Implemented two functions: rotateMatrix(arr) and dragonCurve(n) with tests

babel.config.js

@@ -0,0 +1,5 @@
+'use strict';
+
+module.exports = {
+  presets: ['@babel/preset-env'],
+};

package.json

@@ -3,14 +3,11 @@
   "version": "1.0.0",
   "description": "",
   "main": "index.js",
-  "scripts": {
-    "start": "webpack-dev-server --config ./webpack/webpack.dev.js --open HOST=0.0.0.0",
+  "scripts": {    
     "test": "jest",
     "lint": "eslint ./src",
     "lint:watch": "esw --watch",
-    "stylelint": "stylelint './src/**/*.css'",
-    "precommit": "npm run lint && npm run stylelint",
-    "prepush": "npm run test"
+    "stylelint": "stylelint './src/**/*.css'"    
   },
   "repository": {
     "type": "git",
@@ -30,6 +27,10 @@
     "html-webpack-plugin": "^3.2.0",
     "husky": "^1.1.2",
     "jest": "^23.6.0",
+    "@babel/core": "*",
+    "@babel/preset-env": "*",
+    "babel-core": "7.0.0-bridge.0",
+    "babel-jest": "*",
     "node-sass": "^4.9.4",
     "sass-loader": "^7.1.0",
     "style-loader": "^0.23.1",

src/dragon-curve/index.js

@@ -1,3 +1,20 @@
 export const dragonCurve = n => {
-  // logic...
-};
+
+  const reverseString = string => {     
+    return string.split('')
+      .map(el => {
+        return el === '1' ? '0' : '1';
+      })  
+      .reverse()
+      .join('');
+  }; 
+
+  let dragonRow = '1';
+
+  n -= 1;
+  while (n > 0){
+    dragonRow += '1' + reverseString(dragonRow);
+    n -= 1;
+  }
+  return dragonRow;
+};

src/dragon-curve/index.spec.js

@@ -1,5 +1,19 @@
-import {dragonCurve} from './index'
+import {dragonCurve} from './index';
 
 describe('dragonCurve::', () => {
-  // need to implement
-});
+  it('Function returns dragon row with curves', () => {
+    expect(dragonCurve(1)).toEqual('1');
+  });
+
+  it('Function returns dragon row with curves', () => {
+    expect(dragonCurve(2)).toEqual('110');
+  });
+
+  it('Function returns dragon row with curves', () => {
+    expect(dragonCurve(3)).toEqual('1101100');
+  });
+
+  it('Function returns dragon row with curves', () => {
+    expect(dragonCurve(4)).toEqual('110110011100100');
+  });
+});

src/rotate-matrix/index.js

@@ -1,4 +1,14 @@
 export const rotateMatrix = arr => {
-  // logic...
-};
+  const resultArray = [];
+  const len = arr.length;
+  let rowArray = [];
 
+  for (let col = 0; col < len; col++){
+    for (let row = 0; row < len; row++){
+      rowArray.push(arr[row][col]);      
+    }
+    resultArray.push(rowArray);
+    rowArray = [];    
+  }  
+  return resultArray;
+};

src/rotate-matrix/index.spec.js

@@ -1,5 +1,61 @@
 import {rotateMatrix} from './index'
 
+expect.extend({
+  compareTwoArrays (received, array) {
+    let pass = true;
+    const len = array.length;
+    for(let row = 0; row < len; row++){
+      for(let col = 0; col < len; col++){
+        if (received[row][col] !== array[row][col]){
+          pass = false;
+        }
+      }         
+    }  
+    if (pass) {
+      return {
+        message: () =>
+          'Test OK',
+        pass: true,
+      };
+    } else {
+      return {
+        message: () =>
+        'Test Fail',
+        pass: false,
+      };
+    }
+  },
+});
+
+const arr1 = [
+  [1, 2],
+  [3, 4]
+];
+
+const arr2 = [
+  [1, 2, 3],
+  [4, 5, 6],
+  [7, 8, 9]
+];
+
+const res1 = [
+  [1, 3],
+  [2, 4]
+];
+
+const res2 = [
+  [1, 4, 7],
+  [2, 5, 8],
+  [3, 6, 9]
+];
+
 describe('rotateMatrix::', () => {
-  // need to implement
+
+  it('That function returns rotated array', () => {
+    expect(rotateMatrix(arr1)).compareTwoArrays(res1);    
+  });
+
+  it('That function returns rotated array', () => {
+    expect(rotateMatrix(arr2)).compareTwoArrays(res2);    
+  });
 });