',
+ ],
+ 500 => [
+ 'number' => 500,
+ 'expected' => 'D',
+ ],
+ 700 => [
+ 'number' => 700,
+ 'expected' => 'DCC',
+ ],
+ 900 => [
+ 'number' => 900,
+ 'expected' => 'CM',
+ ],
+ 1000 => [
+ 'number' => 1000,
+ 'expected' => 'M',
+ ],
+ 1986 => [
+ 'number' => 1986,
+ 'expected' => 'MCMLXXXVI',
+ ],
+ 1990 => [
+ 'number' => 1990,
+ 'expected' => 'MCMXC',
+ ],
+ 2020 => [
+ 'number' => 2020,
+ 'expected' => 'MMXX',
+ ],
+ ];
+ }
+
+ /**
+ * @test
+ */
+ public function it_cannot_convert_negative_numbers(): void
+ {
+ $this->expectException(AssertionFailedException::class);
+ $this->expectExceptionMessage('Cannot convert negative numbers');
+
+ RomanNumeralsConverter::convert(-1);
+ }
+}