Fix decoding of empty object.

- Enable test to decode empty object.
- Map.entries doesn't take argument.
- Remove instanceof Map check since API requires a Map.
- Normalize data to a Buffer since 'cbor' library requires one.
- Normalize `cbor.decode` result value to a Map. It returns just an
  object when decoding an empty object. Simplifies later Map vs object
  usage.

CHANGELOG.md

@@ -1,5 +1,10 @@
 # @digitalbazaar/cborld ChangeLog
 
+## 1.0.1 - 2020-xx-xx
+
+### Fixed
+- Handle decoding of encoded empty object.
+
 ## 1.0.0 - 2020-07-23
 
 ### Note

lib/context.js

@@ -56,8 +56,8 @@ export function getJsonldContextUrls({jsonldDocument}) {
 export function getCborldContextUrls({cborMap, appContextMap}) {
   const contextUrls = [];
 
-  for(const [key, value] of cborMap.entries(cborMap)) {
-    if(cborMap instanceof Map && key === 1) {
+  for(const [key, value] of cborMap.entries()) {
+    if(key === 1) {
       const contexts = Array.isArray(value) ? value : [value];
       contexts.forEach(element => {
         const encodedContext = new ContextCodec();

lib/decode.js

@@ -25,7 +25,14 @@ import util from 'util';
  */
 export async function fromCborld({
   cborldBytes, documentLoader, appContextMap, diagnose}) {
-  const cborMap = cbor.decode(cborldBytes);
+  // normalize bytes to a Buffer for 'cbor'
+  const _cborldBytes =
+    cborldBytes instanceof Buffer ? cborldBytes : Buffer.from(cborldBytes);
+  const cborMap = cbor.decode(_cborldBytes);
+  // normalize value to a Map
+  if(!(cborMap.value instanceof Map)) {
+    cborMap.value = new Map(Object.entries(cborMap.value));
+  }
 
   let jsonldDocument = {};
   if(cborMap.tag === 0x0500) {

tests/test.spec.js

@@ -12,24 +12,26 @@ global.should = chai.should();
 
 import {
   encode,
-  decode
+  decode,
+  documentLoader
 } from '..';
 
 describe('cborld', () => {
   describe('encode', () => {
     it('should encode an empty JSON-LD Document', async () => {
       const jsonldDocument = {};
-      const cborldBytes = await encode({jsonldDocument});
-      expect(cborldBytes).to.equalBytes('d90501a0');
+      const cborldBytes = await encode({jsonldDocument, documentLoader});
+      expect(cborldBytes).instanceof(Uint8Array);
+      expect(cborldBytes).equalBytes('d90501a0');
     });
     it.skip('should encode a simple JSON-LD Document', async () => {
     });
   });
   describe('decode', () => {
-    it.skip('should decode empty document CBOR-LD bytes', async () => {
+    it('should decode empty document CBOR-LD bytes', async () => {
       const cborldBytes = new Uint8Array([0xd9, 0x05, 0x01, 0xa0]);
-      const jsonldDocument = await decode({cborldBytes});
-      expect(jsonldDocument).to.deepEqual({});
+      const jsonldDocument = await decode({cborldBytes, documentLoader});
+      expect(jsonldDocument).deep.equal({});
     });
     it.skip('should decode simple CBOR-LD bytes', async () => {
     });