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>

Data-Structures/Tree/AVLTree.js

@@ -13,9 +13,9 @@
  * RETURN > 0 if a > b
  * MUST RETURN 0 if a == b
  */
-let utils;
-(function (_utils) {
-  function comparator () {
+let utils
+;(function (_utils) {
+  function comparator() {
     return function (v1, v2) {
       if (v1 < v2) return -1
       if (v2 < v1) return 1
@@ -32,7 +32,7 @@ let utils;
  * If no argument is sent it uses utils.comparator
  */
 const AVLTree = (function () {
-  function _avl (comp) {
+  function _avl(comp) {
     /** @public comparator function */
     this._comp = undefined
     this._comp = comp !== undefined ? comp : utils.comparator()
@@ -53,7 +53,9 @@ const AVLTree = (function () {
 
   // get height of a node
   const getHeight = function (node) {
-    if (node == null) { return 0 }
+    if (node == null) {
+      return 0
+    }
     return node._height
   }
 
@@ -64,12 +66,15 @@ const AVLTree = (function () {
 
   // update height of a node based on children's heights
   const updateHeight = function (node) {
-    if (node == null) { return }
+    if (node == null) {
+      return
+    }
     node._height = Math.max(getHeight(node._left), getHeight(node._right)) + 1
   }
 
   // Helper: To check if the balanceFactor is valid
-  const isValidBalanceFactor = (balanceFactor) => [0, 1, -1].includes(balanceFactor)
+  const isValidBalanceFactor = (balanceFactor) =>
+    [0, 1, -1].includes(balanceFactor)
 
   // rotations of AVL Tree
   const leftRotate = function (node) {
@@ -140,13 +145,18 @@ const AVLTree = (function () {
     }
     updateHeight(root)
     const balanceFactor = getHeightDifference(root)
-    return isValidBalanceFactor(balanceFactor) ? root : insertBalance(root, val, balanceFactor, tree)
+    return isValidBalanceFactor(balanceFactor)
+      ? root
+      : insertBalance(root, val, balanceFactor, tree)
   }
 
   // delete am element
   const deleteElement = function (root, _val, tree) {
-    if (root == null) { return root }
-    if (tree._comp(root._val, _val) === 0) { // key found case
+    if (root == null) {
+      return root
+    }
+    if (tree._comp(root._val, _val) === 0) {
+      // key found case
       if (root._left === null && root._right === null) {
         root = null
         tree.size--
@@ -177,7 +187,9 @@ const AVLTree = (function () {
   }
   // search tree for a element
   const searchAVLTree = function (root, val, tree) {
-    if (root == null) { return null }
+    if (root == null) {
+      return null
+    }
     if (tree._comp(root._val, val) === 0) {
       return root
     }
@@ -222,7 +234,7 @@ const AVLTree = (function () {
     return prevSize !== this.size
   }
   return _avl
-}())
+})()
 
 /**
  * A Code for Testing the AVLTree

Data-Structures/Tree/BinarySearchTree.js

@@ -1,19 +1,19 @@
 /* Binary Search Tree!!
-*
-* Nodes that will go on the Binary Tree.
-* They consist of the data in them, the node to the left, the node
-* to the right, and the parent from which they came from.
-*
-* A binary tree is a data structure in which an element
-* has two successors(children). The left child is usually
-* smaller than the parent, and the right child is usually
-* bigger.
-*/
+ *
+ * Nodes that will go on the Binary Tree.
+ * They consist of the data in them, the node to the left, the node
+ * to the right, and the parent from which they came from.
+ *
+ * A binary tree is a data structure in which an element
+ * has two successors(children). The left child is usually
+ * smaller than the parent, and the right child is usually
+ * bigger.
+ */
 
 // class Node
-const Node = (function Node () {
+const Node = (function Node() {
   // Node in the tree
-  function Node (val) {
+  function Node(val) {
     this.value = val
     this.left = null
     this.right = null
@@ -32,7 +32,7 @@ const Node = (function Node () {
   }
 
   // Visit a node
-  Node.prototype.visit = function (output = value => console.log(value)) {
+  Node.prototype.visit = function (output = (value) => console.log(value)) {
     // Recursively go left
     if (this.left !== null) {
       this.left.visit()
@@ -103,14 +103,14 @@ const Node = (function Node () {
   }
   // returns the constructor
   return Node
-}())
+})()
 
