implemented getOrdinalNumber and added tests

Author: Zadri415

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

@@ -1,5 +1,25 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  // Validate input: must be a number (not a string, null or undefined) and not NaN
+  if (typeof num !== "number" || Number.isNaN(num)) {
+    throw new TypeError("Input must be a number");
+  }
+
+  const abs = Math.abs(num);
+  const lastTwoDigits = abs % 100;
+  if (lastTwoDigits >= 11 && lastTwoDigits <= 13) {
+    return `${num}th`;
+  }
+  const lastDigit = lastTwoDigits % 10;
+  if (lastDigit === 1) {
+    return `${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

@@ -13,8 +13,61 @@ const getOrdinalNumber = require("./get-ordinal-number");
 // Case 1: Numbers ending with 1 (but not 11)
 // When the number ends with 1, except those ending with 11,
 // Then the function should return a string by appending "st" to the number.
-test("should append 'st' for numbers ending with 1, except those ending with 11", () => {
-  expect(getOrdinalNumber(1)).toEqual("1st");
-  expect(getOrdinalNumber(21)).toEqual("21st");
-  expect(getOrdinalNumber(131)).toEqual("131st");
+test("should append 'st' for numbers ending with 1, excluding 11", () => {
+  expect(getOrdinalNumber(1)).toBe("1st");
+  expect(getOrdinalNumber(21)).toBe("21st");
+  expect(getOrdinalNumber(101)).toBe("101st");
+  expect(getOrdinalNumber(131)).toBe("131st");
+});
+
+test("should append 'nd' for numbers ending with 2, excluding 12", () => {
+  expect(getOrdinalNumber(2)).toBe("2nd");
+  expect(getOrdinalNumber(22)).toBe("22nd");
+  expect(getOrdinalNumber(132)).toBe("132nd");
+});
+
+test("should append 'rd' for numbers ending with 3, excluding 13", () => {
+  expect(getOrdinalNumber(3)).toBe("3rd");
+  expect(getOrdinalNumber(23)).toBe("23rd");
+  expect(getOrdinalNumber(133)).toBe("133rd");
+});
+
+test("should append 'th' for numbers ending with 11, 12, or 13", () => {
+  expect(getOrdinalNumber(11)).toBe("11th");
+  expect(getOrdinalNumber(12)).toBe("12th");
+  expect(getOrdinalNumber(13)).toBe("13th");
+  expect(getOrdinalNumber(111)).toBe("111th");
+  expect(getOrdinalNumber(112)).toBe("112th");
+  expect(getOrdinalNumber(113)).toBe("113th");
+});
+
+test("should append 'th' for numbers ending with 4-9 or 0", () => {
+  expect(getOrdinalNumber(4)).toBe("4th");
+  expect(getOrdinalNumber(5)).toBe("5th");
+  expect(getOrdinalNumber(6)).toBe("6th");
+  expect(getOrdinalNumber(7)).toBe("7th");
+  expect(getOrdinalNumber(8)).toBe("8th");
+  expect(getOrdinalNumber(9)).toBe("9th");
+  expect(getOrdinalNumber(0)).toBe("0th");
+});
+
+test("non-integer and negative numbers should be handled correctly", () => {
+  expect(getOrdinalNumber(1.5)).toBe("1.5th");
+  expect(getOrdinalNumber(-2.3)).toBe("-2.3th");
+  expect(getOrdinalNumber(-11)).toBe("-11th");
+});
+
+test("invalid input should throw an error", () => {
+  expect(() => getOrdinalNumber("string")).toThrow("Input must be a number");
+  expect(() => getOrdinalNumber(null)).toThrow("Input must be a number");
+  expect(() => getOrdinalNumber(undefined)).toThrow("Input must be a number");
+});
+
+test("NaN input should throw an error", () => {
+  expect(() => getOrdinalNumber(NaN)).toThrow("Input must be a number");
+});
+
+test("Infinity input should be handled correctly", () => {
+  expect(getOrdinalNumber(Infinity)).toBe("Infinityth");
+  expect(getOrdinalNumber(-Infinity)).toBe("-Infinityth");
 });