fix: create safeJoin util for console wrappers (#1222)

Author: kamilogorek

src/console.js

@@ -1,3 +1,5 @@
+var utils = require('./utils');
+
 var wrapMethod = function(console, level, callback) {
   var originalConsoleLevel = console[level];
   var originalConsole = console;
@@ -11,13 +13,14 @@ var wrapMethod = function(console, level, callback) {
   console[level] = function() {
     var args = [].slice.call(arguments);
 
-    var msg = '' + args.join(' ');
+    var msg = utils.safeJoin(args, ' ');
     var data = {level: sentryLevel, logger: 'console', extra: {arguments: args}};
 
     if (level === 'assert') {
       if (args[0] === false) {
         // Default browsers message
-        msg = 'Assertion failed: ' + (args.slice(1).join(' ') || 'console.assert');
+        msg =
+          'Assertion failed: ' + (utils.safeJoin(args.slice(1), ' ') || 'console.assert');
         data.extra.arguments = args.slice(1);
         callback && callback(msg, data);
       }

src/utils.js

@@ -397,6 +397,28 @@ function fill(obj, name, replacement, track) {
   }
 }
 
+/**
+ * Join values in array
+ * @param input array of values to be joined together
+ * @param delimiter string to be placed in-between values
+ * @returns {string}
+ */
+function safeJoin(input, delimiter) {
+  if (!isArray(input)) return '';
+
+  var output = [];
+
+  for (var i = 0; i < input.length; i++) {
+    try {
+      output.push(String(input[i]));
+    } catch (e) {
+      output.push('[value cannot be serialized]');
+    }
+  }
+
+  return output.join(delimiter);
+}
+
 module.exports = {
   isObject: isObject,
   isError: isError,
@@ -423,5 +445,6 @@ module.exports = {
   isSameException: isSameException,
   isSameStacktrace: isSameStacktrace,
   parseUrl: parseUrl,
-  fill: fill
+  fill: fill,
+  safeJoin: safeJoin
 };

test/utils.test.js

@@ -23,6 +23,7 @@ var urlencode = utils.urlencode;
 var htmlTreeAsString = utils.htmlTreeAsString;
 var htmlElementAsString = utils.htmlElementAsString;
 var parseUrl = utils.parseUrl;
+var safeJoin = utils.safeJoin;
 
 describe('utils', function() {
   describe('isUndefined', function() {
@@ -421,4 +422,35 @@ describe('utils', function() {
       );
     });
   });
+
+  describe('safeJoin', function() {
+    it('should return empty string if not-array input provided', function() {
+      assert.equal(safeJoin('asd'), '');
+      assert.equal(safeJoin(undefined), '');
+      assert.equal(safeJoin({foo: 123}), '');
+    });
+
+    it('should default to comma, as regular join() call', function() {
+      assert.equal(safeJoin(['a', 'b', 'c']), 'a,b,c');
+    });
+
+    it('should stringify complex values, as regular String() call', function() {
+      assert.equal(
+        safeJoin([1, 'a', {foo: 42}, [1, 2, 3]], ' '),
+        '1 a [object Object] 1,2,3'
+      );
+    });
+
+    it('should still work with unserializeable values', function() {
+      function Foo() {}
+      Foo.prototype.toString = function() {
+        throw Error('whoops!');
+      };
+
+      assert.equal(
+        safeJoin([new Foo(), 'abc', new Foo(), 42], ' X '),
+        '[value cannot be serialized] X abc X [value cannot be serialized] X 42'
+      );
+    });
+  });
 });