v1.9.8

bin/6to5-node

@@ -41,9 +41,7 @@ var _eval = function (code, filename) {
 };
 
 if (commander.eval) {
-  var code = to5.transform(commander.eval, { filename: "eval" }).code;
-
-  var result = _eval(code, "eval");
+  var result = _eval(commander.eval, "eval");
   if (commander.print) console.log(result);
 } else {
   var filenames = commander.args;

bin/6to5/dir.js

@@ -13,7 +13,7 @@ module.exports = function (commander, filenames, opts) {
   var write = function (src, relative) {
     var dest = path.join(commander.outDir, relative);
 
-    var data = util.compile(src, dest);
+    var data = util.compile(src, { sourceMapName: dest });
 
     var up = path.normalize(dest + "/..");
     mkdirp.sync(up);

bin/6to5/file.js

@@ -100,8 +100,8 @@ module.exports = function (commander, filenames, opts) {
       }
     });
 
-    _.each(_filenames, function (filename) {
-      results.push(util.compile(filename));
+    _.each(_filenames, function (filename, i) {
+      results.push(util.compile(filename, { _noStrict: i != 0 }));
     });
 
     output();

bin/6to5/util.js

@@ -9,9 +9,9 @@ exports.readdirFilter = function (filename) {
   return readdir(filename).filter(util.canCompile);
 };
 
-exports.transform = function (filename, code, to) {
-  var opts = _.extend({ filename: filename }, index.opts);
-  if (to) opts.sourceMapName = to;
+exports.transform = function (filename, code, opts) {
+  opts = _.extend(opts || {}, index.opts);
+  opts.filename = filename;
 
   var result = to5.transform(code, opts);
   result.filename = filename;
@@ -19,7 +19,7 @@ exports.transform = function (filename, code, to) {
   return result;
 };
 
-exports.compile = function (filename, to) {
+exports.compile = function (filename, opts) {
   var code = fs.readFileSync(filename, "utf8");
-  return exports.transform(filename, code, to);
+  return exports.transform(filename, code, opts);
 };

lib/6to5/file.js

@@ -22,8 +22,7 @@ File.normaliseOptions = function (opts) {
     blacklist: [],
     whitelist: [],
     sourceMap: false,
-    filename:  "unknown",
-    format:    {}
+    filename:  "unknown"
   });
 
   _.defaults(opts, {
@@ -80,14 +79,6 @@ File.prototype.transform = function (ast) {
     transformer.transform(self);
   });
 
-  var body = ast.program.body;
-
-  _.each(this.declarations, function (declar) {
-    body.unshift(b.variableDeclaration("var", [
-      b.variableDeclarator(declar.uid, declar.node)
-    ]));
-  });
-
   return this.generate();
 };
 
@@ -95,7 +86,10 @@ File.prototype.generate = function () {
   var opts = this.opts;
   var ast  = this.ast;
 
-  var printOpts = {};
+  var printOpts = {
+    tabWidth: 2
+  };
+
   if (opts.sourceMap) {
     printOpts.sourceMapName = opts.sourceMapName;
   }

lib/6to5/transform.js

@@ -39,11 +39,13 @@ transform.test = function (task, assert) {
     var actualCode = actual.code.trim();
     var expectCode = expect.code.trim();
 
+    var printOpts = { tabWidth: 2 };
+
     result     = transform(actualCode, getOpts(actual.filename));
-    actualCode = recast.prettyPrint(result.ast).code;
+    actualCode = recast.prettyPrint(result.ast, printOpts).code;
 
     var expectAst    = util.parse(expect, expectCode);
-    var expectResult = recast.prettyPrint(expectAst);
+    var expectResult = recast.prettyPrint(expectAst, printOpts);
     expectCode       = expectResult.code;
 
     assert.equal(actualCode, expectCode);
@@ -98,7 +100,10 @@ transform.transformers = {
   jsx:                      require("./transformers/jsx"),
 
   _aliasFunctions:          require("./transformers/_alias-functions"),
-  _blockHoist:              require("./transformers/_block-hoist")
+  _blockHoist:              require("./transformers/_block-hoist"),
+  _declarations:            require("./transformers/_declarations"),
+
+  useStrict:                require("./transformers/use-strict")
 };
 
 _.each(transform.transformers, function (transformer, key) {

lib/6to5/transformer.js

@@ -13,6 +13,7 @@ Transformer.normalise = function (transformer) {
     transformer = { ast: transformer };
   } else {
     _.each(transformer, function (fns, type) {
+      if (type === "ast") return;
       if (_.isFunction(fns)) fns = { enter: fns };
       transformer[type] = fns;
     });
@@ -27,7 +28,7 @@ Transformer.prototype.transform = function (file) {
   var ast         = file.ast;
 
   if (transformer.ast) {
-    transformer.ast(ast);
+    transformer.ast(ast, file);
   }
 
   var build = function (exit) {
@@ -59,6 +60,8 @@ Transformer.prototype.transform = function (file) {
 };
 
 Transformer.prototype.canRun = function (file) {
+  if (this.key[0] === "_") return true;
+
   var opts = file.opts;
 
   var blacklist = opts.blacklist;

lib/6to5/transformers/_declarations.js

@@ -0,0 +1,12 @@
+var b = require("recast").types.builders;
+var _ = require("lodash");
+
+module.exports = function (ast, file) {
+  var body = ast.program.body;
+
+  _.each(file.declarations, function (declar) {
+    body.unshift(b.variableDeclaration("var", [
+      b.variableDeclarator(declar.uid, declar.node)
+    ]));
+  });
+};

