used a simpler % test to get the last digits of a number, added tests for negative and non integer numbers

Author: asaniDev

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

@@ -1,33 +1,33 @@
 function getOrdinalNumber(num) {
-  const lastDigit = num.toString()[num.toString().length - 1];
+  if (Number.isInteger(num) && num >= 0) {
+    const lastDigit = num % 10;
 
-  if (lastDigit === "1") {
-    if (num === 11) {
-      return `${num}th`;
-    }
-
-    return `${num}st`;
-  } else if (lastDigit === "2") {
-    if (num.toString().length > 1) {
-      const last2Digits = num.toString().slice(-2);
-
-      if (last2Digits === "12") {
+    if (lastDigit === 1) {
+      if (num === 11) {
         return `${num}th`;
       }
-    }
-    return `${num}nd`;
-  } else if (lastDigit === "3") {
-    if (num.toString().length > 1) {
-      const last2Digits = num.toString().slice(-2);
 
-      if (last2Digits === "13") {
-        return `${num}th`;
+      return `${num}st`;
+    } else if (lastDigit === 2) {
+      if (num > 10) {
+        if (num % 100 === 12) {
+          return `${num}th`;
+        }
+      }
+      return `${num}nd`;
+    } else if (lastDigit === 3) {
+      if (num > 10) {
+        if (num % 100 === 13) {
+          return `${num}th`;
+        }
       }
+      return `${num}rd`;
     }
-    return `${num}rd`;
-  }
 
-  return `${num}th`;
+    return `${num}th`;
+  } else {
+    throw new Error("wrong input used please enter an integer from 0 upwards");
+  }
 }
 
 module.exports = getOrdinalNumber;

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

@@ -33,9 +33,24 @@ test("should append 'rd' to numbers with 3 at the end except for those ending wi
 });
 
 test("should append 'th' to all other numbers which do not end in 1,2,3,11,12 or 13", () => {
-  expect(getOrdinalNumber(10)).toEqual("10th");
+  expect(getOrdinalNumber(0)).toEqual("0th");
   expect(getOrdinalNumber(11)).toEqual("11th");
   expect(getOrdinalNumber(212)).toEqual("212th");
   expect(getOrdinalNumber(113)).toEqual("113th");
   expect(getOrdinalNumber(17)).toEqual("17th");
 });
+
+test("should throw an error if the input anything other than a positive integer", () => {
+  expect(() => getOrdinalNumber(1.09)).toThrow(
+    "wrong input used please enter an integer from 0 upwards"
+  );
+  expect(() => getOrdinalNumber("thirteen")).toThrow(
+    "wrong input used please enter an integer from 0 upwards"
+  );
+  expect(() => getOrdinalNumber(0.9)).toThrow(
+    "wrong input used please enter an integer from 0 upwards"
+  );
+  expect(() => getOrdinalNumber(-10)).toThrow(
+    "wrong input used please enter an integer from 0 upwards"
+  );
+});