repl: Use a domain to catch async errors safely

Fix #2031

lib/repl.js

@@ -49,6 +49,7 @@ var fs = require('fs');
 var rl = require('readline');
 var Console = require('console').Console;
 var EventEmitter = require('events').EventEmitter;
+var domain = require('domain');
 
 // If obj.hasOwnProperty has been overridden, then calling
 // obj.hasOwnProperty(prop) will break.
@@ -81,7 +82,7 @@ function REPLServer(prompt, stream, eval_, useGlobal, ignoreUndefined) {
 
   EventEmitter.call(this);
 
-  var options, input, output;
+  var options, input, output, dom;
   if (typeof prompt == 'object') {
     // an options object was given
     options = prompt;
@@ -92,6 +93,7 @@ function REPLServer(prompt, stream, eval_, useGlobal, ignoreUndefined) {
     useGlobal = options.useGlobal;
     ignoreUndefined = options.ignoreUndefined;
     prompt = options.prompt;
+    dom = options.domain;
   } else if (typeof prompt != 'string') {
     throw new Error('An options Object, or a prompt String are required');
   } else {
@@ -100,10 +102,14 @@ function REPLServer(prompt, stream, eval_, useGlobal, ignoreUndefined) {
 
   var self = this;
 
+  self._domain = dom || domain.create();
+
   self.useGlobal = !!useGlobal;
   self.ignoreUndefined = !!ignoreUndefined;
 
-  self.eval = eval_ || function(code, context, file, cb) {
+  eval_ = eval_ || defaultEval;
+
+  function defaultEval(code, context, file, cb) {
     var err, result;
     try {
       if (self.useGlobal) {
@@ -114,14 +120,22 @@ function REPLServer(prompt, stream, eval_, useGlobal, ignoreUndefined) {
     } catch (e) {
       err = e;
     }
-    if (err && process.domain) {
+    if (err && process.domain && !isSyntaxError(err)) {
       process.domain.emit('error', err);
       process.domain.exit();
     }
     else {
       cb(err, result);
     }
-  };
+  }
+
+  self.eval = self._domain.bind(eval_);
+
+  self._domain.on('error', function(e) {
+    self.outputStream.write((e.stack || e) + '\n');
+    self.bufferedCommand = '';
+    self.displayPrompt();
+  });
 
   if (!input && !output) {
     // legacy API, passing a 'stream'/'socket' option
@@ -279,7 +293,7 @@ function REPLServer(prompt, stream, eval_, useGlobal, ignoreUndefined) {
         self.displayPrompt();
         return;
       } else if (e) {
-        self.outputStream.write((e.stack || e) + '\n');
+        self._domain.emit('error', e);
       }
 
       // Clear buffer if no SyntaxErrors

test/simple/test-repl-domain.js

@@ -19,6 +19,9 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+var assert = require('assert');
+var common = require('../common.js');
+
 var util   = require('util');
 var repl   = require('repl');
 

test/simple/test-repl-options.js

@@ -67,5 +67,4 @@ assert.equal(r2.rli.terminal, false);
 assert.equal(r2.useColors, true);
 assert.equal(r2.useGlobal, true);
 assert.equal(r2.ignoreUndefined, true);
-assert.equal(r2.eval, evaler);
 assert.equal(r2.writer, writer);

test/simple/test-repl-timeout-throw.js

@@ -0,0 +1,77 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+var assert = require('assert');
+var common = require('../common.js');
+
+var spawn = require('child_process').spawn;
+
+var child = spawn(process.execPath, [ '-i' ], {
+  stdio: [null, null, 2]
+});
+
+var stdout = '';
+child.stdout.setEncoding('utf8');
+child.stdout.on('data', function(c) {
+  process.stdout.write(c);
+  stdout += c;
+});
+
+child.stdin.write = function(original) { return function(c) {
+  process.stderr.write(c);
+  return original.call(child.stdin, c);
+}}(child.stdin.write);
+
+child.stdout.once('data', function() {
+  child.stdin.write('var throws = 0;');
+  child.stdin.write('process.on("exit",function(){console.log(throws)});');
+  child.stdin.write('function thrower(){console.log("THROW",throws++);XXX};');
+  child.stdin.write('setTimeout(thrower);""\n');
+
+  setTimeout(fsTest, 50);
+  function fsTest() {
+    var f = JSON.stringify(__filename);
+    child.stdin.write('fs.readFile(' + f + ', thrower);\n');
+    setTimeout(eeTest, 50);
+  }
+
+  function eeTest() {
+    child.stdin.write('setTimeout(function() {\n' +
+                      '  var events = require("events");\n' +
+                      '  var e = new events.EventEmitter;\n' +
+                      '  process.nextTick(function() {\n' +
+                      '    e.on("x", thrower);\n' +
+                      '    setTimeout(function() {\n' +
+                      '      e.emit("x");\n' +
+                      '    });\n' +
+                      '  });\n' +
+                      '});"";\n');
+
+    setTimeout(child.stdin.end.bind(child.stdin), 50);
+  }
+});
+
+child.on('exit', function(c) {
+  assert(!c);
+  // make sure we got 3 throws, in the end.
+  var lastLine = stdout.trim().split(/\r?\n/).pop();
+  assert.equal(lastLine, '> 3');
+});