feat(sprint-3): implement count function with TDD

Author: Tarawally

Sprint-3/2-practice-tdd/count.js

@@ -1,5 +1,9 @@
 function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  let count = 0;
+  for (let i = 0; i < stringOfCharacters.length; i++) {
+    if (stringOfCharacters[i] === findCharacter) count++;
+  }
+  return count;
 }
 
 module.exports = countChar;

Sprint-3/2-practice-tdd/count.test.js

@@ -1,24 +1,25 @@
-// implement a function countChar that counts the number of times a character occurs in a string
 const countChar = require("./count");
-// Given a string str and a single character char to search for,
-// When the countChar function is called with these inputs,
-// Then it should:
-
-// Scenario: Multiple Occurrences
-// Given the input string str,
-// And a character char that may occur multiple times with overlaps within str (e.g., 'a' in 'aaaaa'),
-// When the function is called with these inputs,
-// Then it should correctly count overlapping occurrences of char (e.g., 'a' appears five times in 'aaaaa').
 
 test("should count multiple occurrences of a character", () => {
-  const str = "aaaaa";
-  const char = "a";
-  const count = countChar(str, char);
-  expect(count).toEqual(5);
+  expect(countChar("aaaaa", "a")).toEqual(5);
+});
+
+test("should return 0 when character is not found", () => {
+  expect(countChar("hello", "z")).toEqual(0);
+});
+
+test("should count a single occurrence of a character", () => {
+  expect(countChar("hello", "h")).toEqual(1);
 });
 
-// Scenario: No Occurrences
-// Given the input string str,
-// And a character char that does not exist within the case-sensitive str,
-// When the function is called with these inputs,
-// Then it should return 0, indicating that no occurrences of the char were found in the case-sensitive str.
+test("should be case-sensitive", () => {
+  expect(countChar("Hello", "h")).toEqual(0);
+});
+
+test("should count uppercase characters separately", () => {
+  expect(countChar("Hello", "H")).toEqual(1);
+});
+
+test("should count character occurring multiple times in different positions", () => {
+  expect(countChar("banana", "a")).toEqual(3);
+});