Add test for camel case algorithm

String/CheckCamelCase.js

@@ -3,18 +3,18 @@
 // Problem Source & Explanation: https://en.wikipedia.org/wiki/Camel_case
 
 /**
- * CheckCamelCase method returns true if the string in camelCase, else return the false.
+ * checkCamelCase method returns true if the string in camelCase, else return the false.
  * @param {String} varName the name of the variable to check.
  * @returns `Boolean` return true if the string is in camelCase, else return false.
  */
-const CheckCamelCase = (varName) => {
+const checkCamelCase = (varName) => {
   // firstly, check that input is a string or not.
   if (typeof varName !== 'string') {
-    return new TypeError('Argument is not a string.')
+    throw new TypeError('Argument is not a string.')
   }
 
   const pat = /^[a-z][A-Za-z]*$/
   return pat.test(varName)
 }
 
-module.exports = CheckCamelCase
+export { checkCamelCase }

String/test/CheckCamelCase.test.js

@@ -0,0 +1,18 @@
+import { checkCamelCase } from '../CheckCamelCase'
+describe('checkCamelCase', () => {
+  it('expect to throw an error if input is not a string', () => {
+    expect(() => checkCamelCase(null)).toThrow()
+  })
+
+  it('expects to return true if the input is in camel case format', () => {
+    const value = 'dockerBuild'
+    const result = checkCamelCase(value)
+    expect(result).toBe(true)
+  })
+
+  it('expects to return false if the input is not in camel case format', () => {
+    const value = 'docker_build'
+    const result = checkCamelCase(value)
+    expect(result).toBe(false)
+  })
+})