lib/6to5/transformers/react.js

@@ -0,0 +1,63 @@
+var b = require("recast").types.builders;
+var _ = require("lodash");
+
+var addDisplayName = function (id, call) {
+  if (!call || call.type !== "CallExpression") return;
+
+  var callee = call.callee;
+  if (callee.type !== "MemberExpression") return;
+
+  // not React
+  var obj = callee.object;
+  if (obj.type !== "Identifier" || obj.name !== "React") return;
+
+  // not createClass
+  var prop = callee.property;
+  if (prop.type !== "Identifier" || prop.name !== "createClass") return;
+
+  // no arguments
+  var args = call.arguments;
+  if (args.length !== 1) return;
+
+  // not an object
+  var first = args[0];
+  if (first.type !== "ObjectExpression") return;
+
+  var props = first.properties;
+  var safe = true;
+
+  _.each(props, function (prop) {
+    if (prop.key.name === "displayName") {
+      return safe = false;
+    }
+  });
+
+  if (safe) {
+    props.unshift(b.property("init", b.identifier("displayName"), b.literal(id)));
+  }
+};
+
+exports.AssignmentExpression =
+exports.Property =
+exports.VariableDeclarator = function (node) {
+  var left, right;
+
+  if (node.type === "AssignmentExpression") {
+    left = node.left;
+    right = node.right;
+  } else if (node.type === "Property") {
+    left = node.key;
+    right = node.value;
+  } else if (node.type === "VariableDeclarator") {
+    left = node.id;
+    right = node.init;
+  }
+
+  if (left && left.type === "MemberExpression") {
+    left = left.property;
+  }
+
+  if (left && left.type === "Identifier") {
+    addDisplayName(left.name, right);
+  }
+};

lib/6to5/transformers/use-strict.js

@@ -0,0 +1,15 @@
+var b = require("recast").types.builders;
+
+module.exports = function (ast, file) {
+  var body = ast.program.body;
+  var first = body[0];
+
+  var noStrict = !first || first.type !== "ExpressionStatement" || first.expression.type !== "Literal" || first.expression.value !== "use strict";
+
+  if (noStrict) {
+    if (file.opts._noStrict) return;
+    body.unshift(b.expressionStatement(b.literal("use strict")));
+  } else {
+    if (file.opts._noStrict) body.shift();
+  }
+};

package.json

@@ -1,7 +1,7 @@
 {
   "name": "6to5",
   "description": "Turn ES6 code into readable vanilla ES5 with source maps",
-  "version": "1.9.7",
+  "version": "1.9.8",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://github.com/sebmck/6to5",
   "repository": {

test/fixtures/bin/6to5/--blacklist/stdout.txt

@@ -1 +1,2 @@
+"use strict";
 arr.map(x => x * MULTIPLIER);

test/fixtures/bin/6to5/dir --out-dir --source-maps-inline/out-files/lib/bar/bar.js

@@ -1,5 +1,7 @@
+"use strict";
+
 var Test = function() {
   var Test = function Test() {};
   return Test;
 }();
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoibGliL2Jhci9iYXIuanMiLCJzb3VyY2VzIjpbInNyYy9iYXIvYmFyLmpzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiJJQUFNLENBQUMsQ0FBQyxDQUFDO01BQUgsQ0FBQyxDQUFDLENBQUMsYUFBSCxDQUFDLENBQUMsQ0FBQztTQUFILENBQUMsQ0FBQyxDQUFDIiwic291cmNlc0NvbnRlbnQiOlsiY2xhc3MgVGVzdCB7XG5cbn0iXX0=
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoic3JjL2Jhci9iYXIuanMiLCJzb3VyY2VzIjpbInNyYy9iYXIvYmFyLmpzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7O0lBQU0sQ0FBQyxDQUFDLENBQUM7TUFBSCxDQUFDLENBQUMsQ0FBQyxhQUFILENBQUMsQ0FBQyxDQUFDO1NBQUgsQ0FBQyxDQUFDLENBQUMiLCJzb3VyY2VzQ29udGVudCI6WyJjbGFzcyBUZXN0IHtcblxufSJdfQ==

test/fixtures/bin/6to5/dir --out-dir --source-maps-inline/out-files/lib/foo.js

@@ -1,4 +1,5 @@
+"use strict";
 arr.map(function(x) {
   return x * MULTIPLIER;
 });
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoibGliL2Zvby5qcyIsInNvdXJjZXMiOlsic3JjL2Zvby5qcyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiQUFBQSxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLFVBQUM7U0FBSyxFQUFFLEVBQUUsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUM7Q0FBQyxDQUFDIiwic291cmNlc0NvbnRlbnQiOlsiYXJyLm1hcCh4ID0+IHggKiBNVUxUSVBMSUVSKTsiXX0=
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoic3JjL2Zvby5qcyIsInNvdXJjZXMiOlsic3JjL2Zvby5qcyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiO0FBQUEsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxVQUFDO1NBQUssRUFBRSxFQUFFLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDO0NBQUMsQ0FBQyIsInNvdXJjZXNDb250ZW50IjpbImFyci5tYXAoeCA9PiB4ICogTVVMVElQTElFUik7Il19

test/fixtures/bin/6to5/dir --out-dir --source-maps/out-files/lib/bar/bar.js

@@ -1,3 +1,5 @@
+"use strict";
+
 var Test = function() {
   var Test = function Test() {};
   return Test;

test/fixtures/bin/6to5/dir --out-dir --source-maps/out-files/lib/bar/bar.js.map

@@ -1 +1 @@
-{"version":3,"file":"lib/bar/bar.js","sources":["src/bar/bar.js"],"names":[],"mappings":"IAAM,CAAC,CAAC,CAAC;MAAH,CAAC,CAAC,CAAC,aAAH,CAAC,CAAC,CAAC;SAAH,CAAC,CAAC,CAAC","sourcesContent":["class Test {\n\n}"]}
+{"version":3,"file":"src/bar/bar.js","sources":["src/bar/bar.js"],"names":[],"mappings":";;IAAM,CAAC,CAAC,CAAC;MAAH,CAAC,CAAC,CAAC,aAAH,CAAC,CAAC,CAAC;SAAH,CAAC,CAAC,CAAC","sourcesContent":["class Test {\n\n}"]}

