implement getOrdinalNumber function and add tests

Author: jakr-s

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

@@ -1,5 +1,21 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  const remainderTen = num % 10;
+  const remainderHundred = num % 100;
+
+  if (remainderHundred >= 11 && remainderHundred <= 13) {
+    return `${num}th`;
+  }
+
+  switch (remainderTen) {
+    case 1:
+      return `${num}st`;
+    case 2:
+      return `${num}nd`;
+    case 3:
+      return `${num}rd`;
+    default:
+      return `${num}th`;
+  }
 }
 
 module.exports = getOrdinalNumber;

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

@@ -11,3 +11,31 @@ const getOrdinalNumber = require("./get-ordinal-number");
 test("should return '1st' for 1", () => {
   expect(getOrdinalNumber(1)).toEqual("1st");
 });
+
+test("should return '2nd' for 2", () => {
+  expect(getOrdinalNumber(2)).toEqual("2nd");
+});
+
+test("should return '3rd' for 3", () => {
+  expect(getOrdinalNumber(3)).toEqual("3rd");
+});
+
+test("should return '4th' for 4", () => {
+  expect(getOrdinalNumber(4)).toEqual("4th");
+});
+
+test("should return '11th' for 11", () => {
+  expect(getOrdinalNumber(11)).toEqual("11th");
+});
+
+test("should return '12th' for 12", () => {
+  expect(getOrdinalNumber(12)).toEqual("12th");
+});
+
+test("should return '13th' for 13", () => {
+  expect(getOrdinalNumber(13)).toEqual("13th");
+});
+
+test("should return '111th' for 111", () => {
+  expect(getOrdinalNumber(111)).toEqual("111th");
+});