feat: Test running overhaul, switch to Prettier & reformat everything (#1407)

* chore: Switch to Node 20 + Vitest

* chore: migrate to vitest mock functions

* chore: code style (switch to prettier)

* test: re-enable long-running test

Seems the switch to Node 20 and Vitest has vastly improved the code's and / or the test's runtime!

see #1193

* chore: code style

* chore: fix failing tests

* Updated Documentation in README.md

* Update contribution guidelines to state usage of Prettier

* fix: set prettier printWidth back to 80

* chore: apply updated code style automatically

* fix: set prettier line endings to lf again

* chore: apply updated code style automatically

---------

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Co-authored-by: Lars Müller <34514239+appgurueu@users.noreply.github.com>

Trees/BreadthFirstTreeTraversal.js

@@ -4,7 +4,7 @@
 */
 
 class Node {
-  constructor (data) {
+  constructor(data) {
     this.data = data
     this.left = null
     this.right = null
@@ -12,11 +12,11 @@ class Node {
 }
 
 class BinaryTree {
-  constructor () {
+  constructor() {
     this.root = null
   }
 
-  breadthFirstIterative () {
+  breadthFirstIterative() {
     const traversal = []
     if (this.root) {
       traversal.push(this.root)
@@ -34,7 +34,7 @@ class BinaryTree {
     return traversal
   }
 
-  breadthFirstRecursive () {
+  breadthFirstRecursive() {
     const traversal = []
     const h = this.getHeight(this.root)
     for (let i = 0; i !== h; i++) {
@@ -44,7 +44,7 @@ class BinaryTree {
   }
 
   // Computing the height of the tree
-  getHeight (node) {
+  getHeight(node) {
     if (node === null) {
       return 0
     }
@@ -53,7 +53,7 @@ class BinaryTree {
     return lheight > rheight ? lheight + 1 : rheight + 1
   }
 
-  traverseLevel (node, levelRemaining, traversal) {
+  traverseLevel(node, levelRemaining, traversal) {
     if (node === null) {
       return
     }

Trees/DepthFirstSearch.js

@@ -2,10 +2,10 @@
  * Author: Surendra Kumar
  * DFS Algorithm implementation in JavaScript
  * DFS Algorithm for traversing or searching graph data structures.
-*/
+ */
 
 // traverses a give tree from specified root's value
-function traverseDFS (tree, rootValue) {
+function traverseDFS(tree, rootValue) {
   const stack = []
   const res = []
   stack.push(searchDFS(tree, rootValue))
@@ -24,7 +24,7 @@ function traverseDFS (tree, rootValue) {
   return res.reverse()
 }
 
-function searchDFS (tree, value) {
+function searchDFS(tree, value) {
   const stack = []
   stack.push(tree[0])
   while (stack.length !== 0) {

Trees/FenwickTree.js

@@ -2,10 +2,10 @@
  * Author: Mohit Kumar
  * Fenwick Tree Implementation in JavaScript
  * Fenwick Tree Implementation for finding prefix sum.
-*/
+ */
 
 class FenwickTree {
-  constructor (feneickArray, array, n) {
+  constructor(feneickArray, array, n) {
     for (let i = 1; i <= n; i++) {
       feneickArray[i] = 0
     }
@@ -14,20 +14,20 @@ class FenwickTree {
     }
   }
 
-  update (feneickArray, n, index, value) {
+  update(feneickArray, n, index, value) {
     index = index + 1
     while (index <= n) {
       feneickArray[index] += value
-      index += index & (-index)
+      index += index & -index
     }
   }
 
-  getPrefixSum (feneickArray, index) {
+  getPrefixSum(feneickArray, index) {
     let currSum = 0
     index = index + 1
     while (index > 0) {
       currSum += feneickArray[index]
-      index -= index & (-index)
+      index -= index & -index
     }
 
     return currSum