test/fixtures/bin/6to5/dir --out-dir --source-maps/out-files/lib/foo.js

@@ -1,3 +1,4 @@
+"use strict";
 arr.map(function(x) {
   return x * MULTIPLIER;
 });

test/fixtures/bin/6to5/dir --out-dir --source-maps/out-files/lib/foo.js.map

@@ -1 +1 @@
-{"version":3,"file":"lib/foo.js","sources":["src/foo.js"],"names":[],"mappings":"AAAA,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,UAAC;SAAK,EAAE,EAAE,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC;CAAC,CAAC","sourcesContent":["arr.map(x => x * MULTIPLIER);"]}
+{"version":3,"file":"src/foo.js","sources":["src/foo.js"],"names":[],"mappings":";AAAA,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,UAAC;SAAK,EAAE,EAAE,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC;CAAC,CAAC","sourcesContent":["arr.map(x => x * MULTIPLIER);"]}

test/fixtures/bin/6to5/dir --out-dir/out-files/lib/bar/bar.js

@@ -1,3 +1,5 @@
+"use strict";
+
 var Test = function() {
   var Test = function Test() {};
   return Test;

test/fixtures/bin/6to5/dir --out-dir/out-files/lib/foo.js

@@ -1,3 +1,4 @@
+"use strict";
 arr.map(function(x) {
   return x * MULTIPLIER;
 });

test/fixtures/bin/6to5/filename --out-file --source-maps-inline/out-files/script2.js

@@ -1,5 +1,6 @@
+"use strict";
 arr.map(function(x) {
   return x * MULTIPLIER;
 });
 
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNjcmlwdC5qcyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiQUFBQSxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLFVBQUM7U0FBSyxFQUFFLEVBQUUsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUM7Q0FBQyxDQUFDIiwiZmlsZSI6InNjcmlwdDIuanMiLCJzb3VyY2VzQ29udGVudCI6WyJhcnIubWFwKHggPT4geCAqIE1VTFRJUExJRVIpOyJdfQ==
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNjcmlwdC5qcyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiO0FBQUEsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxVQUFDO1NBQUssRUFBRSxFQUFFLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDO0NBQUMsQ0FBQyIsImZpbGUiOiJzY3JpcHQyLmpzIiwic291cmNlc0NvbnRlbnQiOlsiYXJyLm1hcCh4ID0+IHggKiBNVUxUSVBMSUVSKTsiXX0=

test/fixtures/bin/6to5/filename --out-file/out-files/script2.js

@@ -1,3 +1,4 @@
+"use strict";
 arr.map(function(x) {
   return x * MULTIPLIER;
 });

test/fixtures/bin/6to5/filenames --out-file --source-maps-inline/out-files/script3.js

@@ -1,3 +1,5 @@
+"use strict";
+
 var Test = function() {
   var Test = function Test() {};
   return Test;
@@ -6,4 +8,4 @@ arr.map(function(x) {
   return x * MULTIPLIER;
 });
 
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNjcmlwdC5qcyIsInNjcmlwdDIuanMiXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6IklBQU0sQ0FBQyxDQUFDLENBQUM7TUFBSCxDQUFDLENBQUMsQ0FBQyxhQUFILENBQUMsQ0FBQyxDQUFDO1NBQUgsQ0FBQyxDQUFDLENBQUM7OztBQ0FULENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsVUFBQztTQUFLLEVBQUUsRUFBRSxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQztDQUFDLENBQUMiLCJmaWxlIjoic2NyaXB0My5qcyIsInNvdXJjZXNDb250ZW50IjpbImNsYXNzIFRlc3Qge1xuXG59IiwiYXJyLm1hcCh4ID0+IHggKiBNVUxUSVBMSUVSKTsiXX0=
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNjcmlwdC5qcyIsInNjcmlwdDIuanMiXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6Ijs7SUFBTSxDQUFDLENBQUMsQ0FBQztNQUFILENBQUMsQ0FBQyxDQUFDLGFBQUgsQ0FBQyxDQUFDLENBQUM7U0FBSCxDQUFDLENBQUMsQ0FBQzs7O0FDQVQsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxVQUFDO1NBQUssRUFBRSxFQUFFLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDO0NBQUMsQ0FBQyIsImZpbGUiOiJzY3JpcHQzLmpzIiwic291cmNlc0NvbnRlbnQiOlsiY2xhc3MgVGVzdCB7XG5cbn0iLCJhcnIubWFwKHggPT4geCAqIE1VTFRJUExJRVIpOyJdfQ==

test/fixtures/bin/6to5/filenames --out-file --source-maps/out-files/script3.js

@@ -1,3 +1,5 @@
+"use strict";
+
 var Test = function() {
   var Test = function Test() {};
   return Test;

test/fixtures/bin/6to5/filenames --out-file --source-maps/out-files/script3.js.map

@@ -1 +1 @@
-{"version":3,"sources":["script.js","script2.js"],"names":[],"mappings":"IAAM,CAAC,CAAC,CAAC;MAAH,CAAC,CAAC,CAAC,aAAH,CAAC,CAAC,CAAC;SAAH,CAAC,CAAC,CAAC;;;ACAT,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,UAAC;SAAK,EAAE,EAAE,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC;CAAC,CAAC","file":"script3.js","sourcesContent":["class Test {\n\n}","arr.map(x => x * MULTIPLIER);"]}
+{"version":3,"sources":["script.js","script2.js"],"names":[],"mappings":";;IAAM,CAAC,CAAC,CAAC;MAAH,CAAC,CAAC,CAAC,aAAH,CAAC,CAAC,CAAC;SAAH,CAAC,CAAC,CAAC;;;ACAT,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,UAAC;SAAK,EAAE,EAAE,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC;CAAC,CAAC","file":"script3.js","sourcesContent":["class Test {\n\n}","arr.map(x => x * MULTIPLIER);"]}

