Upgrade packages.

package.json

@@ -36,17 +36,17 @@
   },
   "homepage": "https://github.com/trekhleb/javascript-algorithms#readme",
   "devDependencies": {
-    "@types/jest": "^22.2.3",
+    "@types/jest": "^23.1.4",
     "babel-cli": "^6.26.0",
     "babel-preset-env": "^1.7.0",
     "codecov": "^3.0.2",
     "eslint": "^4.19.1",
-    "eslint-config-airbnb": "^16.1.0",
-    "eslint-plugin-import": "^2.12.0",
-    "eslint-plugin-jest": "^21.15.2",
-    "eslint-plugin-jsx-a11y": "^6.0.3",
-    "eslint-plugin-react": "^7.8.2",
-    "jest": "^22.4.4",
+    "eslint-config-airbnb": "^17.0.0",
+    "eslint-plugin-import": "^2.13.0",
+    "eslint-plugin-jest": "^21.17.0",
+    "eslint-plugin-jsx-a11y": "^6.1.0",
+    "eslint-plugin-react": "^7.10.0",
+    "jest": "^23.3.0",
     "pre-commit": "^1.2.2"
   },
   "dependencies": {}

src/algorithms/graph/prim/prim.js

@@ -60,8 +60,8 @@ export default function prim(graph) {
       nextMinVertex.getEdges().forEach((graphEdge) => {
         // Add only vertices that link to unvisited nodes.
         if (
-          !visitedVertices[graphEdge.startVertex.getKey()] ||
-          !visitedVertices[graphEdge.endVertex.getKey()]
+          !visitedVertices[graphEdge.startVertex.getKey()]
+          || !visitedVertices[graphEdge.endVertex.getKey()]
         ) {
           edgesQueue.add(graphEdge, graphEdge.weight);
         }

src/algorithms/math/primality-test/trialDivision.js

@@ -11,7 +11,9 @@ export default function trialDivision(number) {
   if (number <= 1) {
     // If number is less than one then it isn't prime by definition.
     return false;
-  } else if (number <= 3) {
+  }
+
+  if (number <= 3) {
     // All numbers from 2 to 3 are prime.
     return true;
   }

src/algorithms/sets/knapsack-problem/Knapsack.js

@@ -128,16 +128,16 @@ export default class Knapsack {
       // In this case this would mean that we need to include previous item
       // to the list of selected items.
       if (
-        knapsackMatrix[itemIndex][weightIndex] &&
-        knapsackMatrix[itemIndex][weightIndex] === knapsackMatrix[itemIndex - 1][weightIndex]
+        knapsackMatrix[itemIndex][weightIndex]
+        && knapsackMatrix[itemIndex][weightIndex] === knapsackMatrix[itemIndex - 1][weightIndex]
       ) {
         // Check if there are several items with the same weight but with the different values.
         // We need to add highest item in the matrix that is possible to get the highest value.
         const prevSumValue = knapsackMatrix[itemIndex - 1][weightIndex];
         const prevPrevSumValue = knapsackMatrix[itemIndex - 2][weightIndex];
         if (
-          !prevSumValue ||
-          (prevSumValue && prevPrevSumValue !== prevSumValue)
+          !prevSumValue
+          || (prevSumValue && prevPrevSumValue !== prevSumValue)
         ) {
           this.selectedItems.push(prevItem);
         }

src/algorithms/sorting/insertion-sort/InsertionSort.js

@@ -14,8 +14,8 @@ export default class InsertionSort extends Sort {
       // Go and check if previous elements and greater then current one.
       // If this is the case then swap that elements.
       while (
-        array[currentIndex - 1] !== undefined &&
-        this.comparator.lessThan(array[currentIndex], array[currentIndex - 1])
+        array[currentIndex - 1] !== undefined
+        && this.comparator.lessThan(array[currentIndex], array[currentIndex - 1])
       ) {
         // Call visiting callback.
         this.callbacks.visitingCallback(array[currentIndex - 1]);

