Fix tenth ordinal (#84)

* chore: yarn file

* refactor: spacing refactor

* chore: helper function to check if the number ends with tenth

* chore: add test cases for numbers ending with a 10th

* chore: add functionality to check for 10th number before going into switch cases

* add code from existing PR with updated versions

* add missing link to math.md doc

* test case for switch case default

Author: thelebdev

docs/math.md

@@ -10,6 +10,7 @@
 * [`pow`](#pow)
 * [`sqrt`](#sqrt)
 * [`abs`](#abs)
+* [`ordinal`](#ordinal)
 
 You can check the module import [`here`](./modules.md).
 

src/math/ordinal.pipe.spec.ts

@@ -1,35 +1,54 @@
 import { OrdinalPipe } from './ordinal.pipe';
 
 describe('OrdinalPipe', () => {
-    
+
     let pipe: OrdinalPipe;
-    
+
     beforeEach(() => {
-       pipe = new OrdinalPipe(); 
+        pipe = new OrdinalPipe();
     });
-    
+
     it('Should return 123rd', () => {
-        
+
         expect(pipe.transform(123)).toEqual('123rd');
     });
 
     it('Should return 221st', () => {
-        
+
         expect(pipe.transform(221)).toEqual('221st');
     });
-    
+
     it('Should return 2nd', () => {
-       
-        expect(pipe.transform(2)).toEqual('2nd'); 
+
+        expect(pipe.transform(2)).toEqual('2nd');
     });
 
     it('Should return 15th', () => {
-       
-        expect(pipe.transform(15)).toEqual('15th'); 
+
+        expect(pipe.transform(15)).toEqual('15th');
+    });
+
+    it('Should return 11th', () => {
+
+        expect(pipe.transform(11)).toEqual('11th');
+    });
+
+    it('Should return 12th', () => {
+
+        expect(pipe.transform(12)).toEqual('12th');
+    });
+
+    it('Should return 133313th', () => {
+
+        expect(pipe.transform(133313)).toEqual('133313th');
     });
 
     it('Should return NaN', () => {
         expect(pipe.transform('a')).toEqual('NaN');
     });
-  
+
+    it('Should return 35th', () => {
+        expect(pipe.transform(35)).toEqual('35th');
+    });
+
 });

src/math/ordinal.pipe.ts

@@ -1,29 +1,38 @@
-import { Pipe, PipeTransform  } from '@angular/core';
+import { Pipe, PipeTransform } from '@angular/core';
 import { isNumberFinite } from '../utils/utils';
 
 @Pipe({
-  name: 'ordinal'
+    name: 'ordinal'
 })
 export class OrdinalPipe implements PipeTransform {
-  
-    transform (input: any): any {
+
+    transform(input: any): any {
 
         if (!isNumberFinite(input)) {
             return 'NaN';
         }
 
-        const cardinal = input.toString().charAt(input.toString().length - 1);
+        if (this.endsWithTenth(input)) {
+            return input + 'th';
+        } else {
+            const cardinal = input.toString().charAt(input.toString().length - 1);
 
-        switch(cardinal) {
-            case '1':
-                return input + 'st';
-            case '2':
-                return input + 'nd';
-            case '3':
-                return input + 'rd';
-            default: 
-                return input + 'th';
-        }
-        
+            switch (cardinal) {
+                case '1':
+                    return input + 'st';
+                case '2':
+                    return input + 'nd';
+                case '3':
+                    return input + 'rd';
+                default:
+                    return input + 'th';
+            }
+        } 
+    }
+            
+    private endsWithTenth(input: any): boolean {
+        const beforeLastDigit = input.toString().charAt(input.toString().length - 2);
+
+        return beforeLastDigit === '1';
     }
 }