diff --git a/String/CheckVowels.test.js b/String/CheckVowels.test.js
index fd074e924..fe002a8c1 100644
--- a/String/CheckVowels.test.js
+++ b/String/CheckVowels.test.js
@@ -4,9 +4,64 @@ describe('Test the checkVowels function', () => {
   it('expect throws on use wrong param', () => {
     expect(() => checkVowels(0)).toThrow()
   })
+
   it('count the vowels in a string', () => {
     const value = 'Mad World'
     const countVowels = checkVowels(value)
     expect(countVowels).toBe(2)
   })
+
+  it('should return 0 when input is a string with no vowels', () => {
+    const value = 'bcdfgh'
+    const countVowels = checkVowels(value)
+    expect(countVowels).toBe(0)
+  })
+
+  it('should return 1 when input is a string of length 1 that is a vowel', () => {
+    const value = 'a'
+    const countVowels = checkVowels(value)
+    expect(countVowels).toBe(1)
+  })
+
+  it('should return the correct result when input is in all uppercase letters', () => {
+    const value = 'ABCDE'
+    const countVowels = checkVowels(value)
+    expect(countVowels).toBe(2)
+  })
+
+  it('should return the correct result when input is in all lowercase letters', () => {
+    const value = 'abcdefghi'
+    const countVowels = checkVowels(value)
+    expect(countVowels).toBe(3)
+  })
+
+  it('should return the correct result when input string contains spaces', () => {
+    const value = 'abc def   ghi'
+    const countVowels = checkVowels(value)
+    expect(countVowels).toBe(3)
+  })
+
+  it('should return the correct result when input contains number characters', () => {
+    const value = 'a1b2c3'
+    const countVowels = checkVowels(value)
+    expect(countVowels).toBe(1)
+  })
+
+  it('should return the correct result when input contains punctuation characters', () => {
+    const value = 'a!b.ce)'
+    const countVowels = checkVowels(value)
+    expect(countVowels).toBe(2)
+  })
+
+  it('should return 0 when the input is an empty string', () => {
+    const value = ''
+    const countVowels = checkVowels(value)
+    expect(countVowels).toBe(0)
+  })
+
+  it('should count multiple occurances of the same vowel in the input', () => {
+    const value = 'aaaaa'
+    const countVowels = checkVowels(value)
+    expect(countVowels).toBe(5)
+  })
 })