Allow whitespace control on comments

This changes the call signature for the CommentNode constructor, which is a potentially breaking change for AST users.

Fixes #866

lib/handlebars/compiler/ast.js

@@ -196,14 +196,13 @@ var AST = {
     this.stringModeValue = bool === "true";
   },
 
-  CommentNode: function(comment, locInfo) {
+  CommentNode: function(comment, strip, locInfo) {
     LocationInfo.call(this, locInfo);
     this.type = "comment";
     this.comment = comment;
 
-    this.strip = {
-      inlineStandalone: true
-    };
+    this.strip = strip;
+    strip.inlineStandalone = true;
   }
 };
 

lib/handlebars/compiler/helpers.js

@@ -7,6 +7,11 @@ export function stripFlags(open, close) {
   };
 }
 
+export function stripComment(comment) {
+  return comment.replace(/^\{\{~?\!-?-?/, '')
+                .replace(/-?-?~?\}\}$/, '');
+}
+
 
 export function prepareBlock(mustache, program, inverseAndProgram, close, inverted, locInfo) {
   /*jshint -W040 */

spec/ast.js

@@ -137,7 +137,7 @@ describe('ast', function() {
   describe("CommentNode", function(){
 
     it('stores location info', function(){
-      var comment = new handlebarsEnv.AST.CommentNode("HI", LOCATION_INFO);
+      var comment = new handlebarsEnv.AST.CommentNode("HI", {}, LOCATION_INFO);
       testLocationInfoStorage(comment);
     });
   });

spec/basic.js

@@ -33,6 +33,9 @@ describe("basic context", function() {
     shouldCompileTo("{{! Goodbye}}Goodbye\n{{cruel}}\n{{world}}!",
       {cruel: "cruel", world: "world"}, "Goodbye\ncruel\nworld!",
       "comments are ignored");
+
+    shouldCompileTo('    {{~! comment ~}}      blah', {}, 'blah');
+    shouldCompileTo('    {{~!-- long-comment --~}}      blah', {}, 'blah');
   });
 
   it("boolean", function() {

spec/tokenizer.js

@@ -217,19 +217,19 @@ describe('Tokenizer', function() {
   it('tokenizes a comment as "COMMENT"', function() {
     var result = tokenize("foo {{! this is a comment }} bar {{ baz }}");
     shouldMatchTokens(result, ['CONTENT', 'COMMENT', 'CONTENT', 'OPEN', 'ID', 'CLOSE']);
-    shouldBeToken(result[1], "COMMENT", " this is a comment ");
+    shouldBeToken(result[1], "COMMENT", "{{! this is a comment }}");
   });
 
   it('tokenizes a block comment as "COMMENT"', function() {
     var result = tokenize("foo {{!-- this is a {{comment}} --}} bar {{ baz }}");
     shouldMatchTokens(result, ['CONTENT', 'COMMENT', 'CONTENT', 'OPEN', 'ID', 'CLOSE']);
-    shouldBeToken(result[1], "COMMENT", " this is a {{comment}} ");
+    shouldBeToken(result[1], "COMMENT", "{{!-- this is a {{comment}} --}}");
   });
 
   it('tokenizes a block comment with whitespace as "COMMENT"', function() {
     var result = tokenize("foo {{!-- this is a\n{{comment}}\n--}} bar {{ baz }}");
     shouldMatchTokens(result, ['CONTENT', 'COMMENT', 'CONTENT', 'OPEN', 'ID', 'CLOSE']);
-    shouldBeToken(result[1], "COMMENT", " this is a\n{{comment}}\n");
+    shouldBeToken(result[1], "COMMENT", "{{!-- this is a\n{{comment}}\n--}}");
   });
 
   it('tokenizes open and closing blocks as OPEN_BLOCK, ID, CLOSE ..., OPEN_ENDBLOCK ID CLOSE', function() {

src/handlebars.l

@@ -56,7 +56,10 @@ ID    [^\s!"#%-,\.\/;->@\[-\^`\{-~]+/{LOOKAHEAD}
                                  }
 <raw>[^\x00]*?/("{{{{/")         { return 'CONTENT'; }
 
-<com>[\s\S]*?"--}}"              strip(0,4); this.popState(); return 'COMMENT';
+<com>[\s\S]*?"--"{RIGHT_STRIP}?"}}" {
+  this.popState();
+  return 'COMMENT';
+}
 
 <mu>"("                          return 'OPEN_SEXPR';
 <mu>")"                          return 'CLOSE_SEXPR';
@@ -76,8 +79,15 @@ ID    [^\s!"#%-,\.\/;->@\[-\^`\{-~]+/{LOOKAHEAD}
 <mu>"{{"{LEFT_STRIP}?\s*"else"   return 'OPEN_INVERSE';
 <mu>"{{"{LEFT_STRIP}?"{"         return 'OPEN_UNESCAPED';
 <mu>"{{"{LEFT_STRIP}?"&"         return 'OPEN';
-<mu>"{{!--"                      this.popState(); this.begin('com');
-<mu>"{{!"[\s\S]*?"}}"            strip(3,5); this.popState(); return 'COMMENT';
+<mu>"{{"{LEFT_STRIP}?"!--" {
+  this.unput(yytext);
+  this.popState();
+  this.begin('com');
+}
+<mu>"{{"{LEFT_STRIP}?"!"[\s\S]*?"}}" {
+  this.popState();
+  return 'COMMENT';
+}
 <mu>"{{"{LEFT_STRIP}?            return 'OPEN';
 
 <mu>"="                          return 'EQUALS';

src/handlebars.yy

@@ -18,7 +18,7 @@ statement
   | rawBlock -> $1
   | partial -> $1
   | CONTENT -> new yy.ContentNode($1, @$)
-  | COMMENT -> new yy.CommentNode($1, @$)
+  | COMMENT -> new yy.CommentNode(yy.stripComment($1), yy.stripFlags($1, $1), @$)
   ;
 
 rawBlock