test/fixtures/bin/6to5/filenames --out-file/out-files/script3.js

@@ -1,3 +1,5 @@
+"use strict";
+
 var Test = function() {
   var Test = function Test() {};
   return Test;

test/fixtures/bin/6to5/stdin --out-file --source-maps/out-files/test.js

@@ -1,3 +1,4 @@
+"use strict";
 arr.map(function(x) {
   return x * x;
 });

test/fixtures/bin/6to5/stdin --out-file --source-maps/out-files/test.js.map

@@ -1 +1 @@
-{"version":3,"sources":["stdin"],"names":[],"mappings":"AAAA,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,UAAC;SAAK,EAAE,EAAE;CAAC,CAAC","file":"test.js","sourcesContent":["arr.map(x => x * x);"]}
+{"version":3,"sources":["stdin"],"names":[],"mappings":";AAAA,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,UAAC;SAAK,EAAE,EAAE;CAAC,CAAC","file":"test.js","sourcesContent":["arr.map(x => x * x);"]}

test/fixtures/bin/6to5/stdin --out-file/out-files/script.js

@@ -1,3 +1,4 @@
+"use strict";
 arr.map(function(x) {
   return x * MULTIPLIER;
 });

test/fixtures/bin/6to5/stdin --source-maps-inline/stdout.txt

@@ -1,5 +1,6 @@
+"use strict";
 arr.map(function(x) {
   return x * x;
 });
 
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiJBQUFBLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsVUFBQztTQUFLLEVBQUUsRUFBRTtDQUFDLENBQUMiLCJmaWxlIjoic3Rkb3V0Iiwic291cmNlc0NvbnRlbnQiOlsiYXJyLm1hcCh4ID0+IHggKiB4KTsiXX0=
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7QUFBQSxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLFVBQUM7U0FBSyxFQUFFLEVBQUU7Q0FBQyxDQUFDIiwiZmlsZSI6InN0ZG91dCIsInNvdXJjZXNDb250ZW50IjpbImFyci5tYXAoeCA9PiB4ICogeCk7Il19

test/fixtures/bin/6to5/stdin/stdout.txt

@@ -1,3 +1,4 @@
+"use strict";
 arr.map(function(x) {
   return x * MULTIPLIER;
 });

test/fixtures/syntax/api/blacklist/actual.js

@@ -1,5 +1,5 @@
 class Test {
   constructor() {
-    arr.map(x => x * x);
+  arr.map(x => x * x);
   }
 }

test/fixtures/syntax/api/blacklist/expected.js

@@ -1,6 +1,9 @@
-var Test = function () {
+"use strict";
+
+var Test = function() {
   var Test = function Test() {
     arr.map(x => x * x);
   };
+
   return Test;
-}();
+}();

test/fixtures/syntax/api/whitelist/actual.js

@@ -1,5 +1,5 @@
 class Test {
   constructor() {
-    arr.map(x => x * x);
+  arr.map(x => x * x);
   }
 }

test/fixtures/syntax/api/whitelist/expected.js

@@ -1,6 +1,6 @@
 class Test {
   constructor() {
-    arr.map(function (x) {
+    arr.map(function(x) {
       return x * x;
     });
   }

test/fixtures/syntax/array-comprehension/arguments/expected.js

@@ -1,8 +1,11 @@
+"use strict";
+
 function add() {
   var _arguments = arguments;
-  return [1, 2, 3].map(function (i) {
+
+  return [1, 2, 3].map(function(i) {
     return i * _arguments[0];
   });
 }
 
-add(5);
+add(5);

test/fixtures/syntax/array-comprehension/multiple-if/expected.js

@@ -1,7 +1,10 @@
-var seattlers = function () {
+"use strict";
+
+var seattlers = function() {
   var _arr = [];
-  countries.forEach(function (customers) {
-    customers.forEach(function (c) {
+
+  countries.forEach(function(customers) {
+    customers.forEach(function(c) {
       if (c.city == "Seattle") {
         _arr.push({
           name: c.name,
@@ -10,5 +13,6 @@ var seattlers = function () {
       }
     });
   });
+
   return _arr;
-}();
+}();

test/fixtures/syntax/array-comprehension/multiple/expected.js

@@ -1,11 +1,13 @@
-var arr = (function () {
+"use strict";
+
+var arr = function() {
   var _arr = [];
 
-  "abcdefgh".split("").forEach(function (x) {
-    "12345678".split("").forEach(function (y) {
+  "abcdefgh".split("").forEach(function(x) {
+    "12345678".split("").forEach(function(y) {
       _arr.push(x + y);
     });
   });
 
   return _arr;
-})();
+}();

test/fixtures/syntax/array-comprehension/single-if/expected.js

@@ -1,8 +1,10 @@
-var seattlers = customers.filter(function (c) {
+"use strict";
+
+var seattlers = customers.filter(function(c) {
   return c.city == "Seattle";
-}).map(function (c) {
+}).map(function(c) {
   return {
     name: c.name,
     age: c.age
   };
-});
+});

test/fixtures/syntax/array-comprehension/single/expected.js

@@ -1,3 +1,5 @@
-var arr = [1, 2, 3].map(function (i) {
+"use strict";
+
+var arr = [1, 2, 3].map(function(i) {
   return i * i;
-});
+});

test/fixtures/syntax/array-comprehension/this/expected.js

@@ -1,8 +1,13 @@
+"use strict";
+
 function add() {
   var _this = this;
-  return [1, 2, 3].map(function (i) {
+
+  return [1, 2, 3].map(function(i) {
     return i * _this.multiplier;
   });
 }
 
