Complete Sprint 3 Practice TDD

Author: fatimarouchi

practice-tdd/count.js

@@ -1,3 +1,3 @@
 export function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  return stringOfCharacters.split(findCharacter).length - 1;
 }

practice-tdd/count.test.js

@@ -1,24 +1,57 @@
 // implement a function countChar that counts the number of times a character occurs in a string
 import { countChar } from "./count.js";
-// 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`.
-
+// Given a string `str` and a character `char` that appears several times,
+// When the function is called,
+// Then it should correctly count each occurrence.
 test("should count multiple occurrences of a character", () => {
   const str = "aaaaa";
   const char = "a";
   const count = countChar(str, char);
   expect(count).toEqual(5);
 });
 
+// Scenario: Single Occurrence
+// Given a string containing exactly one match,
+// When the function is called,
+// Then it should return 1.
+test("should count a single occurrence of a character", () => {
+  const str = "banana";
+  const char = "n";
+  const count = countChar(str, char);
+  expect(count).toEqual(2);
+});
+
 // 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.
+// Given a string with no matching character,
+// When the function is called,
+// Then it should return 0.
+test("should return 0 when the character does not occur", () => {
+  const str = "hello";
+  const char = "z";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+
+// Edge case: Empty String
+// Given an empty string,
+// When the function is called with any character,
+// Then it should return 0.
+test("should return 0 for an empty string", () => {
+  const str = "";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+
+// Edge case: Character at start and end
+// Given a string where the character appears at both ends,
+// When the function is called,
+// Then it should count both occurrences.
+test("should count characters at the start and end of the string", () => {
+  const str = "ahelloa";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(2);
+});

practice-tdd/get-ordinal-number.js

@@ -1,3 +1,23 @@
 export function getOrdinalNumber(num) {
-  return "1st";
+  const absNum = Math.abs(num);
+  const lastTwoDigits = absNum % 100;
+  const lastDigit = absNum % 10;
+
+  if (lastTwoDigits >= 11 && lastTwoDigits <= 13) {
+    return `${num}th`;
+  }
+
+  if (lastDigit === 1) {
+    return `${num}st`;
+  }
+
+  if (lastDigit === 2) {
+    return `${num}nd`;
+  }
+
+  if (lastDigit === 3) {
+    return `${num}rd`;
+  }
+
+  return `${num}th`;
 }

practice-tdd/get-ordinal-number.test.js

@@ -18,3 +18,23 @@ test("should append 'st' for numbers ending with 1, except those ending with 11"
   expect(getOrdinalNumber(21)).toEqual("21st");
   expect(getOrdinalNumber(131)).toEqual("131st");
 });
+
+test("should append 'nd' for numbers ending with 2, except those ending with 12", () => {
+  expect(getOrdinalNumber(2)).toEqual("2nd");
+  expect(getOrdinalNumber(22)).toEqual("22nd");
+  expect(getOrdinalNumber(102)).toEqual("102nd");
+});
+
+test("should append 'rd' for numbers ending with 3, except those ending with 13", () => {
+  expect(getOrdinalNumber(3)).toEqual("3rd");
+  expect(getOrdinalNumber(23)).toEqual("23rd");
+  expect(getOrdinalNumber(103)).toEqual("103rd");
+});
+
+test("should append 'th' for all other numbers, including 11, 12 and 13", () => {
+  expect(getOrdinalNumber(4)).toEqual("4th");
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(13)).toEqual("13th");
+  expect(getOrdinalNumber(111)).toEqual("111th");
+});

practice-tdd/repeat-str.js

@@ -1,5 +1,16 @@
-export function repeatStr() {
+export function repeatStr(str, count) {
   // Your implementation of this function must *not* call String.prototype.repeat (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/repeat).
   // The goal is to re-implement that function, not to use it.
-  return "hellohellohello";
+
+  if (count < 0) {
+    throw new Error("count must be non-negative");
+  }
+
+  let result = "";
+
+  for (let i = 0; i < count; i++) {
+    result += str;
+  }
+
+  return result;
 }

practice-tdd/repeat-str.test.js

@@ -20,13 +20,22 @@ test("should repeat the string count times", () => {
 // Given a target string `str` and a `count` equal to 1,
 // When the repeatStr function is called with these inputs,
 // Then it should return the original `str` without repetition.
+test("should return the original string when count is 1", () => {
+  expect(repeatStr("hello", 1)).toEqual("hello");
+});
 
 // Case: Handle count of 0:
 // Given a target string `str` and a `count` equal to 0,
 // When the repeatStr function is called with these inputs,
 // Then it should return an empty string.
+test("should return an empty string when count is 0", () => {
+  expect(repeatStr("hello", 0)).toEqual("");
+});
 
 // Case: Handle negative count:
 // Given a target string `str` and a negative integer `count`,
 // When the repeatStr function is called with these inputs,
 // Then it should throw an error, as negative counts are not valid.
+test("should throw an error for negative count", () => {
+  expect(() => repeatStr("hello", -1)).toThrow("count must be non-negative");
+});