London | JAN-2026 ITP | Asha Ahmed | Sprint 3 | practice TDD coursework

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

@@ -1,5 +1,11 @@
 function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  let count = 0;
+  for (const character of stringOfCharacters) {
+    if (character === findCharacter) {
+      count++;
+    }
+  }
+  return count;
 }
 
 module.exports = countChar;

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

@@ -22,3 +22,10 @@ test("should count multiple occurrences of a character", () => {
 // 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 0, since there are no occurrences of a character", () => {
+  const char = "a";
+  const str = "AABBCCDEFF";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});

Sprint-3/2-practice-tdd/get-ordinal-number.js

@@ -1,5 +1,23 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  const last2Digits = String(num).slice(-2);
+  if (["11", "12", "13"].includes(last2Digits)) return `${num}th`;
+
+  const lastDigit = String(num).slice(-1);
+  let ordinalResult = "";
+  switch (lastDigit) {
+    case "1":
+      ordinalResult = `${num}st`;
+      break;
+    case "2":
+      ordinalResult = `${num}nd`;
+      break;
+    case "3":
+      ordinalResult = `${num}rd`;
+      break;
+    default:
+      ordinalResult = `${num}th`;
+  }
+  return ordinalResult;
 }
 
 module.exports = getOrdinalNumber;

Sprint-3/2-practice-tdd/get-ordinal-number.test.js

@@ -18,3 +18,41 @@ test("should append 'st' for numbers ending with 1, except those ending with 11"
   expect(getOrdinalNumber(21)).toEqual("21st");
   expect(getOrdinalNumber(131)).toEqual("131st");
 });
+
+// Case 2: Numbers ending with 2 (but not 12)
+// When the number ends with 2, except those ending with 12,
+// Then the function should return a string by appending "nd" to the number.
+test("should append 'nd' for numbers ending with 2, except those ending with 12", () => {
+  expect(getOrdinalNumber(2)).toEqual("2nd");
+  expect(getOrdinalNumber(3162)).toEqual("3162nd");
+  expect(getOrdinalNumber(7322)).toEqual("7322nd");
+});
+
+// Case 3: Numbers ending with 3 (but not 13)
+// When the number ends with 3, except those ending with 13,
+// Then the function should return a string by appending "rd" to the number.
+test("should append 'rd' for numbers ending with 3, except those ending with 13", () => {
+  expect(getOrdinalNumber(3)).toEqual("3rd");
+  expect(getOrdinalNumber(3243)).toEqual("3243rd");
+  expect(getOrdinalNumber(133)).toEqual("133rd");
+});
+
+// Case 4: Numbers ending with 11, 12 or 13
+// When the number ends with 11, 12 or 13
+// Then the function should return a string by appending "th" to the number.
+test("should append 'th' for numbers with 11, 12 or 13", () => {
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(211)).toEqual("211th");
+  expect(getOrdinalNumber(2113)).toEqual("2113th");
+  expect(getOrdinalNumber(824312)).toEqual("824312th");
+});
+
+// Case 4: Numbers not ending in 1, 2 and 3
+// When the number ends with 0, 4, 5, 6, 7, 8, 9
+// Then the function should return a string by appending "th" to the number.
+test("should append 'th' for numbers not ending in 1, 2 and 3", () => {
+  expect(getOrdinalNumber(19)).toEqual("19th");
+  expect(getOrdinalNumber(2118)).toEqual("2118th");
+  expect(getOrdinalNumber(3130)).toEqual("3130th");
+  expect(getOrdinalNumber(924334)).toEqual("924334th");
+});

Sprint-3/2-practice-tdd/repeat-str.js

@@ -1,5 +1,6 @@
-function repeatStr() {
-  return "hellohellohello";
+function repeatStr(str, count) {
+  if (count < 0) throw new Error("Count cannot be negative");
+  return str.repeat(count);
 }
 
 module.exports = repeatStr;

Sprint-3/2-practice-tdd/repeat-str.test.js

@@ -21,12 +21,30 @@ test("should repeat the string count times", () => {
 // 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");
+  expect(repeatStr("h", 1)).toEqual("h");
+  expect(repeatStr("", 1)).toEqual("");
+});
+
 // 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 empty string when count is 0", () => {
+  expect(repeatStr("hello", 0)).toEqual("");
+  expect(repeatStr("any", 0)).toEqual("");
+  expect(repeatStr("", 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 error when count is negative", () => {
+  expect(() => repeatStr("hello", -1)).toThrow();
+  expect(() => repeatStr("test", -5)).toThrow();
+  expect(() => repeatStr("", -3)).toThrow();
+});