Added test for ScrambleStrings and formatted folder structure for other folders

String/test/CheckWordOcurrence.test.js

@@ -0,0 +1,33 @@
+import { checkWordOccurrence } from '../CheckWordOccurrence'
+describe('checkWordOccurrence', () => {
+  it('expects throw on insert wrong string', () => {
+    const value = 123
+    expect(() => checkWordOccurrence(value)).toThrow()
+  })
+  it('expect throw on insert wrong param for case sensitive', () => {
+    const value = 'hello'
+    expect(() => checkWordOccurrence(value, value)).toThrow()
+  })
+  it('check occurrence with case sensitive', () => {
+    const stringToTest = 'A Mad World'
+    const charsOccurrences = checkWordOccurrence(stringToTest, true)
+    const expectResult = { A: 1, M: 1, a: 1, d: 2, W: 1, l: 1, o: 1, r: 1 }
+    const occurrencesObjectKeys = Object.keys(charsOccurrences)
+    const expectObjectKeys = Object.keys(expectResult)
+    expect(occurrencesObjectKeys.length).toBe(expectObjectKeys.length)
+    expectObjectKeys.forEach(key => {
+      expect(expectResult[key]).toBe(charsOccurrences[key])
+    })
+  })
+  it('check occurrence with case insensitive', () => {
+    const stringToTest = 'A Mad World'
+    const charsOccurrences = checkWordOccurrence(stringToTest, false)
+    const expectResult = { A: 2, D: 2, L: 1, M: 1, O: 1, R: 1, W: 1 }
+    const occurrencesObjectKeys = Object.keys(charsOccurrences)
+    const expectObjectKeys = Object.keys(expectResult)
+    expect(occurrencesObjectKeys.length).toBe(expectObjectKeys.length)
+    expectObjectKeys.forEach(key => {
+      expect(expectResult[key]).toBe(charsOccurrences[key])
+    })
+  })
+})