merge: Add CheckExceeding function (#907)

* feat: add checkExceeding function

* test: add test cases of checkExceeding func

* test: add more not increasing words

String/CheckExceeding.js

@@ -0,0 +1,42 @@
+/**
+ * @function checkExceeding
+ * @description - Exceeding words are words where the gap between two adjacent characters is increasing. The gap is the distance in ascii
+ * @param {string} str
+ * @returns {boolean}
+ * @example - checkExceeding('delete') => true, ascii difference - [1, 7, 7, 15, 15] which is incremental
+ * @example - checkExceeding('update') => false, ascii difference - [5, 12, 3, 19, 15] which is not incremental
+ */
+const checkExceeding = (str) => {
+  if (typeof str !== 'string') {
+    throw new TypeError('Argument is not a string')
+  }
+
+  const upperChars = str
+    .toUpperCase()
+    .replace(/[^A-Z]/g, '') // remove all from str except A to Z alphabets
+
+  const adjacentDiffList = []
+
+  for (let i = 0; i < upperChars.length - 1; i++) {
+    // destructuring current char & adjacent char by index, cause in javascript String is an object.
+    const { [i]: char, [i + 1]: adjacentChar } = upperChars
+
+    if (char !== adjacentChar) {
+      adjacentDiffList.push(
+        Math.abs(char.charCodeAt() - adjacentChar.charCodeAt())
+      )
+    }
+  }
+
+  for (let i = 0; i < adjacentDiffList.length - 1; i++) {
+    const { [i]: charDiff, [i + 1]: secondCharDiff } = adjacentDiffList
+
+    if (charDiff > secondCharDiff) {
+      return false
+    }
+  }
+
+  return true
+}
+
+export { checkExceeding }

String/test/CheckExceeding.test.js

@@ -0,0 +1,46 @@
+import { checkExceeding } from '../CheckExceeding'
+
+describe('Testing CheckExceeding function', () => {
+  it('Testing the invalid types', () => {
+    expect(() => checkExceeding(Math.random())).toThrow('Argument is not a string')
+    expect(() => checkExceeding(null)).toThrow('Argument is not a string')
+    expect(() => checkExceeding(false)).toThrow('Argument is not a string')
+    expect(() => checkExceeding(false)).toThrow('Argument is not a string')
+  })
+
+  it('Testing with empty string', () => {
+    expect(checkExceeding('')).toBe(true)
+  })
+
+  it('Testing with linear alphabets', () => {
+    expect(checkExceeding('a b c d e ')).toBe(true)
+    expect(checkExceeding('f g h i j ')).toBe(true)
+    expect(checkExceeding('k l m n o ')).toBe(true)
+    expect(checkExceeding('p q r s t ')).toBe(true)
+    expect(checkExceeding('u v w x y z')).toBe(true)
+  })
+
+  it('Testing not exceeding words', () => {
+    expect(checkExceeding('Hello')).toBe(false)
+    expect(checkExceeding('world')).toBe(false)
+    expect(checkExceeding('update')).toBe(false)
+    expect(checkExceeding('university')).toBe(false)
+    expect(checkExceeding('dog')).toBe(false)
+    expect(checkExceeding('exceeding')).toBe(false)
+    expect(checkExceeding('resolved')).toBe(false)
+    expect(checkExceeding('future')).toBe(false)
+    expect(checkExceeding('fixed')).toBe(false)
+    expect(checkExceeding('codes')).toBe(false)
+    expect(checkExceeding('facebook')).toBe(false)
+    expect(checkExceeding('vscode')).toBe(false)
+  })
+
+  it('Testing exceeding words', () => {
+    expect(checkExceeding('bee')).toBe(true) // [ 3 ]
+    expect(checkExceeding('can')).toBe(true) // [ 2, 13 ]
+    expect(checkExceeding('good')).toBe(true) //  [ 8, 11 ]
+    expect(checkExceeding('bad')).toBe(true) // [ 1, 3 ]
+    expect(checkExceeding('play')).toBe(true) // [ 4, 11, 24 ]
+    expect(checkExceeding('delete')).toBe(true) // [1, 7, 7, 15, 15]
+  })
+})