add support for escodegen-style format options

CHANGELOG.md

@@ -1,3 +1,4 @@
 # 1.11.13
 
  * Update regenerator-6to5
+ * Add support for most escodegen formatting options

lib/6to5/generation/generator.js

@@ -16,29 +16,38 @@ var _          = require("lodash");
 function CodeGenerator(ast, opts, code) {
   opts = opts || {};
 
-  this.style = {
-    semicolons: true,
-    comments: true,
-    compact: false,
-    indent: {
-      char: " ",
-      width: 2
-    }
-  };
-
   this.comments = ast.comments || [];
   this.tokens   = ast.tokens || [];
   this.opts     = opts;
   this.ast      = ast;
   this.buf      = "";
 
-  this._indent = 0;
+  this.format  = CodeGenerator.normaliseOptions(opts);
+  this._indent = this.format.indent.base;
 
   this.whitespace = new Whitespace(this.tokens, this.comments);
   this.position   = new Position;
   this.map        = new SourceMap(this.position, opts, code);
 }
 
+CodeGenerator.normaliseOptions = function (opts) {
+  opts = opts.format || {};
+
+  opts = _.merge({
+    parentheses: true,
+    semicolons: true,
+    comments: true,
+    compact: false,
+    indent: {
+      adjustMultilineComment: true,
+      style: "  ",
+      base: 0
+    }
+  }, opts);
+
+  return opts;
+};
+
 CodeGenerator.generators = {
   arrayComprehensions: require("./generators/array-comprehensions"),
   templateLiterals:    require("./generators/template-literals"),
@@ -58,7 +67,7 @@ _.each(CodeGenerator.generators, function (generator) {
 
 CodeGenerator.prototype.newline = function (i, removeLast) {
   if (!this.buf) return;
-  if (this.style.compact) return;
+  if (this.format.compact) return;
   if (this.endsWith("{\n")) return;
 
   if (_.isBoolean(i)) {
@@ -89,7 +98,7 @@ CodeGenerator.prototype.removeLast = function (cha) {
 };
 
 CodeGenerator.prototype.semicolon = function () {
-  if (this.style.semicolons) this.push(";");
+  if (this.format.semicolons) this.push(";");
 };
 
 CodeGenerator.prototype.ensureSemicolon = function () {
@@ -145,15 +154,15 @@ CodeGenerator.prototype.isLast = function (cha, trimRight) {
 };
 
 CodeGenerator.prototype.getIndent = function () {
-  if (this.style.compact) {
+  if (this.format.compact) {
     return "";
   } else {
-    return util.repeat(this.indentSize(), this.style.indent.char);
+    return util.repeat(this._indent, this.format.indent.style);
   }
 };
 
 CodeGenerator.prototype.indentSize = function () {
-  return this._indent * this.style.indent.width;
+  return this.getIndent().length;
 };
 
 CodeGenerator.prototype.indent = function () {
@@ -353,8 +362,8 @@ CodeGenerator.prototype._getComments = function (key, node) {
 };
 
 CodeGenerator.prototype._printComments = function (comments) {
-  if (this.style.compact) return;
-  if (!this.style.comments) return;
+  if (this.format.compact) return;
+  if (!this.format.comments) return;
   if (!comments || !comments.length) return;
 
   var self = this;
@@ -373,14 +382,16 @@ CodeGenerator.prototype._printComments = function (comments) {
 
     //
 
-    var offset = comment.loc.start.column;
-    if (offset) {
-      var newlineRegex = new RegExp("\\n\\s{1," + offset + "}", "g");
-      val = val.replace(newlineRegex, "\n");
-    }
+    if (comment.type === "Block" && self.format.indent.adjustMultilineComment) {
+      var offset = comment.loc.start.column;
+      if (offset) {
+        var newlineRegex = new RegExp("\\n\\s{1," + offset + "}", "g");
+        val = val.replace(newlineRegex, "\n");
+      }
 
-    var indent = Math.max(self.indentSize(), column);
-    val = val.replace(/\n/g, "\n" + util.repeat(indent));
+      var indent = Math.max(self.indentSize(), column);
+      val = val.replace(/\n/g, "\n" + util.repeat(indent));
+    }
 
     if (column === 0) {
       val = self.getIndent() + val;

lib/6to5/generation/generators/expressions.js

@@ -44,9 +44,11 @@ exports.ConditionalExpression = function (node, print) {
 exports.NewExpression = function (node, print) {
   this.push("new ");
   print(node.callee);
-  this.push("(");
-  print.join(node.arguments, { separator: ", " });
-  this.push(")");
+  if (node.arguments.length || this.format.parentheses) {
+    this.push("(");
+    print.join(node.arguments, { separator: ", " });
+    this.push(")");
+  }
 };
 
 exports.SequenceExpression = function (node, print) {