Support bignumber response parsing

package.json

@@ -36,6 +36,7 @@
   },
   "dependencies": {
     "bluebird": "^3.4.1",
+    "json-bigint": "^0.2.0",
     "lodash": "^4.0.0",
     "request": "^2.53.0",
     "semver": "^5.1.0",

src/index.js

@@ -118,7 +118,8 @@ class Client {
 
       return this.request.postAsync({
         auth: _.pickBy(this.auth, _.identity),
-        body,
+        body: JSON.stringify(body),
+        json: false,
         uri: '/'
       })
       .bind(this)

src/parser.js

@@ -5,6 +5,7 @@
 
 import RpcError from './errors/rpc-error';
 import _ from 'lodash';
+import jsonBigInt from 'json-bigint';
 
 /**
  * Get response result and errors.
@@ -52,6 +53,9 @@ export default class Parser {
       throw new RpcError(response.statusCode);
     }
 
+    // Parsing the body with custom parser to support BigNumbers.
+    body = jsonBigInt({ storeAsString: true }).parse(body);
+
     if (!Array.isArray(body)) {
       return get(body, { headers: this.headers, response });
     }

test/index_test.js

@@ -199,7 +199,7 @@ describe('Client', () => {
       it('should return the proof-of-work difficulty', async () => {
         const difficulty = await new Client(config.bitcoind).getDifficulty();
 
-        difficulty.should.be.a.Number();
+        difficulty.should.be.a.String();
       });
     });