use babylon instead of espree to support more experimental features. …

…see #398

lib/cli.js

@@ -109,9 +109,17 @@ function logError(e) {
   var msg = typeof e === 'string' ? e : e.message;
 
   // esprima.parse errors are in the format 'Line 123: Unexpected token &'
+  // we support both formats since users might replace the parser
   if ((/Line \d+:/).test(msg)) {
     // convert into "Error: <filepath>:<line> <error_message>"
     msg = 'Error: ' + msg.replace(/[^\d]+(\d+): (.+)/, e.file + ':$1 $2');
+  } else {
+    // babylon.parse errors are in the format 'Unexpected token (0:4)'
+    var m = (/^([^\(]+)\s\((\d+):(\d+)\)/).exec(msg);
+    if (m) {
+      // convert into "Error: <filepath>:<line>:<char> <error_message>"
+      msg = 'Error: ' + e.file + ':' + m[2] + ':' + m[3] + ' ' + m[1];
+    }
   }
 
   // set the error flag to true to use an exit code !== 0

lib/format.js

@@ -1,14 +1,22 @@
 'use strict';
 
 var _options = require('./options');
-// we use espree because it supports more ES6 features than esprima at the
-// moment and supports JSX
-var espree = require('espree');
+
+// we use babylon because it supports more ES6+ features than esprima at the
+// moment and also supports JSX
+var acornToEsprima = require('acorn-to-esprima');
+var babelTraverse = require('babel-traverse').default;
+var babylon = require('babylon');
 var npmRun = require('npm-run');
 var plugins = require('./plugins');
 var rocambole = require('rocambole');
 var transform = require('./transform');
 
+// need to skip extra properties from babylon otherwise we would format more
+// nodes than we need and it also confuses rocambole about {start|end}Token
+rocambole.BYPASS_RECURSION.loc = true;
+rocambole.BYPASS_RECURSION.leadingComments = true;
+rocambole.BYPASS_RECURSION.trailingComments = true;
 
 exports = module.exports = format;
 function format(str, opts) {
@@ -18,13 +26,14 @@ function format(str, opts) {
 
   // remove shebang before pipe because piped commands might not know how
   // to handle it
-  var prefix = '';
-  if (_options.get('esformatter.allowShebang')) {
-    prefix = getShebang(str);
-    if (prefix) {
-      str = str.replace(prefix, '');
-    }
+  var prefix = getShebang(str);
+  if (prefix && !_options.get('esformatter.allowShebang')) {
+    throw new Error(
+      'shebang not allowed! Set esformatter.allowShebang to true if you ' +
+       'want to support it.'
+    );
   }
+  str = str.replace(prefix, '');
 
   var pipeCommands = _options.get('pipe');
 
