Add support for big numbers

README.md

@@ -92,6 +92,10 @@ client.getInfo().then(([body, headers]) => console.log(body, headers));
 const [body, headers] = await client.getInfo();
 ```
 
+### Floating point number precision in JavaScript
+
+Due to [Javascript's limited floating point precision](http://floating-point-gui.de/), all big numbers (numbers with more than 15 significant digits) are returned as strings to prevent precision loss.
+
 ### Version Checking
 By default, all methods are exposed on the client independently of the version it is connecting to. This is the most flexible option as defining methods for unavailable RPC calls does not cause any harm and the library is capable of handling a `Method not found` response error correctly.
 

package.json

@@ -38,6 +38,7 @@
     "@uphold/request-logger": "^1.2.0",
     "bluebird": "^3.4.1",
     "debugnyan": "^1.0.0",
+    "json-bigint": "^0.2.0",
     "lodash": "^4.0.0",
     "request": "^2.53.0",
     "semver": "^5.1.0",

src/index.js

@@ -3,6 +3,7 @@
  * Module dependencies.
  */
 
+import JSONBigInt from 'json-bigint';
 import Parser from './parser';
 import Promise from 'bluebird';
 import Requester from './requester';
@@ -12,6 +13,12 @@ import methods from './methods';
 import requestLogger from './logging/request-logger';
 import semver from 'semver';
 
+/**
+ * JSONBigInt parser.
+ */
+
+const { stringify } = JSONBigInt({ storeAsString: true, strict: true }); // eslint-disable-line new-cap
+
 /**
  * Source arguments to find out if a callback has been passed.
  */
@@ -122,7 +129,8 @@ class Client {
 
       return this.request.postAsync({
         auth: _.pickBy(this.auth, _.identity),
-        body,
+        body: stringify(body),
+        json: false,
         uri: '/'
       })
       .bind(this)

src/logging/request-obfuscator.js

@@ -3,9 +3,16 @@
  * Module dependencies.
  */
 
+import JSONBigInt from 'json-bigint';
 import methods from '../methods';
 import { defaults, get, has, isArray, isEmpty, isString, map, mapKeys } from 'lodash';
 
+/**
+ * JSONBigInt parser.
+ */
+
+const { parse, stringify } = JSONBigInt({ storeAsString: true, strict: true }); // eslint-disable-line new-cap
+
 /**
  * Map all methods to lowercase.
  */
@@ -83,15 +90,15 @@ function obfuscateRequest(request) {
     return;
   }
 
-  request.body = JSON.parse(request.body);
+  request.body = parse(request.body);
 
   if (isArray(request.body)) {
     request.body = map(request.body, obfuscateRequestBody);
   } else {
     request.body = obfuscateRequestBody(request.body);
   }
 
-  request.body = JSON.stringify(request.body);
+  request.body = stringify(request.body);
 }
 
 /**

src/parser.js

@@ -3,9 +3,16 @@
  * Module dependencies.
  */
 
+import JSONBigInt from 'json-bigint';
 import RpcError from './errors/rpc-error';
 import _ from 'lodash';
 
+/**
+ * JSONBigInt parser.
+ */
+
+const { parse } = JSONBigInt({ storeAsString: true, strict: true }); // eslint-disable-line new-cap
+
 /**
  * Get response result and errors.
  */
@@ -52,6 +59,9 @@ export default class Parser {
       throw new RpcError(response.statusCode);
     }
 
+    // Parsing the body with custom parser to support BigNumbers.
+    body = 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();
       });
     });
 

test/logging/request-obfuscator_test.js

@@ -27,6 +27,14 @@ describe('RequestObfuscator', () => {
       request.should.eql({ headers: { authorization: 'Basic ******' } });
     });
 
+    it('should keep a bignumber precision in `request.body`', () => {
+      const request = { body: '{"id":"1485369469422","method":"foobar","params":[9223372036854775807]}' };
+
+      obfuscate(request);
+
+      request.should.eql({ body: '{"id":"1485369469422","method":"foobar","params":["9223372036854775807"]}' });
+    });
+
     it('should obfuscate the private key from `request.body` when `method` is `importprivkey`', () => {
       const request = { body: '{"id":"1485369469422","method":"importprivkey","params":["foobar"]}' };