better whitespace for code generation

lib/6to5/generators/array-comprehensions.js

@@ -9,15 +9,15 @@ exports.ComprehensionBlock = function (node, print) {
 
 exports.ComprehensionExpression = function (node, print) {
   this.push("[");
-  this.printJoin(print, node.blocks, " ");
-  this.push(" ");
+  this.printJoin(print, node.blocks, { separator: " " });
+  this.space();
 
   if (node.filter) {
     this.keyword("if");
     this.push("(");
     print(node.filter);
     this.push(")");
-    this.push(" ");
+    this.space();
   }
 
   print(node.body);

lib/6to5/generators/base.js

@@ -13,7 +13,7 @@ exports.BlockStatement = function (node, print) {
     this.push("{");
     this.newline();
     print.sequence(node.body, { indent: true });
-    this.newline(true);
-    this.push("}");
+    this.removeLast("\n");
+    this.rightBrace();
   }
 };

lib/6to5/generators/classes.js

@@ -3,7 +3,7 @@ exports.ClassDeclaration = function (node, print) {
   this.push("class");
 
   if (node.id) {
-    this.push(" ");
+    this.space();
     print(node.id);
   }
 
@@ -12,7 +12,7 @@ exports.ClassDeclaration = function (node, print) {
     print(node.superClass);
   }
 
-  this.push(" ");
+  this.space();
   print(node.body);
 };
 
@@ -27,7 +27,6 @@ exports.ClassBody = function (node, print) {
     print.sequence(node.body);
     this.dedent();
 
-    this.newline(true);
-    this.push("}");
+    this.rightBrace();
   }
 };

lib/6to5/generators/expressions.js

@@ -1,13 +1,19 @@
 var t = require("../types");
 
 exports.UnaryExpression = function (node, print) {
-  this.push(node.operator);
-
+  var hasSpace = /[a-z]$/.test(node.operator);
   var arg = node.argument;
-  if (/[a-z]$/.test(node.operator) || t.isUpdateExpression(arg) || t.isUnaryExpression(arg)) {
-    this.push(" ");
+
+  if (t.isUpdateExpression(arg) || t.isUnaryExpression(arg)) {
+    hasSpace = true;
   }
 
+  if (t.isUnaryExpression(arg) && arg.operator === "!") {
+    hasSpace = false;
+  }
+
+  this.push(node.operator);
+  if (hasSpace) this.space();
   print(node.argument);
 };
 
@@ -29,18 +35,16 @@ exports.ConditionalExpression = function (node, print) {
   print(node.alternate);
 };
 
-exports.NewExpression = function (node, print) {
+exports.NewExpression = function (node, print, parent) {
   this.push("new ");
   print(node.callee);
-  if (node.arguments.length) {
-    this.push("(");
-    this.printJoin(print, node.arguments, ", ");
-    this.push(")");
-  }
+  this.push("(");
+  this.printJoin(print, node.arguments, { separator: ", " });
+  this.push(")");
 };
 
 exports.SequenceExpression = function (node, print) {
-  this.printJoin(print, node.expressions, ", ");
+  this.printJoin(print, node.expressions, { separator: ", " });
 };
 
 exports.ThisExpression = function () {
@@ -50,7 +54,7 @@ exports.ThisExpression = function () {
 exports.CallExpression = function (node, print) {
   print(node.callee);
   this.push("(");
-  this.printJoin(print, node.arguments, ", ");
+  this.printJoin(print, node.arguments, { separator: ", " });
   this.push(")");
 };
 
@@ -58,7 +62,7 @@ exports.YieldExpression = function (node, print) {
   this.push("yield");
   if (node.delegate) this.push("*");
   if (node.argument) {
-    this.push(" ");
+    this.space();
     print(node.argument);
   }
 };

lib/6to5/generators/jsx.js

@@ -65,8 +65,8 @@ exports.XJSOpeningElement = function (node, print) {
   this.push("<");
   print(node.name);
   if (node.attributes.length > 0) {
-    this.push(" ");
-    this.printJoin(print, node.attributes, " ");
+    this.space();
+    this.printJoin(print, node.attributes, { separator: " " });
   }
   this.push(node.selfClosing ? " />" : ">");
 };

lib/6to5/generators/methods.js

@@ -5,7 +5,8 @@ exports._params = function (node, print) {
 
   this.push("(");
 
-  this.printJoin(print, node.params, ", ", {
+  this.printJoin(print, node.params, {
+    separator: ", ",
     iterator: function (param, i) {
       var def = node.defaults && node.defaults[i];
       if (def) {
@@ -49,7 +50,7 @@ exports._method = function (node, print) {
   }
 
   this._params(value, print);
-  this.push(" ");
+  this.space();
   print(value.body);
 };
 