@@ -44,35 +53,65 @@ function format(str, opts) {
 }
 
 
-// allows users to override parser
-exports.parseFn = espree.parse;
-exports.parseContext = espree;
+// allows users to override parser if needed
+exports.parseFn = function(str, opts) {
+  var ast = babylon.parse(str, opts);
+
+  // remove EOF token, eslint doesn't use this for anything and it interferes with some rules
+  // see https://github.com/babel/babel-eslint/issues/2 for more info
+  // todo: find a more elegant way to do this
+  ast.tokens.pop();
+
+  // convert tokens
+  ast.tokens = acornToEsprima.toTokens(ast.tokens, babylon.tokTypes, str);
+
+  // add comments
+  acornToEsprima.convertComments(ast.comments);
+
+  // transform esprima and acorn divergent nodes
+  acornToEsprima.toAST(ast, babelTraverse, str);
+
+  // remove File
+  ast.type = 'Program';
+  ast.sourceType = ast.program.sourceType;
+  ast.directives = ast.program.directives;
+  ast.body = ast.program.body;
+  delete ast.program;
+  delete ast._paths;
+
+  acornToEsprima.attachComments(ast, ast.comments, ast.tokens);
+
+  return ast;
+};
+
+exports.parseContext = null;
+
 exports.parseOptions = {
-  ecmaFeatures: {
-    arrowFunctions: true,
-    blockBindings: true,
-    destructuring: true,
-    regexYFlag: true,
-    regexUFlag: true,
-    templateStrings: true,
-    binaryLiterals: true,
-    octalLiterals: true,
-    unicodeCodePointEscapes: true,
-    defaultParams: true,
-    restParams: true,
-    forOf: true,
-    objectLiteralComputedProperties: true,
-    objectLiteralShorthandMethods: true,
-    objectLiteralShorthandProperties: true,
-    objectLiteralDuplicateProperties: true,
-    generators: true,
-    spread: true,
-    classes: true,
-    modules: true,
-    jsx: true,
-    globalReturn: true,
-    experimentalObjectRestSpread: true
-  }
+  allowImportExportEverywhere: false, // consistent with espree
+  allowReturnOutsideFunction: true,
+  allowSuperOutsideMethod: true,
+  locations: true,
+  onComment: [],
+  onToken: [],
+  plugins: [
+    'asyncFunctions',
+    'asyncGenerators',
+    'classConstructorCall',
+    'classProperties',
+    'decorators',
+    'doExpressions',
+    'exponentiationOperator',
+    'exportExtensions',
+    'flow',
+    'functionBind',
+    'functionSent',
+    'jsx',
+    'objectRestSpread',
+    'trailingFunctionCommas'
+  ],
+  ranges: true,
+  sourceType: 'module',
+  strictMode: true
 };
 
 

package.json

@@ -46,9 +46,11 @@
     "mockery": "^1.4.0"
   },
   "dependencies": {
+    "acorn-to-esprima": "^2.0.6",
+    "babel-traverse": "^6.4.5",
+    "babylon": "^6.4.5",
     "debug": "^0.7.4",
     "disparity": "^2.0.0",
-    "espree": "^2.2.4",
     "glob": "^5.0.3",
     "minimist": "^1.1.1",
     "mout": ">=0.9 <2.0",

test/cli.spec.js

@@ -221,8 +221,8 @@ describe('Command line interface', function() {
     // using match because of absolute path and also because file order might
     // be different in some OS. we just make sure that error message contains
     // what we expect to find
-    expect(msg).to.match(/Error: .+invalid-1.js:4 Unexpected token &/);
-    expect(msg).to.match(/Error: .+invalid-2.js:3 Invalid regular expression/);
+    expect(msg).to.match(/Error: .+invalid-1.js:4:0 Unexpected token/);
+    expect(msg).to.match(/Error: .+invalid-2.js:3:9 Invalid regular expression/);
   });
 
 });

test/compare/error/invalid-2.js

@@ -1,6 +1,6 @@
 
 // invalid RegExp
-var r = /[\u{61}-b]/u;
+var r = /[\u{61}-b]/ugetqweasdasdlk;
 
 // some random invalid tokens
 $%899

test/format.spec.js

@@ -2,7 +2,7 @@
 /*global describe:false, it:false*/
 "use strict";
 
-var espree = require('espree');
+var babylon = require('babylon');
 var expect = require('chai').expect;
 var _glob = require('glob');
 var _path = require('path');
@@ -42,7 +42,7 @@ describe('esformatter.format()', function() {
         // result should be valid JS
         expect(function() {
           try {
-            espree.parse(result, esformatter.format.parseOptions);
+            babylon.parse(result, esformatter.format.parseOptions);
           } catch (e) {
             throw new Error('esformatter.format() result produced a non-valid output.\n' + e);
           }
@@ -78,7 +78,7 @@ describe('esformatter.format()', function() {
         // result should be valid JS
         expect(function() {
           try {
-            espree.parse(result, esformatter.format.parseOptions);
+            babylon.parse(result, esformatter.format.parseOptions);
           } catch (e) {
             throw new Error('esformatter.format() result produced a non-valid output.\n' + e);
           }
@@ -113,7 +113,7 @@ describe('esformatter.format()', function() {
         // result should be valid JS
         expect(function() {
           try {
-            espree.parse(result, esformatter.format.parseOptions);
+            babylon.parse(result, esformatter.format.parseOptions);
           } catch (e) {
             throw new Error('esformatter.format() result produced a non-valid output.\n' + e);
           }