West Midlands | ITP-Sept-2025 | Ali Naru | Sprint 3 | coursework/sprint-3-practice-tdd

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

@@ -1,5 +1,14 @@
 function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  let count = 0;
+
+  for (let char of stringOfCharacters) {
+    if (char === 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 the case-sensitive str,
 // When the function is called with these inputs,
 // Then it should return 0, indicating that no occurrences of the char were found in the case-sensitive str.
+
+test("should return 0 when character does not occur in the string", () => {
+  const str = "hello";
+  const char = "z";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});

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

@@ -1,5 +1,17 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  const lastDigit = num % 10;
+  const lastTwoDigits = num % 100;
+
+  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`;
 }
 
 module.exports = getOrdinalNumber;

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

@@ -1,13 +1,55 @@
 const getOrdinalNumber = require("./get-ordinal-number");
-// In this week's prep, we started implementing getOrdinalNumber
 
-// continue testing and implementing getOrdinalNumber for additional cases
-// Write your tests using Jest - remember to run your tests often for continual feedback
+// Category 1: Numbers ending in 11, 12, 13 → always "th"
+test("appends 'th' to numbers ending in 11, 12, or 13", () => {
+  const numbers = [11, 12, 13, 111, 1012, 1313];
+  numbers.forEach(num => {
+    expect(getOrdinalNumber(num)).toEqual(`${num}th`);
+  });
+});
+
+// Category 2: Numbers ending in 1 → "st" (except those ending in 11)
+test("appends 'st' to numbers ending in 1 except those ending in 11", () => {
+  const numbers = [1, 21, 101, 1001];
+  numbers.forEach(num => {
+    expect(getOrdinalNumber(num)).toEqual(`${num}st`);
+  });
+});
 
-// Case 1: Identify the ordinal number for 1
-// When the number is 1,
-// Then the function should return "1st"
+// Category 3: Numbers ending in 2 → "nd" (except those ending in 12)
+test("appends 'nd' to numbers ending in 2 except those ending in 12", () => {
+  const numbers = [2, 22, 102, 202];
+  numbers.forEach(num => {
+    expect(getOrdinalNumber(num)).toEqual(`${num}nd`);
+  });
+});
+
+// Category 4: Numbers ending in 3 → "rd" (except those ending in 13)
+test("appends 'rd' to numbers ending in 3 except those ending in 13", () => {
+  const numbers = [3, 23, 103, 1003];
+  numbers.forEach(num => {
+    expect(getOrdinalNumber(num)).toEqual(`${num}rd`);
+  });
+});
+
+// Category 5: All other numbers → "th"
+test("appends 'th' to numbers that don't meet special suffix rules", () => {
+  const numbers = [4, 5, 6, 9, 20, 100, 1004, 1009];
+  numbers.forEach(num => {
+    expect(getOrdinalNumber(num)).toEqual(`${num}th`);
+  });
+});
+
+// Error handling - Non-integers
+test("throws an error when number is not an integer", () => {
+  const invalidInputs = [1.5, "3", null, undefined, {}, [], NaN];
+
+  invalidInputs.forEach(input => {
+    expect(() => getOrdinalNumber(input)).toThrow("Input must be an integer");
+  });
+});
 
-test("should return '1st' for 1", () => {
-  expect(getOrdinalNumber(1)).toEqual("1st");
+// Error handling - Negative values
+test("throws an error when number is negative", () => {
+  expect(() => getOrdinalNumber(-1)).toThrow("Input must be a non-negative integer");
 });

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

@@ -1,5 +1,8 @@
-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

@@ -1,32 +1,31 @@
-// Implement a function repeatStr
-const repeatStr = require("./repeat-str");
-// Given a target string str and a positive integer count,
-// When the repeatStr function is called with these inputs,
-// Then it should:
-
-// case: repeat String:
-// Given a target string str and a positive integer count,
-// When the repeatStr function is called with these inputs,
-// Then it should repeat the str count times and return a new string containing the repeated str values.
-
-test("should repeat the string count times", () => {
-  const str = "hello";
-  const count = 3;
-  const repeatedStr = repeatStr(str, count);
-  expect(repeatedStr).toEqual("hellohellohello");
-});
-
 // case: handle Count of 1:
 // 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, ensuring that a count of 1 results in no repetition.
+test("should return 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, ensuring that a count of 0 results in an empty output.
+test("should return empty string when count is 0", () => {
+  const str = "hello";
+  const count = 0;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("");
+});
 
 // case: 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 or return an appropriate error message, as negative counts are not valid.
+test("should throw an error for negative count", () => {
+  const str = "hello";
+  const count = -3;
+  expect(() => repeatStr(str, count)).toThrow();
+});