src/algorithms/sorting/radix-sort/RadixSort.js

@@ -18,9 +18,9 @@ export default class RadixSort extends Sort {
     const numPasses = this.determineNumPasses(sortedArray);
 
     for (let currentIndex = 0; currentIndex < numPasses; currentIndex += 1) {
-      const buckets = isArrayOfNumbers ?
-        this.placeElementsInNumberBuckets(sortedArray, currentIndex) :
-        this.placeElementsInCharacterBuckets(sortedArray, currentIndex, numPasses);
+      const buckets = isArrayOfNumbers
+        ? this.placeElementsInNumberBuckets(sortedArray, currentIndex)
+        : this.placeElementsInCharacterBuckets(sortedArray, currentIndex, numPasses);
 
       // Flatten buckets into sortedArray, and repeat at next index
       sortedArray = buckets.reduce((acc, val) => {

src/algorithms/string/regular-expression-matching/regularExpressionMatching.js

@@ -88,18 +88,18 @@ export default function regularExpressionMatching(string, pattern) {
           matchMatrix[rowIndex][columnIndex] = true;
         } else if (
           (
-            pattern[patternIndex - 1] === string[stringIndex] ||
-            pattern[patternIndex - 1] === ANY_CHAR
-          ) &&
-          matchMatrix[rowIndex - 1][columnIndex] === true
+            pattern[patternIndex - 1] === string[stringIndex]
+            || pattern[patternIndex - 1] === ANY_CHAR
+          )
+          && matchMatrix[rowIndex - 1][columnIndex] === true
         ) {
           matchMatrix[rowIndex][columnIndex] = true;
         } else {
           matchMatrix[rowIndex][columnIndex] = false;
         }
       } else if (
-        pattern[patternIndex] === string[stringIndex] ||
-        pattern[patternIndex] === ANY_CHAR
+        pattern[patternIndex] === string[stringIndex]
+        || pattern[patternIndex] === ANY_CHAR
       ) {
         /*
          * In case if current pattern char is the same as current string char

src/algorithms/string/z-algorithm/zAlgorithm.js

@@ -40,8 +40,8 @@ function buildZArray(zString) {
       // more characters that are equal to the ones in the prefix we will expand
       // right Z box boundary by 3.
       while (
-        zBoxRightIndex < zString.length &&
-        zString[zBoxRightIndex - zBoxLeftIndex] === zString[zBoxRightIndex]
+        zBoxRightIndex < zString.length
+        && zString[zBoxRightIndex - zBoxLeftIndex] === zString[zBoxRightIndex]
       ) {
         // Expanding Z box right boundary.
         zBoxRightIndex += 1;
@@ -81,8 +81,8 @@ function buildZArray(zString) {
         // And start comparing characters one by one as we normally do for the case
         // when we are outside of checkbox.
         while (
-          zBoxRightIndex < zString.length &&
-          zString[zBoxRightIndex - zBoxLeftIndex] === zString[zBoxRightIndex]
+          zBoxRightIndex < zString.length
+          && zString[zBoxRightIndex - zBoxLeftIndex] === zString[zBoxRightIndex]
         ) {
           zBoxRightIndex += 1;
         }

src/algorithms/uncategorized/n-queens/nQueens.js

@@ -16,16 +16,16 @@ function isSafe(queensPositions, rowIndex, columnIndex) {
 
     if (
       // Check if queen has been already placed.
-      currentQueenPosition &&
-      (
+      currentQueenPosition
+      && (
         // Check if there are any queen on the same column.
-        newQueenPosition.columnIndex === currentQueenPosition.columnIndex ||
+        newQueenPosition.columnIndex === currentQueenPosition.columnIndex
         // Check if there are any queen on the same row.
-        newQueenPosition.rowIndex === currentQueenPosition.rowIndex ||
+        || newQueenPosition.rowIndex === currentQueenPosition.rowIndex
         // Check if there are any queen on the same left diagonal.
-        newQueenPosition.leftDiagonal === currentQueenPosition.leftDiagonal ||
+        || newQueenPosition.leftDiagonal === currentQueenPosition.leftDiagonal
         // Check if there are any queen on the same right diagonal.
-        newQueenPosition.rightDiagonal === currentQueenPosition.rightDiagonal
+        || newQueenPosition.rightDiagonal === currentQueenPosition.rightDiagonal
       )
     ) {
       // Can't place queen into current position since there are other queens that