-add.call({ multiplier: 5 });
+add.call({
+  multiplier: 5
+});

test/fixtures/syntax/arrow-functions/arguments/actual.js

@@ -8,7 +8,7 @@ function two() {
   var inner = () => arguments;
 
   var another = function () {
-    var inner2 = () => arguments;
+  var inner2 = () => arguments;
   };
 
   return [].slice.call(inner());
@@ -35,10 +35,10 @@ five({ arguments: ["foo"] });
 
 function six(obj) {
   var fn = () => {
-    var fn2 = function () {
-      return arguments[0];
-    };
-    return fn2("foobar");
+  var fn2 = function () {
+    return arguments[0];
+  };
+  return fn2("foobar");
   };
   return fn();
 }

test/fixtures/syntax/arrow-functions/arguments/expected.js

@@ -1,56 +1,85 @@
+"use strict";
+
 function one() {
   var _arguments = arguments;
-  var inner = function () { return _arguments; };
+
+  var inner = function() {
+    return _arguments;
+  };
+
   return [].slice.call(inner());
 }
+
 one(1, 2);
 
 function two() {
   var _arguments2 = arguments;
-  var inner = function () { return _arguments2; };
 
-  var another = function () {
+  var inner = function() {
+    return _arguments2;
+  };
+
+  var another = function() {
     var _arguments3 = arguments;
-    var inner2 = function () { return _arguments3; };
+
+    var inner2 = function() {
+      return _arguments3;
+    };
   };
 
   return [].slice.call(inner());
 }
+
 two(1, 2);
 
 function three() {
   var _arguments4 = arguments;
-  var fn = function () {
+
+  var fn = function() {
     return _arguments4[0] + "bar";
   };
+
   return fn();
 }
+
 three("foo");
 
 function four() {
   var _arguments5 = arguments;
-  var fn = function () {
+
+  var fn = function() {
     return _arguments5[0].foo + "bar";
   };
+
   return fn();
 }
-four({ foo: "foo" });
+
+four({
+  foo: "foo"
+});
 
 function five(obj) {
-  var fn = function () {
+  var fn = function() {
     return obj.arguments[0].foo + "bar";
   };
+
   return fn();
 }
-five({ arguments: ["foo"] });
+
+five({
+  arguments: ["foo"]
+});
 
 function six(obj) {
-  var fn = function () {
-    var fn2 = function () {
+  var fn = function() {
+    var fn2 = function() {
       return arguments[0];
     };
+
     return fn2("foobar");
   };
+
   return fn();
 }
-six();
+
+six();

test/fixtures/syntax/arrow-functions/empty-arguments/expected.js

@@ -1,3 +1,5 @@
-var t = function () {
+"use strict";
+
+var t = function() {
   return 5 + 5;
-};
+};

test/fixtures/syntax/arrow-functions/empty-block/expected.js

@@ -1,2 +1,2 @@
-var t = function () {
-};
+"use strict";
+var t = function() {};

test/fixtures/syntax/arrow-functions/expression/expected.js

@@ -1,3 +1,5 @@
-arr.map(function (x) {
+"use strict";
+
+arr.map(function(x) {
   return x * x;
-});
+});

test/fixtures/syntax/arrow-functions/inside-call/expected.js

@@ -1,3 +1,5 @@
-arr.map(function (i) {
+"use strict";
+
+arr.map(function(i) {
   return i + 1;
-});
+});

test/fixtures/syntax/arrow-functions/multiple-arguments/expected.js

@@ -1,3 +1,5 @@
-var t = function (i, x) {
+"use strict";
+
+var t = function(i, x) {
   return i * x;
-};
+};

test/fixtures/syntax/arrow-functions/nested/actual.js

@@ -1,13 +1,13 @@
 module.exports = {
   init() {
-    return new Promise((resolve, reject) => {
-      MongoClient.connect(config.mongodb, (err, db) => {
-        if (err) {
-          return reject(err);
-        }
-        this.db = db;
-        resolve(this);
-      });
+  return new Promise((resolve, reject) => {
+    MongoClient.connect(config.mongodb, (err, db) => {
+    if (err) {
+      return reject(err);
+    }
+    this.db = db;
+    resolve(this);
     });
+  });
   }
 };

test/fixtures/syntax/arrow-functions/nested/expected.js

@@ -1,14 +1,18 @@
+"use strict";
+
 module.exports = {
   init: function() {
     var _this = this;
+
     return new Promise(function(resolve, reject) {
       MongoClient.connect(config.mongodb, function(err, db) {
         if (err) {
           return reject(err);
         }
+
         _this.db = db;
         resolve(_this);
       });
     });
   }
-};
+};

test/fixtures/syntax/arrow-functions/paran-insertion/expected.js

@@ -1,3 +1,5 @@
-var t = function (i) {
+"use strict";
+
+var t = function(i) {
   return i * 5;
-};
+};

test/fixtures/syntax/arrow-functions/single-argument/expected.js

@@ -1,3 +1,5 @@
-var t = function (i) {
+"use strict";
+
+var t = function(i) {
   return i * 5;
-};
+};

test/fixtures/syntax/arrow-functions/statement/actual.js

@@ -1,5 +1,5 @@
 nums.forEach(v => {
   if (v % 5 === 0) {
-    fives.push(v);
+  fives.push(v);
   }
 });

test/fixtures/syntax/arrow-functions/statement/expected.js

@@ -1,5 +1,7 @@
-nums.forEach(function (v) {
+"use strict";
+
+nums.forEach(function(v) {
   if (v % 5 === 0) {
     fives.push(v);
   }
-});
+});

test/fixtures/syntax/arrow-functions/this/expected.js

@@ -1,4 +1,6 @@
+"use strict";
 var _this = this;
-var t = function (x) {
+
+var t = function(x) {
   return _this.x + x;
-};
+};

test/fixtures/syntax/classes/accessing-super-class/actual.js

@@ -1,26 +1,26 @@
 class Test extends Foo {
   constructor() {
-    woops.super.test();
-    super();
-    super.test();
-    foob(super);
+  woops.super.test();
+  super();
+  super.test();
+  foob(super);
 
