repl: make 'Unexpected token' errors recoverable

Fix the regexp used to detect 'Unexpected token' errors so that they can
be considered as recoverable. This fixes the following use case:

> var foo = 'bar \
... baz';
undefined
> foo
'bar baz'
>

Fixes: nodejs/node-v0.x-archive#8874
PR-URL: nodejs/node-v0.x-archive#8875
PR-URL: nodejs#2052
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Ben Noordhuis <[email protected]>

lib/repl.js

@@ -994,7 +994,7 @@ function isRecoverableError(e, self) {
       self._inTemplateLiteral = true;
       return true;
     }
-    return /^(Unexpected end of input|Unexpected token :)/.test(message);
+    return /^(Unexpected end of input|Unexpected token)/.test(message);
   }
   return false;
 }

test/parallel/test-repl-unexpected-token-recoverable.js

@@ -0,0 +1,33 @@
+'use strict';
+/*
+ * This is a regression test for https://github.com/joyent/node/issues/8874.
+ */
+var common = require('../common');
+var assert = require('assert');
+
+var spawn = require('child_process').spawn;
+// use -i to force node into interactive mode, despite stdout not being a TTY
+var args = [ '-i' ];
+var child = spawn(process.execPath, args);
+
+var input = 'var foo = "bar\\\nbaz"';
+// Match '...' as well since it marks a multi-line statement
+var expectOut = /^> ... undefined\n/;
+
+child.stderr.setEncoding('utf8');
+child.stderr.on('data', function(c) {
+  throw new Error('child.stderr be silent');
+});
+
+child.stdout.setEncoding('utf8');
+var out = '';
+child.stdout.on('data', function(c) {
+  out += c;
+});
+
+child.stdout.on('end', function() {
+  assert(expectOut.test(out));
+  console.log('ok');
+});
+
+child.stdin.end(input);