test: check for non-enumerability of asCID property

Author: achingbrain

test/test-cid.spec.js

@@ -696,4 +696,12 @@ describe('CID', () => {
     const encoded = varint.encodeTo(2, new Uint8Array(32))
     assert.throws(() => CID.decode(encoded), 'Invalid CID version 2')
   })
+
+  it('asCID is non-enumerable', () => {
+    const cid = CID.parse('bafybeif2pall7dybz7vecqka3zo24irdwabwdi4wc55jznaq75q7eaavvu')
+
+    assert.isFalse(Object.prototype.propertyIsEnumerable.call(cid, 'asCID'))
+    assert.isFalse(Object.keys(cid).includes('asCID'))
+    assert.equal(cid.asCID, cid)
+  })
 })