Merge pull request #735 from charliejmoore/title-case-conversion-tests

Title case conversion tests

Conversions/TitleCaseConversion.js

@@ -1,19 +1,23 @@
 /*
-    Problem statement and Explanation : https://www.codeproject.com/Tips/162540/Letter-Case-Conversion-Algorithms-Title-Case-Toggl
+    Problem statement and Explanation : https://www.codeproject.com/Tips/162540/Letter-Case-Conversion-Algorithms-Title-Case-Toggl.
+    [Title case](https://en.wikipedia.org/wiki/Title_case) is a style where all words are capitalized. Officially, title case
+    does not capitalize some words, such as very short words like "a" or "is", but for the purposes of this function, a general approach
+    is taken where all words are capitalized regarless of length.
 */
 
 /**
- * The TitleCaseConversion converts a string into a title case string.
+ * The titleCaseConversion function converts a string into a title case string.
- * @param {String} inputString input string
+ * @param {string} inputString The input string which can have any types of letter casing.
- * @returns {String}
+ * @returns {string} A string that is in title case.
  */
-const TitleCaseConversion = (inputString) => {
+const titleCaseConversion = (inputString) => {
+  if (inputString === '') return ''
   // Extact all space seprated string.
   const stringCollections = inputString.split(' ').map(word => {
     let firstChar = ''
-    // Get a character code by the use charCodeAt method.
+    // Get the [ASCII](https://en.wikipedia.org/wiki/ASCII) character code by the use charCodeAt method.
     const firstCharCode = word[0].charCodeAt()
-    // If the character code lies between 97 to 122 it means they are in the lower case so convert it.
+    // If the ASCII character code lies between 97 to 122 it means they are in the lowercase so convert it.
     if (firstCharCode >= 97 && firstCharCode <= 122) {
       // Convert the case by use of the above explanation.
       firstChar += String.fromCharCode(firstCharCode - 32)
@@ -22,9 +26,9 @@ const TitleCaseConversion = (inputString) => {
       firstChar += word[0]
     }
     const newWordChar = word.slice(1).split('').map(char => {
-      // Get a character code by the use charCodeAt method.
+      // Get the ASCII character code by the use charCodeAt method.
       const presentCharCode = char.charCodeAt()
-      // If the character code lies between 65 to 90 it means they are in the upper case so convert it.
+      // If the ASCII character code lies between 65 to 90, it means they are in the uppercase so convert it.
       if (presentCharCode >= 65 && presentCharCode <= 90) {
         // Convert the case by use of the above explanation.
         return String.fromCharCode(presentCharCode + 32)
@@ -32,11 +36,11 @@ const TitleCaseConversion = (inputString) => {
       // Else return the characters without any modification.
       return char
     })
-    // return the first converted character and remaining character string.
+    // Return the first converted character and remaining character string.
     return firstChar + newWordChar.join('')
   })
-  // convert all words in a string and return it.
+  // Convert all words in a string and return it.
   return stringCollections.join(' ')
 }
 
-module.exports = TitleCaseConversion
+export { titleCaseConversion }

Conversions/test/TitleCaseConversion.test.js

@@ -0,0 +1,51 @@
+import { titleCaseConversion } from '../TitleCaseConversion'
+
+describe(('Tests for the titleCaseConversion function'), () => {
+  it('should return an empty string when the input is an empty string', () => {
+    expect(titleCaseConversion('')).toEqual('')
+  })
+
+  it('should return the input string when the input string is a title case string', () => {
+    expect(titleCaseConversion('A Proper Title Case String')).toEqual('A Proper Title Case String')
+  })
+
+  it('should return a title case string when input is an all-uppercase string', () => {
+    expect(titleCaseConversion('ALL UPPER CASE')).toEqual('All Upper Case')
+  })
+
+  it('should return a title case string when input is a title case string of with spaces', () => {
+    expect(titleCaseConversion('ALL UPPERCASE')).toEqual('All Uppercase')
+  })
+
+  it('should return a title case string when input is a title case string of with no spaces', () => {
+    expect(titleCaseConversion('ALLUPPERCASE')).toEqual('Alluppercase')
+  })
+
+  it('should return a title case string when input is a title case string with punctuation', () => {
+    expect(titleCaseConversion('All Title Case!')).toEqual('All Title Case!')
+  })
+
+  it('should return a title case string when input is an all-lowercase string with no spaces', () => {
+    expect(titleCaseConversion('lowercaseinput')).toEqual('Lowercaseinput')
+  })
+
+  it('should return a title case string when input is an all-lowercase string with spaces', () => {
+    expect(titleCaseConversion('lowercase input')).toEqual('Lowercase Input')
+  })
+
+  it('should return a title case string when input is an all-lowercase string with punctuation', () => {
+    expect(titleCaseConversion('lower, case, input.')).toEqual('Lower, Case, Input.')
+  })
+
+  it('should return a title case string when input is an mixed-case string', () => {
+    expect(titleCaseConversion('mixeD CaSe INPuT')).toEqual('Mixed Case Input')
+  })
+
+  it('should return a title case string when input is an mixed-case string with no spaces', () => {
+    expect(titleCaseConversion('mixeDCaSeINPuT')).toEqual('Mixedcaseinput')
+  })
+
+  it('should return a title case string when input is an mixed-case string with punctuation', () => {
+    expect(titleCaseConversion('mixeD, CaSe, INPuT!')).toEqual('Mixed, Case, Input!')
+  })
+})