Make the REPL use the global context to be consistent with the node REPL.

This will make packages that modify prototypes - e.g. 'colors', 'sugar'
- work as expected.

To verify that the `node` REPL uses the global context, execute `global
=== module.exports.repl.context`.

Note: Tests pass, except `cluster.coffee`, which, however, failed even
before these modifications.

lib/coffee-script/repl.js

@@ -18,6 +18,7 @@
     prompt: 'coffee> ',
     historyFile: process.env.HOME ? path.join(process.env.HOME, '.coffee_history') : void 0,
     historyMaxInputSize: 10240,
+    useGlobal: true,
     "eval": function(input, context, filename, cb) {
       var Assign, Block, Literal, Value, ast, err, js, _ref1;
       input = input.replace(/\uFF00/g, '\n');
@@ -30,7 +31,7 @@
           bare: true,
           locals: Object.keys(context)
         });
-        return cb(null, vm.runInContext(js, context, filename));
+        return cb(null, context === global ? vm.runInThisContext(js, filename) : vm.runInContext(js, context, filename));
       } catch (_error) {
         err = _error;
         updateSyntaxError(err, input);

src/repl.coffee

@@ -9,6 +9,8 @@ replDefaults =
   prompt: 'coffee> ',
   historyFile: path.join process.env.HOME, '.coffee_history' if process.env.HOME
   historyMaxInputSize: 10240
+  # Make the REPL use the global context by default so as to (a) be consistent with the `node` REPL and, therefore, (b) make packages that modify prototypes - e.g., 'colors', 'sugar' - work as expected.
+  useGlobal: yes
   eval: (input, context, filename, cb) ->
     # XXX: multiline hack.
     input = input.replace /\uFF00/g, '\n'
@@ -27,7 +29,7 @@ replDefaults =
         new Assign (new Value new Literal '_'), ast, '='
       ]
       js = ast.compile bare: yes, locals: Object.keys(context)
-      cb null, vm.runInContext(js, context, filename)
+      cb null, if context is global then vm.runInThisContext(js, filename) else vm.runInContext(js, context, filename)
     catch err
       # AST's `compile` does not add source code information to syntax errors.
       updateSyntaxError err, input

test/repl.coffee

@@ -102,10 +102,11 @@ testRepl "existential assignment of previously declared variable", (input, outpu
   eq '42', output.lastWrite()
 
 testRepl "keeps running after runtime error", (input, output) ->
+  input.emitLine 'a = 0'  # Note: with the REPL option `useGlobal` set to true, variables are retained across tests.
   input.emitLine 'a = b'
   eq 0, output.lastWrite().indexOf 'ReferenceError: b is not defined'
   input.emitLine 'a'
-  eq 'undefined', output.lastWrite()
+  eq '0', output.lastWrite()
 
 process.on 'exit', ->
   fs.unlinkSync historyFile