Improved parser error messages

lib/coffee-script/coffee-script.js

@@ -1,6 +1,6 @@
 // Generated by CoffeeScript 1.5.0
 (function() {
-  var Lexer, compile, ext, extensions, fs, lexer, loadFile, parser, path, vm, _i, _len,
+  var CompilerError, Lexer, compile, ext, extensions, fs, lexer, loadFile, parser, path, vm, _i, _len,
     __indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; },
     __hasProp = {}.hasOwnProperty;
 
@@ -12,6 +12,8 @@
 
   parser = require('./parser').parser;
 
+  CompilerError = require('./error').CompilerError;
+
   vm = require('vm');
 
   extensions = ['.coffee', '.litcoffee'];
@@ -173,4 +175,12 @@
 
   parser.yy = require('./nodes');
 
+  parser.yy.parseError = function(message, _arg) {
+    var first_column, first_line, last_column, last_line, loc, token;
+    loc = _arg.loc, token = _arg.token;
+    message = "unexpected " + token;
+    first_line = loc.first_line, first_column = loc.first_column, last_line = loc.last_line, last_column = loc.last_column;
+    throw new CompilerError(message, first_line + 1, first_column + 1, last_line + 1, last_column + 1);
+  };
+
 }).call(this);

lib/coffee-script/error.js

@@ -25,7 +25,7 @@
 
     CompilerError.prototype.prettyMessage = function(fileName, code) {
       var errorLength, errorLine, marker, message;
-      message = "" + fileName + ":" + this.startLine + ":" + this.startColumn + ": " + this.message;
+      message = "" + fileName + ":" + this.startLine + ":" + this.startColumn + ": error: " + this.message;
       if (this.startLine === this.endLine) {
         errorLine = code.split('\n')[this.startLine - 1];
         errorLength = this.endColumn - this.startColumn + 1;

src/coffee-script.coffee

@@ -6,11 +6,12 @@
 # If included on a webpage, it will automatically sniff out, compile, and
 # execute all scripts present in `text/coffeescript` tags.
 
-fs        = require 'fs'
+fs              = require 'fs'
-path      = require 'path'
+path            = require 'path'
-{Lexer}   = require './lexer'
+{Lexer}         = require './lexer'
-{parser}  = require './parser'
+{parser}        = require './parser'
-vm        = require 'vm'
+{CompilerError} = require './error'
+vm              = require 'vm'
 
 # The file extensions that are considered to be CoffeeScript.
 extensions = ['.coffee', '.litcoffee']
@@ -135,4 +136,13 @@ parser.lexer =
   upcomingInput: ->
     ""
 
+# Make all the AST nodes visible to the parser.
 parser.yy = require './nodes'
+
+# Override Jison's default error handling function.
+parser.yy.parseError = (message, {loc, token}) ->
+  # Disregard Jison's message, it contains redundant line numer information.
+  message = "unexpected #{token}"
+
+  {first_line, first_column, last_line, last_column} = loc
+  throw new CompilerError message, first_line + 1, first_column + 1, last_line + 1, last_column + 1

src/error.coffee

@@ -15,7 +15,7 @@ exports.CompilerError = class CompilerError extends Error
   # showing where the error is.
   # TODO: tests
   prettyMessage: (fileName, code) ->
-    message = "#{fileName}:#{@startLine}:#{@startColumn}: #{@message}"
+    message = "#{fileName}:#{@startLine}:#{@startColumn}: error: #{@message}"
     if @startLine is @endLine
       errorLine = code.split('\n')[@startLine - 1]
       errorLength = @endColumn - @startColumn + 1