-    super(...arguments);
-    super("test", ...arguments);
+  super(...arguments);
+  super("test", ...arguments);
 
-    super.test(...arguments);
-    super.test("test", ...arguments);
+  super.test(...arguments);
+  super.test("test", ...arguments);
   }
 
   test() {
-    super();
-    super(...arguments);
-    super("test", ...arguments);
+  super();
+  super(...arguments);
+  super("test", ...arguments);
   }
 
   static foo() {
-    super();
-    super(...arguments);
-    super("test", ...arguments);
+  super();
+  super(...arguments);
+  super("test", ...arguments);
   }
 }

test/fixtures/syntax/classes/accessing-super-class/expected.js

@@ -1,3 +1,4 @@
+"use strict";
 var _slice = Array.prototype.slice;
 
 var Test = function(Foo) {
@@ -9,11 +10,7 @@ var Test = function(Foo) {
     Foo.call.apply(Foo, [this].concat(_slice.call(arguments)));
     Foo.call.apply(Foo, [this, "test"].concat(_slice.call(arguments)));
     Foo.prototype.test.call.apply(Foo.prototype, [this].concat(_slice.call(arguments)));
-
-    Foo.prototype.test.call.apply(
-      Foo.prototype,
-      [this, "test"].concat(_slice.call(arguments))
-    );
+    Foo.prototype.test.call.apply(Foo.prototype, [this, "test"].concat(_slice.call(arguments)));
   };
 
   Test.prototype = Object.create(Foo.prototype, {
@@ -34,11 +31,7 @@ var Test = function(Foo) {
       value: function() {
         Foo.prototype.test.call(this);
         Foo.prototype.test.call.apply(Foo.prototype.test, [this].concat(_slice.call(arguments)));
-
-        Foo.prototype.test.call.apply(
-          Foo.prototype.test,
-          [this, "test"].concat(_slice.call(arguments))
-        );
+        Foo.prototype.test.call.apply(Foo.prototype.test, [this, "test"].concat(_slice.call(arguments)));
       }
     }
   });
@@ -56,4 +49,4 @@ var Test = function(Foo) {
   });
 
   return Test;
-}(Foo);
+}(Foo);

test/fixtures/syntax/classes/accessing-super-properties/actual.js

@@ -1,6 +1,6 @@
 class Test extends Foo {
   constructor() {
-    super.test;
-    super.test.whatever;
+  super.test;
+  super.test.whatever;
   }
 }

test/fixtures/syntax/classes/accessing-super-properties/expected.js

@@ -1,3 +1,5 @@
+"use strict";
+
 var Test = function(Foo) {
   var Test = function Test() {
     Foo.prototype.test;
@@ -15,4 +17,4 @@ var Test = function(Foo) {
 
   Test.__proto__ = Foo;
   return Test;
-}(Foo);
+}(Foo);

test/fixtures/syntax/classes/calling-super-properties/actual.js

@@ -1,10 +1,10 @@
 class Test extends Foo {
   constructor() {
-    super.test.whatever();
-    super.test();
+  super.test.whatever();
+  super.test();
   }
 
   static test() {
-    return super.wow();
+  return super.wow();
   }
 }

test/fixtures/syntax/classes/calling-super-properties/expected.js

@@ -1,8 +1,11 @@
+"use strict";
+
 var Test = function(Foo) {
   var Test = function Test() {
     Foo.prototype.test.whatever();
     Foo.prototype.test.call(this);
   };
+
   Test.prototype = Object.create(Foo.prototype, {
     constructor: {
       value: Test,
@@ -11,7 +14,9 @@ var Test = function(Foo) {
       configurable: true
     }
   });
+
   Test.__proto__ = Foo;
+
   Object.defineProperties(Test, {
     test: {
       writable: true,
@@ -21,5 +26,6 @@ var Test = function(Foo) {
       }
     }
   });
+
   return Test;
-}(Foo);
+}(Foo);

test/fixtures/syntax/classes/constructor/actual.js

@@ -1,11 +1,11 @@
 class Test {
   constructor() {
-    this.state = "test";
+  this.state = "test";
   }
 }
 
 class Foo extends Bar {
   constructor() {
-    this.state = "test";
+  this.state = "test";
   }
 }

test/fixtures/syntax/classes/constructor/expected.js

@@ -1,7 +1,10 @@
-var Test = function () {
+"use strict";
+
+var Test = function() {
   var Test = function Test() {
     this.state = "test";
   };
+
   return Test;
 }();
 
@@ -21,4 +24,4 @@ var Foo = function(Bar) {
 
   Foo.__proto__ = Bar;
   return Foo;
-}(Bar);
+}(Bar);

test/fixtures/syntax/classes/instance-getter-and-setter/actual.js

@@ -1,8 +1,8 @@
 class Test {
   get test() {
-    return 5 + 5;
+  return 5 + 5;
   }
   set test(val) {
-    this._test = val;
+  this._test = val;
   }
 }

test/fixtures/syntax/classes/instance-getter-and-setter/expected.js

@@ -1,14 +1,19 @@
-var Test = function () {
-  var Test = function Test() { };
+"use strict";
+
+var Test = function() {
+  var Test = function Test() {};
+
   Object.defineProperties(Test.prototype, {
     test: {
-      get: function () {
+      get: function() {
         return 5 + 5;
       },
-      set: function (val) {
+
+      set: function(val) {
         this._test = val;
       }
     }
   });
+
   return Test;
-}();
+}();

test/fixtures/syntax/classes/instance-getter/actual.js

@@ -1,5 +1,5 @@
 class Test {
   get test() {
-    return 5 + 5;
+  return 5 + 5;
   }
 }