src/data-structures/doubly-linked-list/DoublyLinkedList.js

@@ -1,5 +1,5 @@
 import DoublyLinkedListNode from './DoublyLinkedListNode';
-import Comparator from './../../utils/comparator/Comparator';
+import Comparator from '../../utils/comparator/Comparator';
 
 export default class DoublyLinkedList {
   /**

src/data-structures/doubly-linked-list/__test__/DoublyLinkedListNode.test.js

@@ -1,4 +1,4 @@
-import DoublyLinkedListNode from './../DoublyLinkedListNode';
+import DoublyLinkedListNode from '../DoublyLinkedListNode';
 
 describe('DoublyLinkedListNode', () => {
   it('should create list node with value', () => {

src/data-structures/heap/MinHeap.js

@@ -164,10 +164,10 @@ export default class MinHeap {
         // If there is no parent or parent is less then node to delete then heapify down.
         // Otherwise heapify up.
         if (
-          leftChild !== null &&
-          (
-            parentItem === null ||
-            this.compare.lessThan(parentItem, this.heapContainer[indexToRemove])
+          leftChild !== null
+          && (
+            parentItem === null
+            || this.compare.lessThan(parentItem, this.heapContainer[indexToRemove])
           )
         ) {
           this.heapifyDown(indexToRemove);
@@ -208,8 +208,8 @@ export default class MinHeap {
     let currentIndex = customStartIndex || this.heapContainer.length - 1;
 
     while (
-      this.hasParent(currentIndex) &&
-      this.compare.lessThan(this.heapContainer[currentIndex], this.parent(currentIndex))
+      this.hasParent(currentIndex)
+      && this.compare.lessThan(this.heapContainer[currentIndex], this.parent(currentIndex))
     ) {
       this.swap(currentIndex, this.getParentIndex(currentIndex));
       currentIndex = this.getParentIndex(currentIndex);
@@ -227,8 +227,8 @@ export default class MinHeap {
 
     while (this.hasLeftChild(currentIndex)) {
       if (
-        this.hasRightChild(currentIndex) &&
-        this.compare.lessThan(this.rightChild(currentIndex), this.leftChild(currentIndex))
+        this.hasRightChild(currentIndex)
+        && this.compare.lessThan(this.rightChild(currentIndex), this.leftChild(currentIndex))
       ) {
         nextIndex = this.getRightChildIndex(currentIndex);
       } else {

src/data-structures/tree/binary-search-tree/BinarySearchTreeNode.js

@@ -35,7 +35,9 @@ export default class BinarySearchTreeNode extends BinaryTreeNode {
       this.setLeft(newNode);
 
       return newNode;
-    } else if (this.nodeValueComparator.greaterThan(value, this.value)) {
+    }
+
+    if (this.nodeValueComparator.greaterThan(value, this.value)) {
       // Insert to the right.
       if (this.right) {
         return this.right.insert(value);
@@ -63,7 +65,9 @@ export default class BinarySearchTreeNode extends BinaryTreeNode {
     if (this.nodeValueComparator.lessThan(value, this.value) && this.left) {
       // Check left nodes.
       return this.left.find(value);
-    } else if (this.nodeValueComparator.greaterThan(value, this.value) && this.right) {
+    }
+
+    if (this.nodeValueComparator.greaterThan(value, this.value) && this.right) {
       // Check right nodes.
       return this.right.find(value);
     }