count.test.js

// 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 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.
test( "should return count of zero occurrences of a character", () =>{
   expect(countChar("go home and study","c")).toEqual(0);
});

// Scenario: Case-sensitive matching
// Given a string containing both uppercase and lowercase versions of a letter,
// When the function is called with a lowercase character,
// Then it should only count the lowercase occurrences.

test("should treat character matching as case-sensitive", () => {
 expect(countChar("AaAa","A")).toEqual(2);
});

// Scenario: Non-alphabet characters
// Given a string containing digits and symbols,
// When the function is called with a non-alphabet character,
// Then it should correctly count occurrences of that character.

test("should count occurrences of non-alphabet characters", () => {
  expect(countChar("1-2-3-1-1","1")).toEqual(3);
});