Add enum.isValid

2 files changed, 15 insertions, 2 deletions

diff --git a/app/lib/enum.js b/app/lib/enum.js
index 4359c3bfb3..c2042c07fa 100644
--- a/app/lib/enum.js
+++ b/app/lib/enum.js
@@ -2,15 +2,20 @@
  * Creates enum object with keys provided as arguments
  */
 export default function Enum() {
-  let object = {};
+  let object = Object.create({});
+  const keys = [...arguments];
 
-  for(const key of arguments) {
+  for(const key of keys) {
     Object.defineProperty(object, key, {
       enumerable: true,
       value: key,
       writable: false
     });
   }
+  
+  Object.defineProperty(object, 'isValid', {
+    value: (e) => keys.includes(e)
+  });
 
   Object.freeze(object);
 
diff --git a/test/lib/enum.spec.js b/test/lib/enum.spec.js
index 04e1015f42..0f5d6ee4d1 100644
--- a/test/lib/enum.spec.js
+++ b/test/lib/enum.spec.js
@@ -13,4 +13,12 @@ describe('enum', () => {
     expect(() => e.ANYWHERE = 'ANYWHERE').to.throw();
   });
 
+  it('should be able to validate enum keys', () => {
+    let e = Enum('NORTH', 'SOUTH', 'WEST', 'EAST');
+    expect(e.isValid('SOUTH')).to.be.true;
+    expect(e.isValid('ANYWHERE')).to.be.false;
+    expect(e.isValid()).to.be.false;
+    expect(e.isValid(null)).to.be.false;
+  })
+
 });