implement countChar function and associated tests

Author: i786m

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

@@ -1,5 +1,8 @@
 function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  return stringOfCharacters.split("").reduce((count, char) => {
+    if (char === findCharacter) count++;
+    return count;
+  }, 0);
 }
 
 module.exports = countChar;

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

@@ -22,3 +22,34 @@ test("should count multiple occurrences of a character", () => {
 // 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 return  0 if no occurrences of a character", () => {
+  const str = "bbbbbb";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+
+// Scenario: Single Occurrence
+test("should return 1 for a single occurrence of a character", () => {
+  const str = "hello";
+  const char = "e";
+  const count = countChar(str, char);
+  expect(count).toEqual(1);
+});
+
+// Scenario: Case Sensitivity
+test("should be case sensitive when counting characters", () => {
+  const str = "Hello World";
+  const char = "h";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+
+// Scenario: Empty String
+test("should return 0 when the input string is empty", () => {
+  const str = "";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+