From 8f54e525b24fe00c41542cec0be6d4754030346c Mon Sep 17 00:00:00 2001
From: zhabinka <sergeykarpuk@yandex.by>
Date: Tue, 8 Jan 2019 16:21:09 +0300
Subject: [PATCH] Added converter to roman numerals

---
 .gitignore                                    | 12 +++
 javascript/package.json                       | 88 +++++++++++++++++++
 javascript/roman-numerals/roman-numerals.js   | 36 ++++++++
 .../roman-numerals/roman-numerals.spec.js     | 22 +++++
 4 files changed, 158 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 javascript/package.json
 create mode 100644 javascript/roman-numerals/roman-numerals.js
 create mode 100644 javascript/roman-numerals/roman-numerals.spec.js

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..a4a0b9b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,12 @@
+javascript/node_modules/
+javascript/package-lock.json
+
+javascript/*/README.md
+javascript/*/package.json
+*.exercism
+
+javascript/hello-world
+javascript/darts
+javascript/leap
+javascript/two-fer
+javascript/reverse-string
\ No newline at end of file
diff --git a/javascript/package.json b/javascript/package.json
new file mode 100644
index 0000000..38a89c3
--- /dev/null
+++ b/javascript/package.json
@@ -0,0 +1,88 @@
+{
+  "name": "exercism-javascript",
+  "version": "0.0.1",
+  "description": "Exercism exercises in Javascript.",
+  "author": "Katrina Owen",
+  "private": true,
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/exercism/javascript"
+  },
+  "devDependencies": {
+    "@babel/cli": "^7.1.0",
+    "@babel/core": "^7.1.0",
+    "@babel/node": "^7.0.0",
+    "@babel/preset-env": "^7.1.0",
+    "babel-core": "^7.0.0-0",
+    "babel-eslint": "^10.0.1",
+    "babel-jest": "^21.2.0",
+    "babel-plugin-transform-builtin-extend": "^1.1.2",
+    "babel-preset-env": "^1.7.0",
+    "eslint": "^5.6.0",
+    "eslint-config-airbnb-base": "^13.1.0",
+    "eslint-plugin-import": "^2.14.0",
+    "jest": "^23.6.0",
+    "cross-env": "^5.2.0"
+  },
+  "jest": {
+    "modulePathIgnorePatterns": [
+      "package.json"
+    ]
+  },
+  "babel": {
+    "presets": [
+      [
+        "env",
+        {
+          "targets": [
+            {
+              "node": "current"
+            }
+          ]
+        }
+      ]
+    ],
+    "plugins": [
+      [
+        "babel-plugin-transform-builtin-extend",
+        {
+          "globals": [
+            "Error"
+          ]
+        }
+      ],
+      [
+        "transform-regenerator"
+      ]
+    ]
+  },
+  "preferGlobal": true,
+  "scripts": {
+    "test": "jest --no-cache ./*",
+    "watch": "jest --no-cache --watch ./*",
+    "lint": "eslint .",
+    "lint-test": "eslint . && jest --no-cache ./* ",
+    "babel-node": "babel-node"
+  },
+  "eslintConfig": {
+    "parser": "babel-eslint",
+    "parserOptions": {
+      "ecmaVersion": 7,
+      "sourceType": "module"
+    },
+    "env": {
+      "es6": true,
+      "node": true,
+      "jest": true
+    },
+    "extends": "airbnb-base",
+    "rules": {
+      "import/no-unresolved": "off",
+      "import/extensions": "off",
+      "import/prefer-default-export": "off",
+      "import/no-default-export": "off"
+    }
+  },
+  "license": "MIT",
+  "dependencies": {}
+}
diff --git a/javascript/roman-numerals/roman-numerals.js b/javascript/roman-numerals/roman-numerals.js
new file mode 100644
index 0000000..332be3a
--- /dev/null
+++ b/javascript/roman-numerals/roman-numerals.js
@@ -0,0 +1,36 @@
+const romanCodes = {
+  M: 1000,
+  CM: 900,
+  D: 500,
+  CD: 400,
+  C: 100,
+  XC: 90,
+  L: 50,
+  XL: 40,
+  X: 10,
+  IX: 9,
+  V: 5,
+  IV: 4,
+  I: 1,
+};
+
+const getKeyByValue = (obj, value) => Object.keys(obj).find(key => obj[key] === value);
+
+const toRoman = (num) => {
+  const iter = (n, roman, i) => {
+    if (n === 0) {
+      return roman;
+    }
+
+    const currentArabic = Object.values(romanCodes)[i];
+    const currentRoman = getKeyByValue(romanCodes, currentArabic);
+
+    const resault = roman.concat(currentRoman.repeat(Math.floor(n / currentArabic)));
+
+    return iter(n % currentArabic, resault, i + 1);
+  };
+
+  return iter(num, '', 0);
+};
+
+export { toRoman };
diff --git a/javascript/roman-numerals/roman-numerals.spec.js b/javascript/roman-numerals/roman-numerals.spec.js
new file mode 100644
index 0000000..42dce59
--- /dev/null
+++ b/javascript/roman-numerals/roman-numerals.spec.js
@@ -0,0 +1,22 @@
+import { toRoman } from './roman-numerals';
+
+describe('toRoman()', () => {
+  test('converts 1', () => expect(toRoman(1)).toEqual('I'));
+  test('converts 2', () => expect(toRoman(2)).toEqual('II'));
+  test('converts 3', () => expect(toRoman(3)).toEqual('III'));
+  test('converts 4', () => expect(toRoman(4)).toEqual('IV'));
+  test('converts 5', () => expect(toRoman(5)).toEqual('V'));
+  test('converts 6', () => expect(toRoman(6)).toEqual('VI'));
+  test('converts 9', () => expect(toRoman(9)).toEqual('IX'));
+  test('converts 27', () => expect(toRoman(27)).toEqual('XXVII'));
+  test('converts 48', () => expect(toRoman(48)).toEqual('XLVIII'));
+  test('converts 59', () => expect(toRoman(59)).toEqual('LIX'));
+  test('converts 93', () => expect(toRoman(93)).toEqual('XCIII'));
+  test('converts 141', () => expect(toRoman(141)).toEqual('CXLI'));
+  test('converts 163', () => expect(toRoman(163)).toEqual('CLXIII'));
+  test('converts 402', () => expect(toRoman(402)).toEqual('CDII'));
+  test('converts 575', () => expect(toRoman(575)).toEqual('DLXXV'));
+  test('converts 911', () => expect(toRoman(911)).toEqual('CMXI'));
+  test('converts 1024', () => expect(toRoman(1024)).toEqual('MXXIV'));
+  test('converts 3000', () => expect(toRoman(3000)).toEqual('MMM'));
+});