London | ITP-JAN-2026 | Said Fayaz Sadat | Sprint 3 | coursework/sprint-3/practise-tdd

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

@@ -1,5 +1,18 @@
 function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  if (typeof stringOfCharacters !== "string") {
+    throw new Error("First argument must be a string");
+  }
+  if (typeof findCharacter !== "string" || findCharacter.length !== 1) {
+    throw new Error("Second argument must be a single character");
+  }
+
+  let count = 0;
+  for (const char of stringOfCharacters) {
+    if (char === findCharacter) {
+      count++;
+    }
+  }
+  return count;
 }
 
-module.exports = countChar;
+module.exports = countChar;

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

@@ -22,3 +22,33 @@ 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 when the character does not occur in the string", () => {
+  const str = "hello world";
+  const char = "x";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+}); 
+
+// Case: Case sensitivity
+test("should count characters in a case-sensitive way", () => {
+  const str = "Hello World";
+  const char = "h"; // lowercase 'h' does not match 'H'
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+
+// Case: Non-alphabet characters
+test("should count non-alphabet characters", () => {
+  const str = "123!@#123!";
+  const char = "1";
+  const count = countChar(str, char);
+  expect(count).toEqual(2);
+});
+
+// Case: Spaces
+test("should count spaces correctly", () => {
+  const str = "a b c d e f g";
+  const char = " ";
+  const count = countChar(str, char);
+  expect(count).toEqual(6);
+});

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

@@ -1,5 +1,15 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  const lastTwo = num % 100; // handle teen exceptions
+  if (lastTwo === 11 || lastTwo === 12 || lastTwo === 13) {
+    return num + "th";
+  }
+
+  const lastDigit = num % 10;
+  if (lastDigit === 1) return num + "st";
+  if (lastDigit === 2) return num + "nd";
+  if (lastDigit === 3) return num + "rd";
+
+  return num + "th";
 }
 
 module.exports = getOrdinalNumber;

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

@@ -18,3 +18,43 @@ 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)
+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(132)).toEqual("132nd");
+});
+test("should append 'th' for numbers ending with 2 that are also ending with 12", () => {
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(112)).toEqual("112th");
+});
+
+// Case 3: Numbers ending with 3 (but not 13)
+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(133)).toEqual("133rd");
+});
+test("should append 'th' for numbers ending with 11, 12, or 13", () => {
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(13)).toEqual("13th");
+  expect(getOrdinalNumber(111)).toEqual("111th");
+  expect(getOrdinalNumber(112)).toEqual("112th");
+  expect(getOrdinalNumber(113)).toEqual("113th");
+});
+
+// Case 4: All other numbers
+
+ test("should append 'th' for numbers that do not follow the 1, 2, 3 rule", () => {
+  // Single digits 4-10
+  expect(getOrdinalNumber(4)).toEqual("4th");
+  expect(getOrdinalNumber(5)).toEqual("5th");
+  expect(getOrdinalNumber(6)).toEqual("6th");
+  expect(getOrdinalNumber(7)).toEqual("7th");
+  expect(getOrdinalNumber(8)).toEqual("8th");
+  expect(getOrdinalNumber(9)).toEqual("9th");
+  expect(getOrdinalNumber(10)).toEqual("10th"); 
+ });

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

@@ -1,5 +1,22 @@
-function repeatStr() {
-  return "hellohellohello";
+function repeatStr(str, count) {
+  if (count < 0) {
+    throw new Error("Count cannot be negative");
+  }
+
+  if (count === 0) {
+    return "";
+  }
+
+  if (count === 1) {
+    return str;
+  }
+
+  let result = "";
+  for (let i = 0; i < count; i++) {
+    result += str;
+  }
+
+  return result;
 }
 
-module.exports = repeatStr;
+module.exports = repeatStr;

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

@@ -20,13 +20,30 @@ 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", () => {
+  const str = "hello";
+  const count = 1;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).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", () => {
+  const str = "hello";
+  const count = 0;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).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 when count is negative", () => {
+  const str = "hello";
+  const count = -1;
+  expect(() => repeatStr(str, count)).toThrow();
+});