 // class Tree
 const Tree = (function () {
-  function Tree () {
+  function Tree() {
     // Just store the root
     this.root = null
-  };
+  }
 
   // Inorder traversal
   Tree.prototype.traverse = function () {
@@ -149,6 +149,6 @@ const Tree = (function () {
 
   // returns the constructor
   return Tree
-}())
+})()
 
 export { Tree }

Data-Structures/Tree/SegmentTree.js

@@ -13,7 +13,7 @@
 class SegmentTree {
   size
   tree
-  constructor (arr) {
+  constructor(arr) {
     // we define tree like this
     // tree[1] : root node of tree
     // tree[i] : i'th node
@@ -28,7 +28,7 @@ class SegmentTree {
   }
 
   // function to build the tree
-  build (arr) {
+  build(arr) {
     const { size, tree } = this
     // insert leaf nodes in tree
     // leaf nodes will start from index N
@@ -45,7 +45,7 @@ class SegmentTree {
     }
   }
 
-  update (index, value) {
+  update(index, value) {
     const { size, tree } = this
 
     // only update values in the parents of the given node being changed.
@@ -65,7 +65,7 @@ class SegmentTree {
   }
 
   // interval [L,R) with left index(L) included and right (R) excluded.
-  query (left, right) {
+  query(left, right) {
     const { size, tree } = this
     // cause R is excluded, increase right for convenient
     right++

Data-Structures/Tree/Trie.js

@@ -1,4 +1,4 @@
-const TrieNode = function TrieNode (key, parent) {
+const TrieNode = function TrieNode(key, parent) {
   this.key = key
   this.count = 0
   this.children = Object.create(null)
@@ -9,7 +9,7 @@ const TrieNode = function TrieNode (key, parent) {
   }
 }
 
-function Trie () {
+function Trie() {
   // create only root with null key and parent
   this.root = new TrieNode(null, null)
 }
@@ -18,7 +18,9 @@ function Trie () {
 Trie.findAllWords = function (root, word, output) {
   if (root === null) return
   if (root.count > 0) {
-    if (typeof output === 'object') { output.push({ word, count: root.count }) }
+    if (typeof output === 'object') {
+      output.push({ word, count: root.count })
+    }
   }
   let key
   for (key in root.children) {
@@ -38,7 +40,9 @@ Trie.prototype.insert = function (word) {
   const len = word.length
   let i
   for (i = 0; i < len; i++) {
-    if (node.children[word.charAt(i)] === undefined) { node.children[word.charAt(i)] = new TrieNode(word.charAt(i), node) }
+    if (node.children[word.charAt(i)] === undefined) {
+      node.children[word.charAt(i)] = new TrieNode(word.charAt(i), node)
+    }
     node = node.children[word.charAt(i)]
   }
   node.count += 1
@@ -87,7 +91,11 @@ Trie.prototype.remove = function (word, count) {
   // if the object forms some other objects prefix we don't delete it
   // For checking an empty object
   // https://stackoverflow.com/questions/679915/how-do-i-test-for-an-empty-javascript-object
-  if (child.count <= 0 && (Object.keys(child.children).length && child.children.constructor === Object)) {
+  if (
+    child.count <= 0 &&
+    Object.keys(child.children).length &&
+    child.children.constructor === Object
+  ) {
     child.parent.children[child.key] = undefined
   }
 }

Data-Structures/Tree/test/AVLTree.test.js

@@ -12,14 +12,14 @@ describe('AVLTree Implementation: ', () => {
   const emptyTree = new AVLTree(collator.compare)
 
   beforeAll(() => {
-    demoData.forEach(item => {
+    demoData.forEach((item) => {
       if (avlTree.add(item)) {
         dataList.push(item)
       }
     })
 
     avlStringTree._comp = collator.compare
-    stringData.forEach(item => avlStringTree.add(item))
+    stringData.forEach((item) => avlStringTree.add(item))
   })
 
   it('delete and search from empty tree', () => {
@@ -33,10 +33,10 @@ describe('AVLTree Implementation: ', () => {
   })
 
   it('search if inserted element is present', () => {
-    demoData.forEach(data => {
+    demoData.forEach((data) => {
       expect(avlTree.find(data)).toBeTruthy()
     })
-    stringData.forEach(data => {
+    stringData.forEach((data) => {
       expect(avlStringTree.find(data)).toBeTruthy()
     })
   })