test/fixtures/syntax/classes/instance-getter/expected.js

@@ -1,11 +1,15 @@
-var Test = function () {
-  var Test = function Test() { };
+"use strict";
+
+var Test = function() {
+  var Test = function Test() {};
+
   Object.defineProperties(Test.prototype, {
     test: {
-      get: function () {
+      get: function() {
         return 5 + 5;
       }
     }
   });
+
   return Test;
-}();
+}();

test/fixtures/syntax/classes/instance-method/actual.js

@@ -1,5 +1,5 @@
 class Test {
   test() {
-    return 5 + 5;
+  return 5 + 5;
   }
 }

test/fixtures/syntax/classes/instance-method/expected.js

@@ -1,12 +1,17 @@
-var Test = function () {
-  var Test = function Test() { };
+"use strict";
+
+var Test = function() {
+  var Test = function Test() {};
+
   Object.defineProperties(Test.prototype, {
     test: {
       writable: true,
-      value: function () {
+
+      value: function() {
         return 5 + 5;
       }
     }
   });
+
   return Test;
-}();
+}();

test/fixtures/syntax/classes/instance-setter/actual.js

@@ -1,5 +1,5 @@
 class Test {
   set test(val) {
-    this._test = val;
+  this._test = val;
   }
 }

test/fixtures/syntax/classes/instance-setter/expected.js

@@ -1,11 +1,15 @@
-var Test = function () {
-  var Test = function Test() { };
+"use strict";
+
+var Test = function() {
+  var Test = function Test() {};
+
   Object.defineProperties(Test.prototype, {
     test: {
-      set: function (val) {
+      set: function(val) {
         this._test = val;
       }
     }
   });
+
   return Test;
-}();
+}();

test/fixtures/syntax/classes/plain-class/expected.js

@@ -1,4 +1,6 @@
-var Test = function () {
-  var Test = function Test() { };
+"use strict";
+
+var Test = function() {
+  var Test = function Test() {};
   return Test;
-}();
+}();

test/fixtures/syntax/classes/statement/actual.js

@@ -1,11 +1,11 @@
 var BaseView = class BaseView {
   constructor() {
-    this.autoRender = true;
+  this.autoRender = true;
   }
 }
 
 var BaseView = class {
   constructor() {
-    this.autoRender = true;
+  this.autoRender = true;
   }
 }

test/fixtures/syntax/classes/statement/expected.js

@@ -1,4 +1,6 @@
-var BaseView = function () {
+"use strict";
+
+var BaseView = function() {
   var BaseView = function BaseView() {
     this.autoRender = true;
   };
@@ -6,9 +8,10 @@ var BaseView = function () {
   return BaseView;
 }();
 
-var BaseView = function () {
-  var _class = function () {
+var BaseView = function() {
+  var _class = function() {
     this.autoRender = true;
   };
+
   return _class;
-}();
+}();

test/fixtures/syntax/classes/static/expected.js

@@ -1,3 +1,5 @@
+"use strict";
+
 var A = function() {
   var A = function A() {};
 
@@ -14,4 +16,4 @@ var A = function() {
   });
 
   return A;
-}();
+}();

test/fixtures/syntax/classes/super-class-id-member-expression/expected.js

@@ -1,7 +1,10 @@
-var BaseController = function (Chaplin) {
+"use strict";
+
+var BaseController = function(Chaplin) {
   var BaseController = function BaseController() {
     Chaplin.Controller.apply(this, arguments);
   };
+
   BaseController.prototype = Object.create(Chaplin.Controller.prototype, {
     constructor: {
       value: BaseController,
@@ -10,14 +13,16 @@ var BaseController = function (Chaplin) {
       configurable: true
     }
   });
+
   BaseController.__proto__ = Chaplin.Controller;
   return BaseController;
 }(Chaplin);
 
-var BaseController2 = function (Chaplin) {
+var BaseController2 = function(Chaplin) {
   var BaseController2 = function BaseController2() {
     Chaplin.Controller.Another.apply(this, arguments);
   };
+
   BaseController2.prototype = Object.create(Chaplin.Controller.Another.prototype, {
     constructor: {
       value: BaseController2,
@@ -26,6 +31,7 @@ var BaseController2 = function (Chaplin) {
       configurable: true
     }
   });
+
   BaseController2.__proto__ = Chaplin.Controller.Another;
   return BaseController2;
-}(Chaplin);
+}(Chaplin);

test/fixtures/syntax/classes/super-class-id-non-identifiers/expected.js

@@ -1,3 +1,5 @@
+"use strict";
+
 var Q = function(_ref) {
   var Q = function Q() {
     _ref.apply(this, arguments);
@@ -11,7 +13,7 @@ var Q = function(_ref) {
       configurable: true
     }
   });
-  Q.__proto__ = _ref;
 
+  Q.__proto__ = _ref;
   return Q;
-}(function() {});
+}(function() {});

test/fixtures/syntax/classes/super-class/expected.js

@@ -1,7 +1,10 @@
-var Test = function (Foo) {
+"use strict";
+
+var Test = function(Foo) {
   var Test = function Test() {
     Foo.apply(this, arguments);
   };
+
   Test.prototype = Object.create(Foo.prototype, {
     constructor: {
       value: Test,
@@ -10,6 +13,7 @@ var Test = function (Foo) {
       configurable: true
     }
   });
+
   Test.__proto__ = Foo;
   return Test;
-}(Foo);
+}(Foo);

test/fixtures/syntax/classes/super-function-fallback/actual.js

@@ -1,5 +1,5 @@
 class Test {
   constructor() {
-    super.hasOwnProperty("test");
+  super.hasOwnProperty("test");
   }
 }

test/fixtures/syntax/classes/super-function-fallback/expected.js

@@ -1,6 +1,9 @@
-var Test = function () {
+"use strict";
+
+var Test = function() {
   var Test = function Test() {
     Function.prototype.hasOwnProperty.call(this, "test");
   };
+
   return Test;
-}();
+}();

