test: add cases for no occurrences and case sensitivity in countChar function

Author: Grajales-K

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

@@ -4,21 +4,41 @@ const countChar = require("./count");
 // When the countChar function is called with these inputs,
 // Then it should:
 
+// Scenario: No Occurrences
+// Given the input string `str`,
+// And a character `char` that does not exist within `str`.
+// When the function is called with these inputs,
+// Then it should return 0, indicating that no occurrences of `char` were found.
+test("should return no occurrences if no found character", () => {
+    const str = "jhhfdd";
+    const char = "r";
+    const count = countChar(str, char);
+    expect(count).toEqual(0);
+  });
+
 // Scenario: Multiple Occurrences
 // Given the input string `str`,
 // And a character `char` that occurs one or more times in `str` (e.g., 'a' in 'aaaaa'),
 // When the function is called with these inputs,
 // Then it should correctly count occurrences of `char`.
-
 test("should count multiple occurrences of a character", () => {
   const str = "aaaaa";
   const char = "a";
   const count = countChar(str, char);
   expect(count).toEqual(5);
 });
 
-// Scenario: No Occurrences
-// Given the input string `str`,
-// And a character `char` that does not exist within `str`.
-// When the function is called with these inputs,
-// Then it should return 0, indicating that no occurrences of `char` were found.
+// case 2
+test("should return 1 when the character appears only once", () => {
+  expect(countChar("hello", "h")).toEqual(1);
+});
+
+// case 3
+test("Should return 0 for empty string", () => {
+  expect(countChar("", "a")).toEqual(0)
+}) 
+
+// case 4
+test("should be case sensitive", () => {
+  expect(countChar("aA", "a")).toEqual(1);
+});