parity.js interfaces for vaults (#4497)

js/src/api/format/output.js

@@ -17,6 +17,7 @@
 import BigNumber from 'bignumber.js';
 
 import { toChecksumAddress } from '../../abi/util/address';
+import { isString } from '../util/types';
 
 export function outAccountInfo (infos) {
   return Object
@@ -344,3 +345,17 @@ export function outTraceReplay (trace) {
 
   return trace;
 }
+
+export function outVaultMeta (meta) {
+  if (isString(meta)) {
+    try {
+      const obj = JSON.parse(meta);
+
+      return obj;
+    } catch (error) {
+      return {};
+    }
+  }
+
+  return meta || {};
+}

js/src/api/format/output.spec.js

@@ -16,7 +16,7 @@
 
 import BigNumber from 'bignumber.js';
 
-import { outBlock, outAccountInfo, outAddress, outChainStatus, outDate, outHistogram, outNumber, outPeer, outPeers, outReceipt, outSyncing, outTransaction, outTrace } from './output';
+import { outBlock, outAccountInfo, outAddress, outChainStatus, outDate, outHistogram, outNumber, outPeer, outPeers, outReceipt, outSyncing, outTransaction, outTrace, outVaultMeta } from './output';
 import { isAddress, isBigNumber, isInstanceOf } from '../../../test/types';
 
 describe('api/format/output', () => {
@@ -455,4 +455,22 @@ describe('api/format/output', () => {
       expect(formatted.transactionPosition.toNumber()).to.equal(11);
     });
   });
+
+  describe('outVaultMeta', () => {
+    it('returns an exmpt object on null', () => {
+      expect(outVaultMeta(null)).to.deep.equal({});
+    });
+
+    it('returns the original value if not string', () => {
+      expect(outVaultMeta({ test: 123 })).to.deep.equal({ test: 123 });
+    });
+
+    it('returns an object from JSON string', () => {
+      expect(outVaultMeta('{"test":123}')).to.deep.equal({ test: 123 });
+    });
+
+    it('returns an empty object on invalid JSON', () => {
+      expect(outVaultMeta('{"test"}')).to.deep.equal({});
+    });
+  });
 });