catch JSON parsing errors in fbgraph

lib/graph.js

@@ -190,12 +190,17 @@ Graph.prototype.get = function () {
       return;
     }
 
-    body = { ...JSON.parse(body), headers: res.headers };
-    if (~res.headers['content-type'].indexOf('image')) {
-      body = {
-          image: true
-        , headers: res.headers
-      };
+    if (res.headers['content-type'] && ~res.headers['content-type'].indexOf('image')) {
+        body = {
+            image: true
+          , headers: res.headers
+        };
+    } else {
+        try {
+            body = { ...JSON.parse(body), headers: res.headers };
+        } catch (e) {
+            // parsing failed, pass raw body to end()
+        }
     }
 
     self.end(body);
@@ -233,7 +238,11 @@ Graph.prototype.post = function() {
       return;
     }
 
-    body = { ...JSON.parse(body), headers: res.headers };
+    try {
+        body = { ...JSON.parse(body), headers: res.headers };
+    } catch (e) {
+        // if parsing fails, we pass the raw body to end()
+    }
     self.end(body);
   })
   .on('error', (err) => {

tests/graph.test.js

@@ -2,7 +2,8 @@ var graph    = require("../index")
   , FBConfig = require("./config").facebook
   , vows     = require("vows")
   , events   = require("events")
-  , assert   = require("assert");
+  , assert   = require("assert")
+  , request  = require("request");
 
 
 var testUser1      = {}
@@ -277,6 +278,31 @@ vows.describe("graph.test").addBatch({
       }
     }
   }
+}).addBatch({
+    "Hardening JSON Parsing": {
+        "When receiving a non-JSON response": {
+            topic: function() {
+                var callback = this.callback;
+                var originalGet = request.get;
+
+                request.get = function(options, cb) {
+                    var res = { headers: { 'content-type': 'text/html' } };
+                    var body = '{"foo": bar}'; // Malformed JSON
+                    setImmediate(function() { cb(null, res, body); });
+                    return { on: function() { return this; } };
+                };
+
+                graph.get('/me', function(err, res) {
+                    request.get = originalGet;
+                    callback(err, res);
+                });
+            },
+            "it should return an error instead of crashing": function(err, res) {
+                assert.isNotNull(err);
+                assert.equal(err.message, 'Error parsing json');
+            }
+        }
+    }
 }).addBatch({
   "When tests are over": {
     topic: function () {