@@ -64,7 +65,7 @@ exports.MethodDefinition = function (node, print) {
 exports.ReturnStatement = function (node, print) {
   this.push("return");
   if (node.argument) {
-    this.push(" ");
+    this.space();
     print(node.argument);
   }
   this.semicolon();
@@ -74,10 +75,10 @@ exports.FunctionDeclaration =
 exports.FunctionExpression = function (node, print) {
   this.push("function");
   if (node.generator) this.push("*");
-  this.push(" ");
+  this.space();
   if (node.id) print(node.id);
   this._params(node, print);
-  this.push(" ");
+  this.space();
   print(node.body);
 };
 

lib/6to5/generators/modules.js

@@ -31,9 +31,9 @@ exports.ExportDeclaration = function (node, print) {
     } else {
       this.push("{");
       if (specifiers.length) {
-        this.push(" ");
-        this.printJoin(print, specifiers, ", ");
-        this.push(" ");
+        this.space();
+        this.printJoin(print, specifiers, { separator: ", " });
+        this.space();
       }
       this.push("}");
     }

lib/6to5/generators/statements.js

@@ -13,12 +13,12 @@ exports.IfStatement = function (node, print) {
   print(node.test);
   this.push(") ");
 
-  print(node.consequent);
+  this.printAndIndentOnComments(print, node.consequent);
 
   if (node.alternate) {
-    if (this.isLast("}")) this.push(" ");
+    if (this.isLast("}")) this.space();
     this.keyword("else");
-    print(node.alternate);
+    this.printAndIndentOnComments(print, node.alternate);
   }
 };
 
@@ -30,13 +30,13 @@ exports.ForStatement = function (node, print) {
   this.push(";");
 
   if (node.test) {
-    this.push(" ");
+    this.space();
     print(node.test);
   }
   this.push(";");
 
   if (node.update) {
-    this.push(" ");
+    this.space();
     print(node.update);
   }
 
@@ -73,10 +73,11 @@ exports.ForOfStatement = function (node, print) {
 };
 
 exports.DoWhileStatement = function (node, print) {
-  this.push("do ");
+  this.keyword("do");
   print(node.body);
-  this.push(" while");
-  this.push(" (");
+  this.space();
+  this.keyword("while");
+  this.push("(");
   print(node.test);
   this.push(");");
 };
@@ -84,7 +85,7 @@ exports.DoWhileStatement = function (node, print) {
 exports.BreakStatement = function (node, print) {
   this.push("break");
   if (node.label) {
-    this.push(" ");
+    this.space();
     print(node.label);
   }
   this.semicolon();
@@ -93,7 +94,7 @@ exports.BreakStatement = function (node, print) {
 exports.ContinueStatement = function (node, print) {
   this.push("continue");
   if (node.label) {
-    this.push(" ");
+    this.space();
     print(node.label);
   }
   this.semicolon();
@@ -108,10 +109,11 @@ exports.LabeledStatement = function (node, print) {
 exports.TryStatement = function (node, print) {
   this.keyword("try");
   print(node.block);
-  this.push(" ");
+  this.space();
   print(node.handler);
   if (node.finalizer) {
-    this.push(" finally ");
+    this.space();
+    this.push("finally ");
     print(node.finalizer);
   }
 };
@@ -135,14 +137,17 @@ exports.SwitchStatement = function (node, print) {
   this.push("(");
   print(node.discriminant);
   this.push(") {");
-
-  if (node.cases.length > 0) {
-    this.newline();
-    print.sequence(node.cases, { indent: true });
-    this.newline();
-  }
-
+  print.sequence(node.cases, { indent: true });
   this.push("}");
+
+  //if (node.cases.length) {
+  //  this.newline();
+  //  print.sequence(node.cases, { indent: true });
+  //  this.newline();
+  //  this.rightBrace();
+  //} else {
+  //  this.push("}");
+  //}
 };
 
 exports.SwitchCase = function (node, print) {
@@ -155,7 +160,7 @@ exports.SwitchCase = function (node, print) {
   }
 
   if (node.consequent.length === 1) {
-    this.push(" ");
+    this.space();
     print(node.consequent[0]);
   } else if (node.consequent.length > 1) {
     this.newline();
@@ -170,7 +175,7 @@ exports.DebuggerStatement = function () {
 exports.VariableDeclaration = function (node, print, parent) {
   this.push(node.kind + " ");
 
-  this.printJoin(print, node.declarations, ", ");
+  this.printJoin(print, node.declarations, { separator: ", " });
 
   if (!t.isFor(parent)) {
     this.semicolon();

lib/6to5/generators/template-literals.js

@@ -6,7 +6,7 @@ exports.TaggedTemplateExpression = function (node, print) {
 };
 
 exports.TemplateElement = function (node) {
-  this.push(node.value.raw, true);
+  this._push(node.value.raw);
 };
 
 exports.TemplateLiteral = function (node, print) {

lib/6to5/generators/types.js

@@ -15,17 +15,11 @@ exports.ObjectPattern = function (node, print) {
 
   if (props.length) {
     this.push("{");
+    this.space();
 
-    if (props.length === 1) {
-      this.push(" ");
-      this.print(props[0]);
-      this.push(" ");
-    } else {
-      this.newline();
-      this.printJoin(print, props, ",\n", { indent: true });
-      this.newline();
-    }
+    this.printJoin(print, props, { separator: ", ", indent: true });
 
+    this.space();
     this.push("}");
   } else {
     this.push("{}");