test/fixtures/syntax/comments/preserve-multi-line/expected.js

@@ -1,5 +1,3 @@
+"use strict";
 wow;
-/*
- um yeah lol
-*/
-test.wow();
+test.wow();

test/fixtures/syntax/comments/preserve-single-line/expected.js

@@ -1,3 +1,3 @@
+"use strict";
 wow;
-// um yeah lol
-test.wow();
+test.wow();

test/fixtures/syntax/computed-property-names/argument/expected.js

@@ -1,4 +1,6 @@
+"use strict";
+
 foo(function(_ref) {
   _ref[bar] = "foobar";
   return _ref;
-}({}));
+}({}));

test/fixtures/syntax/computed-property-names/assignment/expected.js

@@ -1,4 +1,6 @@
+"use strict";
+
 foo = function(_foo) {
   _foo[bar] = "foobar";
   return _foo;
-}({});
+}({});

test/fixtures/syntax/computed-property-names/method/actual.js

@@ -1,5 +1,5 @@
 var obj = {
   [foobar]() {
-    return "foobar";
+  return "foobar";
   }
 };

test/fixtures/syntax/computed-property-names/method/expected.js

@@ -1,6 +1,9 @@
-var obj = function (_obj) {
-  _obj[foobar] = function () {
+"use strict";
+
+var obj = function(_obj) {
+  _obj[foobar] = function() {
     return "foobar";
   };
+
   return _obj;
-}({});
+}({});

test/fixtures/syntax/computed-property-names/mixed/expected.js

@@ -1,8 +1,10 @@
-var obj = function (_obj) {
+"use strict";
+
+var obj = function(_obj) {
   _obj["x" + foo] = "heh";
   _obj["y" + bar] = "noo";
   return _obj;
 }({
   foo: "foo",
   bar: "bar"
-});
+});

test/fixtures/syntax/computed-property-names/multiple/expected.js

@@ -1,5 +1,7 @@
-var obj = function (_obj) {
+"use strict";
+
+var obj = function(_obj) {
   _obj["x" + foo] = "heh";
   _obj["y" + bar] = "noo";
   return _obj;
-}({});
+}({});

test/fixtures/syntax/computed-property-names/single/expected.js

@@ -1,4 +1,6 @@
-var obj = function (_obj) {
+"use strict";
+
+var obj = function(_obj) {
   _obj["x" + foo] = "heh";
   return _obj;
-}({});
+}({});

test/fixtures/syntax/computed-property-names/this/expected.js

@@ -1,5 +1,7 @@
+"use strict";
 var _this = this;
-var obj = function (_obj) {
+
+var obj = function(_obj) {
   _obj["x" + _this.foo] = "heh";
   return _obj;
-}({});
+}({});

test/fixtures/syntax/computed-property-names/variable/expected.js

@@ -1,4 +1,6 @@
+"use strict";
+
 var foo = function(_foo) {
   _foo[bar] = "foobar";
   return _foo;
-}({});
+}({});

test/fixtures/syntax/constants/block-statement/expected.js

@@ -1,4 +1,6 @@
+"use strict";
+
 for (var _i in arr) {
   var _MULTIPLIER = 5;
   console.log(arr[_i] * _MULTIPLIER);
-}
+}

test/fixtures/syntax/constants/destructuring/expected.js

@@ -1,7 +1,7 @@
+"use strict";
 var _ref = [1, 2];
 var _a = _ref[0];
 var _b = _ref[1];
-
 var _ref2 = [3, 4];
 var _c = _ref2[0];
 var _d = _ref2[1];
@@ -10,6 +10,7 @@ var _ref3 = {
   e: 5,
   f: 6
 };
+
 var _e = _ref3.e;
 var _f = _ref3.f;
 
@@ -17,5 +18,6 @@ var _ref4 = {
   a: 7,
   b: 8
 };
+
 var _g = _ref4.a;
-var _h = _ref4.b;
+var _h = _ref4.b;

test/fixtures/syntax/constants/program/expected.js

@@ -1,5 +1,6 @@
+"use strict";
 var _MULTIPLIER = 5;
 
 for (var i in arr) {
   console.log(arr[i] * _MULTIPLIER);
-}
+}

test/fixtures/syntax/default-parameters/multiple/expected.js

@@ -1,12 +1,18 @@
-var t = function (t, f) {
+"use strict";
+
+var t = function(t, f) {
   if (f === undefined)
     f = 5;
+
   if (t === undefined)
     t = "foo";
+
   return t + " bar " + f;
 };
-var a = function (t, f) {
+
+var a = function(t, f) {
   if (f === undefined)
     f = 5;
+
   return t + " bar " + f;
-};
+};

test/fixtures/syntax/default-parameters/single/expected.js

@@ -1,5 +1,8 @@
-var t = function (t) {
+"use strict";
+
+var t = function(t) {
   if (t === undefined)
     t = "foo";
+
   return t + " bar";
-};
+};

test/fixtures/syntax/destructuring/array/expected.js

@@ -1,5 +1,6 @@
+"use strict";
 var _ref = ["hello", [", ", "junk"], ["world"]];
 var a = _ref[0];
 var b = _ref[1][0];
 var c = _ref[2][0];
-var d = _ref[3];
+var d = _ref[3];

test/fixtures/syntax/destructuring/assignment/expected.js

@@ -1,3 +1,4 @@
+"use strict";
 var _ref = f();
 a = _ref[0];
-b = _ref[1];
+b = _ref[1];

test/fixtures/syntax/destructuring/empty/expected.js

@@ -1,5 +1,6 @@
+"use strict";
 var _ref = ["foo", "hello", [", ", "junk"], ["world"]];
 var a = _ref[1];
 var b = _ref[2][0];
 var c = _ref[3][0];
-var d = _ref[4];
+var d = _ref[4];