Created solution and unit tests for the tasks dragon-curve and rotate-…

babel.config.js

@@ -0,0 +1,3 @@
+module.exports = {
+  presets: ['@babel/preset-env'],
+};

package.json

@@ -30,6 +30,10 @@
     "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 +1,28 @@
 export const dragonCurve = n => {
-  // logic...
-};
+  let curve = '1';
+  let counter = n;
+
+  function getDragonCurve () {
+    if (counter > 1) {
+      counter--;
+
+      const str = getDragonCurve(n - 1);
+      curve += `1${flipAndReverse(str)}`;
+    }
+
+    return curve;
+  }
+
+  function flipAndReverse (str) {
+    if (str) {
+
+      return str
+        .split('')
+        .map(value => parseInt(value, 10) === 1 ? 0 : 1)
+        .reverse()
+        .join('');
+    }
+  }
+
+  return getDragonCurve();
+};

src/dragon-curve/index.spec.js

@@ -1,5 +1,23 @@
-import {dragonCurve} from './index'
+import {dragonCurve} from './index';
 
 describe('dragonCurve::', () => {
-  // need to implement
+  it('Shoult return a dragon curve for the number 1', () => {
+    expect(dragonCurve(1)).toBe('1');
+  });
+
+  it('Shoult return a dragon curve for the number 2', () => {
+    expect(dragonCurve(2)).toBe('110');
+  });
+
+  it('Shoult return a dragon curve for the number 3', () => {
+    expect(dragonCurve(3)).toBe('1101100');
+  });
+
+  it('Shoult return a dragon curve for the number 4', () => {
+    expect(dragonCurve(4)).toBe('110110011100100');
+  });
+
+  it('Shoult return a dragon curve for the number 5', () => {
+    expect(dragonCurve(5)).toBe('1101100111001001110110001100100');
+  });
 });

src/rotate-matrix/index.js

@@ -1,4 +1,11 @@
 export const rotateMatrix = arr => {
-  // logic...
-};
+  const resultArr = arr.map(() => []);
+
+  arr.forEach(outerItem => {
+    outerItem.forEach((innerItem, innerIndex) => {
+      resultArr[innerIndex].push(innerItem);
+    });
+  });
 
+  return resultArr;
+};

src/rotate-matrix/index.spec.js

@@ -1,5 +1,39 @@
-import {rotateMatrix} from './index'
+import {rotateMatrix} from './index';
 
 describe('rotateMatrix::', () => {
-  // need to implement
+  it('Should transform an array 2x2 by replacing its values', () => {
+    expect(rotateMatrix([
+      [1, 2],
+      [3, 4] ]
+    )).toEqual([
+      [1, 3],
+      [2, 4] 
+    ]);
+  });
+
+  it('Should transform an array 3x3 by replacing its values', () => {
+    expect(rotateMatrix([
+      [1,2,3],
+      [4,5,6],
+      [7,8,9]
+    ])).toEqual([
+      [1,4,7],
+      [2,5,8],
+      [3,6,9]
+    ]);
+  });
+
+  it('Should transform an array 4x4 by replacing its values', () => {
+    expect(rotateMatrix([
+      [1,2,3,4],
+      [5,6,7,8],
+      [9,10,11,12],
+      [13,14,15,16]
+    ])).toEqual([
+      [1,5,9,13],
+      [2,6,10,14],
+      [3,7,11,15],
+      [4,8,12,16]
+    ]);
+  });
 });