fix: deprecate buffer property for now

Author: mikeal

src/cid.js

@@ -195,7 +195,6 @@ export default multiformats => {
       const [version, code, multihash] = decodeCID(bytes)
       Object.defineProperties(this, {
         // ArrayBufferView
-        buffer: property(bytes.buffer, { enumerable: false }),
         byteOffset: property(bytes.byteOffset, { enumerable: false }),
         byteLength: property(bytes.byteLength, { enumerable: false }),
 
@@ -217,6 +216,10 @@ export default multiformats => {
       throw new Error('"codec" property is deprecated, use integer "code" property instead')
     }
 
+    get buffer () {
+      throw new Error('Deprecated .buffer property, use .bytes to get Uint8Array instead')
+    }
+
     get multibaseName () {
       throw new Error('"multibaseName" property is deprecated')
     }

test/test-cid.js

@@ -444,4 +444,9 @@ describe('CID', () => {
     const encoded = varint.encode(2)
     await testThrow(() => CID.from(encoded), 'Invalid CID version 2')
   })
+  test('buffer', async () => {
+    const hash = await multihash.hash(Buffer.from('abc'), 'sha2-256')
+    const cid = CID.create(1, 112, hash)
+    await testThrow(() => cid.buffer, 'Deprecated .buffer property, use .bytes to get Uint8Array instead')
+  })
 })